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MM 006 : Cold Rolled
INTRODUCTION
Cold Rolled carbon sheet steel is manufactured from hot rolled pickled coils by cold reducing to the ordered thickness followed by annealing to
recrystallize the grain structure. The annealed product can be used as-annealed (dead soft) for unexposed applications. For exposed applications the
annealed sheet product is given a skin or temper pass to minimize the phenomenon known as stretcher strains or fluting and to impart suitable surface
texture. Cold rolled sheet steel can be furnished in the full hard (un annealed) condition. Where cold rolled sheet steel is used for fabrication by welding,
chemical composition and mechanical properties should be considered to assure compatibility with the welding process and its effect on altering the
properties.
HOW COLD ROLLED SHEETS ARE MADE
PICKLING
During hot rolling and cooling operations, surface oxides develop which, if not removed, could be rolled into the surface of the sheet during cold
reduction and result in surface defects. Pickling is the use of an acid solution which removes these oxides. During this process other functions are also
performed at the continuous pickling unit:
A. After hot rolled coil ends are cropped, the coils are soundly butt welded together to permit a continuous pickling operation, to build large production
coils for further processing and to satisfy customer's individual coil weight requirements.
B. Edges are side trimmed to meet the ordered width requirement and also make edges uniform for cold reduction and further processing.
C. Inspection of surface.
D. Oil is applied at the exit end of the pickler, to inhibit oxidation of the surface of the deaned steel and to serve as a lubricant for the cold reduction
operation.
COLD REDUCTION
Cold reduction is the sequential rolling of the pickled and oiled coils through tandem mills to achieve desired thickness. The number of mills, or stands, in
tandem generally ranges from 3 to 5. This operation also helps to impart desired surface and shape characteristics. Because of the severe cold reduction,
usually 50% or more, the sheet is now in the "full hard" condition and is usually processed further to develop desired properties such as formability,
flatness and surface texture.
BOX ANNEALING
Cold-reduced steel is usually "full hard" in the as-rolled condition. The grain structure is recrystallized through various heat treating cycles in a box
annealing furnace to put the steel in a suitable condition for shipment as "annealed last" sheets or for further mill processing. Box annealing equipment
consists of: annealing bases on which to place the steel and inner covers to fit over the charge to contain a protective gas atmosphere that prevents
oxidation of the steel and furnaces in which to apply the heat. Fuel of controlled consistency is burned inside the furnace. Primarily radiant heat at
temperatures of 1,000 -1,400 degrees Fahrenheit passes through the protective inner covers and is absorbed by the steel. The entire box-annealing cycle
(heat - cool) takes several days. After box-annealing, the product is in a condition known as "dead soft" or "annealed last". In this state the material is
often used for unexposed parts and is quite ductile, but stretcher straining and fluting tendencies are characteristics of "annealed last" product.
CONTINUOUS ANNEALING
Continuous annealing is a process in which steel coils are unwound and passed through a furnace where they are subjected to a prescribed annealing
cycle under a protective atmosphere. The furnace has both heating and cooling zones and may also contain some type of quenching capability as well as
an over aging section. Temperatures, line speeds and cooling rates are controlled to obtain the desired mechanical properties for the chemistry of the
steel being heat treated. Normally, continuous annealing lines are equipped with entry and exit accumulators that allow coils 10 be welded to one another
so that the annealing proceeds uninterrupted. After annealing, coils often receive further processing such as temper rolling, galvanizing, etc. About 4 to 8
min are required to continuously anneal a coil of steel. Because of the much shorter duration of a continuous -anneal cycle versus a batch-annealed cycle,
higher temperatures are generally necessary. A typical range for most cold-rolled grades is 1,200 to 1,500 degrees Fahrenheit (650 to 815 degrees
Celsius).
TEMPER ROLLING
Temper rolling is a light, carefully controlled cold rolling of»ration that is employed after box annealing to:
1. Improve flatness
2. Produce the final finish or texture
3. Develop required (as shipped) mechanical properties
4. Reduce the tendency of "stretcher strain" or "flute" in forming or drawing.
Product Description
Cold Rolled Sheet - Class 1
Class 1 Is intended (or critical surface quality applications). Surface quality standards assure freedom from minor surface imperfections; typically used
for : exposed surface, surface critical, and is inspected at the mill. Class 1 is intended for exposed applications where surface appearance is of primary
importance. This class will meet requirements for controlled surface texture, surface quality and flatness. It is normally processed by the producer to be
free of stretcher strain and fluting. Subsequent consumer roller levelling immediately before fabrication will minimize strain resulting from aging.
However, when drawing steel special killed is specified roller levelling may not be required. Processed to meet requirements for controlled surface texture
(i.e., regular matte, light matte, commercial bright, luster, embossed), flatness limitations and temper requirements. When cut-length sheet is ordered, the
mill rejects individual sheet having major surface imperfections and repetitive minor surface imperfections. Cut-length sheet may have random minor
surface imperfections. Sheet in coils should be expected to contain major surface imperfections and more minor imperfections than cut-lengths. Coil may
contain welds. APPLICATIONS : Used when surface textures and conditions, flatness and ductility affect quality of the end product.
Cold Rolled Sheet - Class 2
Class 2 Is intended for unexposed or non-critical surface quality applications where surface uniformity and appearance are not the primary
requirements; unexposed surface, non surface critical, not inspected at the mill, and is sometimes Class I rejects. This product is easily painted, welded,
and formed within the limits of the quality designator and the intended application. This product is produced to the flatness standards of Class 1 and is
free of strains and coll breaks. Surface quality standards permit occurrences of minor cosmetic surface imperfections such as pits, slivers, scratches,
slicker breaks, and edge breaks (3/8 inch maximum). When Class 2 is ordered as Annealed Last (Dead Soil), the product can offer improved ductility over
the temper rolled equivalent in certain forming applications. The final operation in manufacturing this product is to pass it through a temper mill or a
recoil line in order to apply oil. This product is subject to strains, fluting and coil breaks. Restrictions on surface finish or standard flatness tolerances do
not apply. Surface quality standards are the same as for a tempered product.
Class 2 is generally intended for unexposed applications only. It is normally produced without temper rolling, but may be lightly rolled in the process of
oiling or rewinding. This class can be expected to have coil breaks, fluffing and stretcher straining. Standard tolerances for flatness and surface texture are
not applicable. In addition, surface imperfections are more prevalent than with Class 1 because steel applications, processing procedures and inspection
standards are less stringent.
Class 2 • Tempered Brief Facts:
• All purpose sheet where surface appearance is not of primary importance.
• Limitations on surface texture or surface roughness are not applicable.
• Processed to meet flatness limitations of class 1.
• Freedom from straining, crossbreaks and pinchers.
• Minor surface imperfections such as pits, scratches, sticker breaks, roll marks may be expected.
• Major surface imperfections such as holes and loose slivers may be present in coils.
• Very little Class 2 cold rolled non-tempered sold in this country.
• Most product Class 2 is tempered that is sold in this country.
• Finest ductile steel is (especially drawing quality) continuous cast.
APPLICATIONS: Used for unexposed parts and exposed parts where surface appearance Is not of primary Importance. Not suitable for continuous
coll painting.
Class 2 - Non-Tempered Brief Facts:
• Economy sheet where surface appearance is not of primary importance.
• Limitations on surface texture or surface roughness and: tempers are not applicable.
• Subject to stretcher strains and fluting.
• Will normally be within twice the standard flatness tolerances in cut lengths and after removal of coil set in coils.
• Coils and cut lengths' must be expected to contain minor surface imperfections such as pits, scratches, sticker breaks, edge breaks, pinchers, cross
breaks, roll marks and other minor surface imperfections.
• Major surface imperfections such as holes and loose slivers may be present in coils.
APPLICATIONS: Used when surface texture or condition Is not Important to appearance of finished product and maximum formabllity is desired. Not
suitable for continuous coil painting.
COLD ROLLED FINISHES
ROUGH MATTE (#4) -70 to 150 Microinch Finish
REGULAR MATTE (#6) - 30 to 60 Microinch Finish
LIGHT MATTE (#7) - 20 to 45 Microinch Finish
DUST BRIGHT (#9) - 20 max. Microinch Finish
COMMERCIAL BRIGHT (#10) - 10 max. Microinch Finish
COLD ROLLED SHEET & COIL
PRODUCT CLASSIFICATION BY SIZE
Thickness (inches)
.250 and .249 to .014 and
Width (inches) thicker .014 thinner
Thru l2 Bar Strip (1,2) Strip(1)
2-12 Bar Strip (3) Strip
Over 12 - 23 15/16 Strip (2) Strip (2) Strip
Over 12 Sheet (4) Sheet (4) Black Plate
(1)Flat Wire: When the width is greater than the thickness with a maximum width of 1/2" and cross-sectional area not exceeding .05 square inches and
the material has rolled or prepared edges.
(2)CR Strip: When a finish or temper or ecge as numerically identified in ASTM A-W9, is specified, or when single strand rolling is specified on widths
over 1/2".
(3)CR Slit Sheet: Cold Rolled Sheet coils in widths 2" through 12", slit from multiple strand coils and furnished to slit sheet thickness and dimensional
tolerances.
(4)CR Sheet: When none of the features of Note (2) above are specified or required.
COLD ROLLED SHEET & COIL INDUSTRY DESIGNATIONS/QUALITY SPECIFICATIONS
AISI - SAE Grades: (Standard) Chemical limits
Steel designations Carbon Manganese
1006 0.08 max. 0.45 max.
1008 0.10 max. 0.45 max.
1009 0.15 max. 0.60 max.
1010 0.08 - 0.13 0.30 - 0.60
1012 0.10 - 0.15 0.30 - 0.60
1015 0.12 - 0.18 0.30 - 0.60
Specified Chemistry
Customer can specify their carbon and manganese ranges - as well as limiting phosphorus...copper...sulfur...and other additions. (These chemistry
restrictions require special mill ordering practices.)
ASTM QUALITY SPECIFICATIONS
A-1008 Combined specification for the old A-366 CR Commercial Steel, A-607 High-Strength with Columbium or Vanadium, A-611 Structural Steel, A-
620 Drawing Steel SK, A-963 Deep Drawing Steel, A-969 Extra Deep Drawing Steel
A-794 CR Commercial Steel with Carbon .16/.25
A-606 Improved Corrosion Resistance
Full Hard and Intermediate Tempers
It is conventional to determine the surface hardness of Cold Rolled Carbon Steel Sheets as a "Rockwell Hardness Number" derived from the measured
depth of impression of a carbide ball on a test specimen. The Rockwell "T" scale is commonly used (its values can be converted to other scales such as
15-T and 30-T). The lower the Rockwell value, the softer the steel.
Full Hard
A very stiff cold rolled sheet. Rockwell hardness, B scale: 84 (minimum]}.
Half-Hard
A medium stiff cold rolled sheet. Rockwell hardness, B scale: 70-85 at tiime of shipment. (Aging may result in a slightly greater hardness when tested at
a later time.)
Quarter-Hard
A moderately stiff cold rolled sheet. Rockwell hardness, B scale: 60-75 at time of shipment. (Aging may result in a slightly greater hardness when
tested at a later time.)
'When a cold rolled carbon steel sheet is specified to hardness limits, it is necessary to employ restricted chemical composition limits, special mill
processing practices, or both. Cold-rolled sheets specified as full hard on-intermediate tempers are not subject to any definite forming requirements or to
flatness tolerances. For cold rolled sheets specified to hardness ranges other than those shown for quarter-hard and half-hard tempers, the specified
Rockwell B range is customarily 15 points.
COLD ROLLED PRODUCT DESCRIPTIONS Cold Rolled Sheet Steel is available in 33 grades/descriptions in ASTM A1008, 2 grades/descriptions in
ASTM A606, and 7 typical grades/descriptions in ASTM A794.
C%, max. Mn% max.
Commercial Steel Type A ..lO% .60 Stabilized at producers option
Commercial Steel Type B . 02/.15% .60
Commercial Steel Type C .08 .60 P .100% max. Stabilized at producers option
Drawing Steel Type A .08 .50
Drawing Steel Type B .02/.08 .50
Deep Drawing Steel .06 .50 Stabilized at producers option
Extra Deep Drawing Steel .02 .40 Stabilized
Structural Steel Carbon Manganese
Structural Steel Carbon Manganese V, Nb(Cb), Ti
Structural Steel Strain hardening
Structural Steel Bake hardening
Ordered to specified mechanical properties. The choice of one of these descriptions can be made in one or more of the following ways:
1. Examination of a drawing.
2. Examination of a completed part, plus experienced judgment of ductility requirements.
3. Previous history of similar parts.
Usually, sheet is ordered by specifying only the description - CS, DDS, EDDS, SS, HSLA, SHS, or BHS. On occasion, a customer may find it necessary
to specify cold rolled sheet to both chemical composition and mechanical properties. When this situation occurs, the compatibility of required
properties and steel composition must be determined.
COMMERCIAL STEEL (CS)
Commercial steels are less ductile than drawing steels, and they can be expected to show wider variations in mechanical properties and chemical
composition. CS sheets are also subject to some loss of ductility with time. Commercial steels are ordinarily produced to a low carbon level and are
suitable for exposed parts requiring a good surface finish. The sheets are normally produced with a matte finish for the application of various organic
finishes, such as paints, enamels and lacquers. If the sheets are to be essentially free from stretcher strains during fabrication, they should be roller
leveled just before the forming operation.
DRAWING STEEL (DS, DDS, EDDS)
Drawing steels are more ductile and more uniform in chemical composition than commercial steels. Drawing steels are manufactured to have good
uniform drawing properties for use in fabricating parts having sever deformations. Drawing steels are not normally specified to a chemical composition
and are generally furnished for use in fabricating an identified part with severe drawing and/or forming. The customer normally furnishes information to
the producer on the individual requirements of the identified part. Drawing steels are usually produced with a matte finish. Neither commercial bright
nor luster finish are compatible with severe drawing requirement to which these grades are usually subjected. DDS & EDDS should be specified where
the formed material is to be essentially free of such surface disturbances as stretcher strains or fluting without the need of prior roller leveling.
STRUCTURAL STEELS (SS, HSLA, SHS, BHS)
Produced when mechanical properties are required, usually to an ASTM or customer specification.
COLD ROLLED TYPICAL MECHANICAL PROPERTIES
Yield Strength KSI %E (2") R Bar N value
Designation
CS Type A, B & C : 20/40 30 ---- ----
DS Type A & B 22/35 36 1.3/1.7 .17/.22
DDS 17/29 38 1.4/1.8 .20/.25
EDDS 15/25 40 1.7/2.1 .23/27
COLD ROLLED SHEET & COIL HIGH STRENGTH STEELS
High Strength Steels are used for weight reduction, increased strength / durability, and cost reduction. These grades are used in place of conventional low
carbon sheet steels. Switching to a high strength steel when designing or redesigning a product can bring significant gains to a customer.
Advantages include:
• Less component weight through reduced section thickness
• Lower costs
• Greater strength.
• And, in some cases, better atmospheric corrosion resistance
Interest in high-strength steels has further increased as more of these grades have been developed with fabricating and welding characteristics closer to
those of conventional sheet steels. For an end user to gain these important advantages, high strength steels must be selected carefully and designed
properly into the product. The steel industry groups its high strength steels by yield strength. Having a variety of steels at each strength level enables
users to select the most efficient and economical product for a given application.
Properties
When a component design calls for a certain minimum yield strength, a designer naturally will want to use the lowest priced steel available with that
strength. But properties other than yield strength should be considered. These properties might include formability, weld ability, tensile strength, fatigue
strength, stiffness, (modulus), impact resistance and corrosion resistance. These properties, as well as cost, vary among the steels available at each
strength level. The steel industry can provide technical assistance in selecting the high-strength steel that has the right combination of properties for
your application.
Sheet products are classified as High Strength when the minimum specified yield strength is 35,000 psi or greater. High strength sheets are sold to
strength levels regardless of the chemical composition. All the High Strength products are identified by a designator system. Use of the designator
permits a more accurate appraisal of customers' needs and product performance requirements. High Strength grades are used where higher strength or
weight reduction is required. Principle applications are for structural, automotive and agricultural applications.
Availability
High Strength Sheet is available in the approximate size range of Carbon Sheet. The increased work load on the rolling mills, coupled with a minimum
thickness reduction causes some limitations on minimum thicknesses and maximum widths.
HIGH STRENGTH LOW ALLOY SHEET STEEL
High strength low alloy sheet steel represents a group of steels having higher strength values, improved formability, weld ability, and/or atmospheric
corrosion resistance than normally obtained from conventional carbon structural steels. These desirable properties are obtained through selected chemical
composition and controlled mill processing. High strength low alloy steels lend themselves to applications where weight reduction* is a major factor. In
some cases this can be done without changing the application. In other cases anything from a minor to a major redesign of the components may be
necessary. High strength low alloy steel is produced -with emphasis on mechanical properties in the as rolled condition.
The yield point and tensile strength requirements most often specified as minimum vary within the following range:
• Yield Point .................... 35,000 psi to 80,000 psi
• Tensile Strength ............ 55,000 psi to 90,000 psi
These high strength low allow sheet steels utilize alloy additions and mill processing techniques to obtain unique properties within the full range of
strength levels given, whereas conventional carbon structural quality sheet steel (without alloying) is available only in the lower strength levels of the
ranges listed.
TYPES
High strength low alloy sheet steel is not available in the four principle qualities commonly used for other sheet steel products (i.e. CS, DS, DDS, and
EDDS ). However, this product is available in the following types:
• Conventional
• Improved Atmospheric Corrosion Resistance
• Improved Formability
Because high strength low alloy sheet steels are characterized by their mechanical properties , the strength and forming requirements may not be
compatible. Care must be taken in designing parts, tooling and fabrication processes to maximize utilization of the high strength low alloy sheet steels. It
is important that the purchaser furnish information to the producer relating the individual requirements of an identified part. Also; it is highly desirable
to observe the fabricating practices, or, at least provide a detailed description of the operations. The wide variety of chemical compositions provides a
wide variety of forming characteristics. Certain compositions are suited for the more demanding forming applications while others are designed primarily
to provide superior atmospheric corrosion resistance or weld ability. Therefore, it is recommended that the purchaser consult with the producer to
determine that the correct type of high strength low alloy sheet steel will be specified.
The types of high strength low alloy sheet steel may be specified to the following ASTM A1008 specification. This ASTM standard includes all the
individual chemical compositions and strength levels produced.
.
Conventional Type (old ASTM A607 "STEEL SHEET AND STRIP, HOT-ROLLED AND COLD-ROLLED. HIGH-STRENGTH, LOW ALLOY
COLUMBIUM AND/OR VANADIUM") This type is produced to various strength levels where atmospheric corrosion resistance and maximum
formability are not a requirement.
NOT INCLUDED IN ASTM A1008 - Improved Atmospheric Corrosion Resistance Type - ASTM A606 "STEEL SHEET AND STRIP, HOT-
ROLLED AND COLD-ROLLED, HIGH-STRENGTH, LOW-ALLOY WITH IMPROVED CORROSION RESISTANCE". This type is produced to
45,000 psi or 50,000 psi minimum yield points. To enhance atmospheric corrosion resistance two types of steel are available. Type 2 having corrosion
resistance of at least two times that of plain carbon steel is usually produced with a copper addition. Type 4 having corrosion resistance of at least four
times that of plain carbon steel is produced with a variety of alloying elements to achieve the desired effect. The consumer should consult the producer
for specific atmospheric corrosion resistance data.
Improved Formability Type (OLD ASTM A715 "STEEL SHEET AND STRIP, HOT-ROLLED, HIGH-STRENGTH, LOW-ALLOY, WITH
IMPROVED FORMABILITY"). This type is produced with special forming properties to various strength levels where maximum formability is
required. It is normally supplied with sulfide inclusion control. This type is generally furnished for use in fabricating an identified part too difficult for
the fabricating properties of the two types listed.
DIMENSIONAL CLASSIFICATION FOR COLD ROLLED CARBON, HIGH STRENGTH LOW ALLOY AND ALLOY SHEET STEEL
Thickness, inch
Width, inch
Carbon and Carbon Carbon HSLA Alloy
Alloy Strip Black Plate Sheet Sheet Sheet
Thru 2 Thru 0.2499
2 - 12 Thru 0.2499 .0142 - .01821 a .0195 - .0821 b
Over 12 - 23 15/16 Thru 0.2499 under .014 .0142 & thicker .0284 & thicker thru .2299
23 15/16 - 48 under .014 .0142 & thicker .0284 & thicker thru .1799
Over 48 .0142 & thicker .0284 & thicker
a Produced by slitting from wider sheet
b Commonly produced minimum thickness for HSLA sheet
Standard thickness tolerance for Cold-Rolled sheet (all designations)a 3/8" minimum edge distance.
Note 1 Thcikness is measured at any point across the width not less than 3/8" from a side edge.
Note 2 Micrometers used for measurement of thickness shall be constructed with anvils and spindles having minimum diameters of 0.188". The tip of
the spindle shall be flat and the tip of the anvil shall be flat or round with a minimum radius of curvature of 0.10". Micrometers with pointed tips are not
suitable for thickness measurements.
Note 3. The thickness of material <1" wide shall be measured at mid-width.
a Minimum thickness, .021" for HSLA
b The specified thickness range captions apply independent of whether the ordered thickness is stated as a nominal or minimum.
c The tolerances provided in the table are based on minimum thickness (tolerance over, no tolerance under). For nominal thickness; the tolerance is
divided equally over and under.
d Where an ellipsis (...) appear in the table, the requirements have not been defined.
Specified ordered thickness, in. b - Thickness over, in. no tolerance under c
Specified width in. to .014, .014 to .019, over .019 a to over .039 to .057 over .057 to .071 over .071 to .098 over .098 to
excl. incl. .039 incl. incl. incl. incl. .142 incl.
to 15, incl. .002 .004 .006 .008 .010 .010 .010
over 15 to 72, incl. .002 .004 .006 .008 .010 .010 .012
over 72 ... d ... d .006 .008 .010 .012 .014
Restricted thickness tolerance for Cold-Rolled sheet (all designations)a 1" minimum edge distance.
Note 1 Thcikness is measured at any point across the width not less than 1" from a side edge.
Note 2 Micrometers used for measurement of thickness shall be constructed with anvils and spindles having minimum diameters of 0.188". The tip of
the spindle shall be flat and the tip of the anvil shall be flat or round with a minimum radius of curvature of 0.10". Micrometers with pointed tips are not
suitable for thickness measurements.
Note 3. The thickness of material <2" wide shall be measured at mid-width.
a Minimum thickness, .021" for HSLA
b The specified thickness range captions apply independent of whether the ordered thickness is stated as a nominal or minimum.
c The tolerances provided in the table are based on minimum thickness (tolerance over, no tolerance under). For nominal thickness; the tolerance is
divided equally over and under.
d Where an ellipsis (...) appear in the table, the requirements have not been defined.
Specified ordered thickness, in. b - Thickness over, in. no tolerance under c
Specified width in. to .014, .014 to .019, over .019 a to over .039 to .057 over .057 to .071 over .071 to .098 over .098 to
excl. incl. .039 incl. incl. incl. incl. .142 incl.
to 15, incl. .001 .002 .003 .004 .005 .005 .005
over 15 to 72, incl. .001 .002 .003 .004 .005 .005 .006
over 72 ... d ... d .003 .004 .005 .006 .007
FLATNESS TOLERANCES Cold Rolled Sheet (all designations)
Note 1. This table does not apply when product is ordered full hard, to a hardness range, or 'anneal last' (dead soft).
Note 2. This table also applies to lengths cut from coils by the consumer when adequate flattening measures are performed.
a Maximum deviation from a horizontal flat surface.
b Tolerance for SS, and HSLA with specified minimum yield point in excess of 50 ksi. are subject to negotiation.
Flatness tolerance, a in.
Specified Specified width, in. specified Yield
thickness, in. point, min. ksi
under 45 45 to 50 b incl.
to .044, incl to 36 incl 3/8 3/4
over 36 to 60 incl. 5/8 1-1/8
over 60 7/8 1-1/2
over .044 to 36 incl 1/4 3/4
over 36 to 60 incl. 3/8 3/4
over 60 to 72 incl 5/8 1-1/8
over 72 78 1-1/2
SURFACE FINISH OF COLD POLLED SHEET STEEL
Finish refers to the degree of smoothness or luster of the surface as distinct from surface imperfections. The degree of surface roughness is a factor in the
drawing of parts. In the process of stamping sheet steel, the surface finish or appearance may be somewhat altered. It does not necessarily follow that a
completed stamped part will have the same surface appearance as the sheet from which it was made. The production of specific finishes requires special
preparation and control of the roll surfaces employed. The surface finish of cold rolled sheet steel may be described as follows:
Matte Finish - Matte finish is a dull finish, without luster, produced by rolling on rolls which have been roughened by mechanical, chemical or electrical
means to various degrees of surface texture depending upon the application. With some surface preparation matte finish is suitable for decorative
painting. It is not generally recommended for bright plating.
Commercial Bright - Commercial bright finish is a relatively bright finish having a surface texture intermediate between that of matte and luster finish.
With some surface preparation commercial bright finish is suitable for decorative painting or certain plating applications. If the sheets are deformed in
fabrication the surface may roughen to some degree and areas so affected will require surface preparation to restore surface texture to that of the
undeformed areas.
Luster Finish - Luster finish is a smooth bright finish produced by rolling on ground rolls and is suitable for decorative painting or plating with additional
special surface preparation by the consumer. The luster may not be retained after fabrication; therefore, the formed parts will require surface preparation
to make them suitable for bright plating.
BRIEF FACTS
LUSTER - An ultra-smooth finish with higher reflectivity than commercial bright finish produced by rolling on polished rolls. Smoothest, brightest
finish available in cold rolled carbon steel sheet. Creates greater reflectivity and brightness in metallic plating than commercial bright finish.
Profilometer range: approximately 0 to 5 microinches, arithmetic average. Normally shipped oiled. Furnished only in light gauges.
A special surface requirement is also available. This special cold-rolled sheet provides an excellent base for plating after surface removal by the user of at
least 2% of the sheet thickness either in the flat or formed condition. It is used in applications requiring highly finished surfaces (e.g. automotive
bumpers, bumper guards). Limitations on surface texture are not acceptable on orders for Class 2 cold-rolled sheet.
EMBOSSED SHEET & COIL - Embossed steel is cold rolled sheet that has a decorative pattern rolled into the surface. Many patterns are possible.
Practically any design that can be photographed or drawn can be reproduced in embossed steel. Eliminates need to combine steel sheet and strip with
other materials to get special effects such as leather, wood grain, hammered metal finish, many others. Provides strength of steel with enhanced surface
appearance. Saves money compared to laminated plastic, aluminum, wood and soft fabric products. Mar resistant. Depth of pattern embossment is .002
- .012 inch, depending on pattern and steel thickness.
LIGHT MATTE - A uniformly smooth, dull finish produced by rolling on finely textured rolls. Excellent appearance after painting, enameling and
lacquering. Profitometer range: approximately 25 to 45 microinches arithmetic average. Normally shipped oiled. A uniform dull finish produced by
medium texture rolls. Most widely used steel sheet finish. Compared to hot rolled sheet, has greater uniformity in properties, closer dimensional
tolerances and smoother, more uniform surface. Excellent appearance after painting, enameling or lacquering. Profilometer range: approximately 36 to 65
microinches, arithmetic average. Normally shipped oiled.
ROUGH MATTE - A uniformly rough, dull finish produced by roughly textured rolls. Reduced tendency to sticking when batch annealed by the
customer. Although surface roughness is similar to that of hot rolled, pickled-and-oiled sheet, rough matte finish sheet is superior in
uniformity of surface texture and mechanical properties. Profilometer range: approximately 70 to 150 microinches, arithmetic average. Normally shipped
dry.
COMMERCIAL BRIGHT - A smooth, bright, reflective finish produced by rolling on smooth rolls. Primarily used for metallic plating. (Normally
requires grinding and/or buffing before plating.) Enhances the smoothness and brightness of metallic plating,. Profilometer range: approximately 0 to 10
microinches arithmetic average. Normally shipped oiled.
COLD ROLLED SHEET
"Miscellaneous"
PAINTABILITY
Regular matte (standard sheet), finish offers excellent surfaces for adherence of paint and lacquer. Sheet with these surfaces has a mill-applied corrosion-
inhibiting oil which must be removed by solvent or alkaline cleaning or by vapor degreasing. For maximum paint adhesion and corrosion resistance, the
surface should then be prepared by paint pretreatments such as proprietary hot phosphate solutions and a primer containing corrosion-inhibiting
pigment. (If hot phosphate paint pretreatments cannot be used, wash primer or cold phosphate may be used, but some reduction in paint adhesion or
corrosion resistance might result.) Commercial bright and luster finishes are normally used in plating applications. Regular CR Sheet Embossed Sheet
Excellent Excellent - Fabricated parts may be painted with typical spray equipment
WELDABILITY
Cold rolled sheet is readily weldable by either arc or resistance welding. Steels are welded by using fully deoxidized filler metal. Steel with rough matte
finish requires higher welding currents than the other finishes when resistance welding is used.
WIDTH TOLERANCES FOR COLD ROLLED (All designations 0.020" minimum thickness for HSLA)
Specified width, in. Tolerance over specified width,
No tolerance under, in. (narrow coils listed as +/- tolerance)
.
to 6, incl +/- 0.012
over 6 to 9, incl. +/- 0.016
over 9 to 12, incl. +/- 0.032
over 12to 30, incl. 1/8
over 30 to 48, incl. 3/16
over 48 to 60, incl. 1/4
over 60 to 80 incl. 5/16
over 80 3/8
LENGTH TOLERANCES OF COLD ROLLED SHEET (All designations)
Specified lengths, in. Tolerance over specified length not resquared
No tolerance under, in. (narrow coils slit to width up to 12" wide)
.
24 to 60, incl. 1/2
over 60 to 120, incl. 3/4
over 120 to 240, incl. 1
Specified lengths, in. Tolerance over specified length not resquared
No tolerance under, in. (coils over 12" wide)
.
over 12 to 30, incl. 1/8
over 30 to 60, incl. 1/4
over 60 to 96, incl. 1/2
over 96 to 120 incl. 3/4
over 120 to 156, incl. 1
over 156 to 192, incl. 1-1/4
over 192 to 240, incl. 1-1/2
over 240 1-3/4
CAMBER TOLERANCE FOR COLD ROLLED SHEET IN COILS (All designations 0.020 IN. minimum for HSLA for widths to 12")
Note 1 Camber is the greatest deviation of a side edge from a straight line, the measurement being taken on the concave side with a straight edge.
Note 2 This applies to widths produced by slitting from wider sheet.
Width, in. Camber Tolerance
to 12", incl. 1/4 in. in any 8 ft
Cold Rolled carbon sheet steel is manufactured from hot rolled pickled coils by cold reducing to the ordered thickness followed by annealing to
recrystallize the grain structure. The annealed product can be used as-annealed (dead soft) for unexposed applications. For exposed applications the
annealed sheet product is given a skin or temper pass to minimize the phenomenon known as stretcher strains or fluting and to impart suitable surface
texture. Cold rolled sheet steel can be furnished in the full hard (un annealed) condition. Where cold rolled sheet steel is used for fabrication by welding,
chemical composition and mechanical properties should be considered to assure compatibility with the welding process and its effect on altering the
properties.
HOW COLD ROLLED SHEETS ARE MADE
PICKLING
During hot rolling and cooling operations, surface oxides develop which, if not removed, could be rolled into the surface of the sheet during cold
reduction and result in surface defects. Pickling is the use of an acid solution which removes these oxides. During this process other functions are also
performed at the continuous pickling unit:
A. After hot rolled coil ends are cropped, the coils are soundly butt welded together to permit a continuous pickling operation, to build large production
coils for further processing and to satisfy customer's individual coil weight requirements.
B. Edges are side trimmed to meet the ordered width requirement and also make edges uniform for cold reduction and further processing.
C. Inspection of surface.
D. Oil is applied at the exit end of the pickler, to inhibit oxidation of the surface of the deaned steel and to serve as a lubricant for the cold reduction
operation.
COLD REDUCTION
Cold reduction is the sequential rolling of the pickled and oiled coils through tandem mills to achieve desired thickness. The number of mills, or stands, in
tandem generally ranges from 3 to 5. This operation also helps to impart desired surface and shape characteristics. Because of the severe cold reduction,
usually 50% or more, the sheet is now in the "full hard" condition and is usually processed further to develop desired properties such as formability,
flatness and surface texture.
BOX ANNEALING
Cold-reduced steel is usually "full hard" in the as-rolled condition. The grain structure is recrystallized through various heat treating cycles in a box
annealing furnace to put the steel in a suitable condition for shipment as "annealed last" sheets or for further mill processing. Box annealing equipment
consists of: annealing bases on which to place the steel and inner covers to fit over the charge to contain a protective gas atmosphere that prevents
oxidation of the steel and furnaces in which to apply the heat. Fuel of controlled consistency is burned inside the furnace. Primarily radiant heat at
temperatures of 1,000 -1,400 degrees Fahrenheit passes through the protective inner covers and is absorbed by the steel. The entire box-annealing cycle
(heat - cool) takes several days. After box-annealing, the product is in a condition known as "dead soft" or "annealed last". In this state the material is
often used for unexposed parts and is quite ductile, but stretcher straining and fluting tendencies are characteristics of "annealed last" product.
CONTINUOUS ANNEALING
Continuous annealing is a process in which steel coils are unwound and passed through a furnace where they are subjected to a prescribed annealing
cycle under a protective atmosphere. The furnace has both heating and cooling zones and may also contain some type of quenching capability as well as
an over aging section. Temperatures, line speeds and cooling rates are controlled to obtain the desired mechanical properties for the chemistry of the
steel being heat treated. Normally, continuous annealing lines are equipped with entry and exit accumulators that allow coils 10 be welded to one another
so that the annealing proceeds uninterrupted. After annealing, coils often receive further processing such as temper rolling, galvanizing, etc. About 4 to 8
min are required to continuously anneal a coil of steel. Because of the much shorter duration of a continuous -anneal cycle versus a batch-annealed cycle,
higher temperatures are generally necessary. A typical range for most cold-rolled grades is 1,200 to 1,500 degrees Fahrenheit (650 to 815 degrees
Celsius).
TEMPER ROLLING
Temper rolling is a light, carefully controlled cold rolling of»ration that is employed after box annealing to:
1. Improve flatness
2. Produce the final finish or texture
3. Develop required (as shipped) mechanical properties
4. Reduce the tendency of "stretcher strain" or "flute" in forming or drawing.
Product Description
Cold Rolled Sheet - Class 1
Class 1 Is intended (or critical surface quality applications). Surface quality standards assure freedom from minor surface imperfections; typically used
for : exposed surface, surface critical, and is inspected at the mill. Class 1 is intended for exposed applications where surface appearance is of primary
importance. This class will meet requirements for controlled surface texture, surface quality and flatness. It is normally processed by the producer to be
free of stretcher strain and fluting. Subsequent consumer roller levelling immediately before fabrication will minimize strain resulting from aging.
However, when drawing steel special killed is specified roller levelling may not be required. Processed to meet requirements for controlled surface texture
(i.e., regular matte, light matte, commercial bright, luster, embossed), flatness limitations and temper requirements. When cut-length sheet is ordered, the
mill rejects individual sheet having major surface imperfections and repetitive minor surface imperfections. Cut-length sheet may have random minor
surface imperfections. Sheet in coils should be expected to contain major surface imperfections and more minor imperfections than cut-lengths. Coil may
contain welds. APPLICATIONS : Used when surface textures and conditions, flatness and ductility affect quality of the end product.
Cold Rolled Sheet - Class 2
Class 2 Is intended for unexposed or non-critical surface quality applications where surface uniformity and appearance are not the primary
requirements; unexposed surface, non surface critical, not inspected at the mill, and is sometimes Class I rejects. This product is easily painted, welded,
and formed within the limits of the quality designator and the intended application. This product is produced to the flatness standards of Class 1 and is
free of strains and coll breaks. Surface quality standards permit occurrences of minor cosmetic surface imperfections such as pits, slivers, scratches,
slicker breaks, and edge breaks (3/8 inch maximum). When Class 2 is ordered as Annealed Last (Dead Soil), the product can offer improved ductility over
the temper rolled equivalent in certain forming applications. The final operation in manufacturing this product is to pass it through a temper mill or a
recoil line in order to apply oil. This product is subject to strains, fluting and coil breaks. Restrictions on surface finish or standard flatness tolerances do
not apply. Surface quality standards are the same as for a tempered product.
Class 2 is generally intended for unexposed applications only. It is normally produced without temper rolling, but may be lightly rolled in the process of
oiling or rewinding. This class can be expected to have coil breaks, fluffing and stretcher straining. Standard tolerances for flatness and surface texture are
not applicable. In addition, surface imperfections are more prevalent than with Class 1 because steel applications, processing procedures and inspection
standards are less stringent.
Class 2 • Tempered Brief Facts:
• All purpose sheet where surface appearance is not of primary importance.
• Limitations on surface texture or surface roughness are not applicable.
• Processed to meet flatness limitations of class 1.
• Freedom from straining, crossbreaks and pinchers.
• Minor surface imperfections such as pits, scratches, sticker breaks, roll marks may be expected.
• Major surface imperfections such as holes and loose slivers may be present in coils.
• Very little Class 2 cold rolled non-tempered sold in this country.
• Most product Class 2 is tempered that is sold in this country.
• Finest ductile steel is (especially drawing quality) continuous cast.
APPLICATIONS: Used for unexposed parts and exposed parts where surface appearance Is not of primary Importance. Not suitable for continuous
coll painting.
Class 2 - Non-Tempered Brief Facts:
• Economy sheet where surface appearance is not of primary importance.
• Limitations on surface texture or surface roughness and: tempers are not applicable.
• Subject to stretcher strains and fluting.
• Will normally be within twice the standard flatness tolerances in cut lengths and after removal of coil set in coils.
• Coils and cut lengths' must be expected to contain minor surface imperfections such as pits, scratches, sticker breaks, edge breaks, pinchers, cross
breaks, roll marks and other minor surface imperfections.
• Major surface imperfections such as holes and loose slivers may be present in coils.
APPLICATIONS: Used when surface texture or condition Is not Important to appearance of finished product and maximum formabllity is desired. Not
suitable for continuous coil painting.
COLD ROLLED FINISHES
ROUGH MATTE (#4) -70 to 150 Microinch Finish
REGULAR MATTE (#6) - 30 to 60 Microinch Finish
LIGHT MATTE (#7) - 20 to 45 Microinch Finish
DUST BRIGHT (#9) - 20 max. Microinch Finish
COMMERCIAL BRIGHT (#10) - 10 max. Microinch Finish
COLD ROLLED SHEET & COIL
PRODUCT CLASSIFICATION BY SIZE
Thickness (inches)
.250 and .249 to .014 and
Width (inches) thicker .014 thinner
Thru l2 Bar Strip (1,2) Strip(1)
2-12 Bar Strip (3) Strip
Over 12 - 23 15/16 Strip (2) Strip (2) Strip
Over 12 Sheet (4) Sheet (4) Black Plate
(1)Flat Wire: When the width is greater than the thickness with a maximum width of 1/2" and cross-sectional area not exceeding .05 square inches and
the material has rolled or prepared edges.
(2)CR Strip: When a finish or temper or ecge as numerically identified in ASTM A-W9, is specified, or when single strand rolling is specified on widths
over 1/2".
(3)CR Slit Sheet: Cold Rolled Sheet coils in widths 2" through 12", slit from multiple strand coils and furnished to slit sheet thickness and dimensional
tolerances.
(4)CR Sheet: When none of the features of Note (2) above are specified or required.
COLD ROLLED SHEET & COIL INDUSTRY DESIGNATIONS/QUALITY SPECIFICATIONS
AISI - SAE Grades: (Standard) Chemical limits
Steel designations Carbon Manganese
1006 0.08 max. 0.45 max.
1008 0.10 max. 0.45 max.
1009 0.15 max. 0.60 max.
1010 0.08 - 0.13 0.30 - 0.60
1012 0.10 - 0.15 0.30 - 0.60
1015 0.12 - 0.18 0.30 - 0.60
Specified Chemistry
Customer can specify their carbon and manganese ranges - as well as limiting phosphorus...copper...sulfur...and other additions. (These chemistry
restrictions require special mill ordering practices.)
ASTM QUALITY SPECIFICATIONS
A-1008 Combined specification for the old A-366 CR Commercial Steel, A-607 High-Strength with Columbium or Vanadium, A-611 Structural Steel, A-
620 Drawing Steel SK, A-963 Deep Drawing Steel, A-969 Extra Deep Drawing Steel
A-794 CR Commercial Steel with Carbon .16/.25
A-606 Improved Corrosion Resistance
Full Hard and Intermediate Tempers
It is conventional to determine the surface hardness of Cold Rolled Carbon Steel Sheets as a "Rockwell Hardness Number" derived from the measured
depth of impression of a carbide ball on a test specimen. The Rockwell "T" scale is commonly used (its values can be converted to other scales such as
15-T and 30-T). The lower the Rockwell value, the softer the steel.
Full Hard
A very stiff cold rolled sheet. Rockwell hardness, B scale: 84 (minimum]}.
Half-Hard
A medium stiff cold rolled sheet. Rockwell hardness, B scale: 70-85 at tiime of shipment. (Aging may result in a slightly greater hardness when tested at
a later time.)
Quarter-Hard
A moderately stiff cold rolled sheet. Rockwell hardness, B scale: 60-75 at time of shipment. (Aging may result in a slightly greater hardness when
tested at a later time.)
'When a cold rolled carbon steel sheet is specified to hardness limits, it is necessary to employ restricted chemical composition limits, special mill
processing practices, or both. Cold-rolled sheets specified as full hard on-intermediate tempers are not subject to any definite forming requirements or to
flatness tolerances. For cold rolled sheets specified to hardness ranges other than those shown for quarter-hard and half-hard tempers, the specified
Rockwell B range is customarily 15 points.
COLD ROLLED PRODUCT DESCRIPTIONS Cold Rolled Sheet Steel is available in 33 grades/descriptions in ASTM A1008, 2 grades/descriptions in
ASTM A606, and 7 typical grades/descriptions in ASTM A794.
C%, max. Mn% max.
Commercial Steel Type A ..lO% .60 Stabilized at producers option
Commercial Steel Type B . 02/.15% .60
Commercial Steel Type C .08 .60 P .100% max. Stabilized at producers option
Drawing Steel Type A .08 .50
Drawing Steel Type B .02/.08 .50
Deep Drawing Steel .06 .50 Stabilized at producers option
Extra Deep Drawing Steel .02 .40 Stabilized
Structural Steel Carbon Manganese
Structural Steel Carbon Manganese V, Nb(Cb), Ti
Structural Steel Strain hardening
Structural Steel Bake hardening
Ordered to specified mechanical properties. The choice of one of these descriptions can be made in one or more of the following ways:
1. Examination of a drawing.
2. Examination of a completed part, plus experienced judgment of ductility requirements.
3. Previous history of similar parts.
Usually, sheet is ordered by specifying only the description - CS, DDS, EDDS, SS, HSLA, SHS, or BHS. On occasion, a customer may find it necessary
to specify cold rolled sheet to both chemical composition and mechanical properties. When this situation occurs, the compatibility of required
properties and steel composition must be determined.
COMMERCIAL STEEL (CS)
Commercial steels are less ductile than drawing steels, and they can be expected to show wider variations in mechanical properties and chemical
composition. CS sheets are also subject to some loss of ductility with time. Commercial steels are ordinarily produced to a low carbon level and are
suitable for exposed parts requiring a good surface finish. The sheets are normally produced with a matte finish for the application of various organic
finishes, such as paints, enamels and lacquers. If the sheets are to be essentially free from stretcher strains during fabrication, they should be roller
leveled just before the forming operation.
DRAWING STEEL (DS, DDS, EDDS)
Drawing steels are more ductile and more uniform in chemical composition than commercial steels. Drawing steels are manufactured to have good
uniform drawing properties for use in fabricating parts having sever deformations. Drawing steels are not normally specified to a chemical composition
and are generally furnished for use in fabricating an identified part with severe drawing and/or forming. The customer normally furnishes information to
the producer on the individual requirements of the identified part. Drawing steels are usually produced with a matte finish. Neither commercial bright
nor luster finish are compatible with severe drawing requirement to which these grades are usually subjected. DDS & EDDS should be specified where
the formed material is to be essentially free of such surface disturbances as stretcher strains or fluting without the need of prior roller leveling.
STRUCTURAL STEELS (SS, HSLA, SHS, BHS)
Produced when mechanical properties are required, usually to an ASTM or customer specification.
COLD ROLLED TYPICAL MECHANICAL PROPERTIES
Yield Strength KSI %E (2") R Bar N value
Designation
CS Type A, B & C : 20/40 30 ---- ----
DS Type A & B 22/35 36 1.3/1.7 .17/.22
DDS 17/29 38 1.4/1.8 .20/.25
EDDS 15/25 40 1.7/2.1 .23/27
COLD ROLLED SHEET & COIL HIGH STRENGTH STEELS
High Strength Steels are used for weight reduction, increased strength / durability, and cost reduction. These grades are used in place of conventional low
carbon sheet steels. Switching to a high strength steel when designing or redesigning a product can bring significant gains to a customer.
Advantages include:
• Less component weight through reduced section thickness
• Lower costs
• Greater strength.
• And, in some cases, better atmospheric corrosion resistance
Interest in high-strength steels has further increased as more of these grades have been developed with fabricating and welding characteristics closer to
those of conventional sheet steels. For an end user to gain these important advantages, high strength steels must be selected carefully and designed
properly into the product. The steel industry groups its high strength steels by yield strength. Having a variety of steels at each strength level enables
users to select the most efficient and economical product for a given application.
Properties
When a component design calls for a certain minimum yield strength, a designer naturally will want to use the lowest priced steel available with that
strength. But properties other than yield strength should be considered. These properties might include formability, weld ability, tensile strength, fatigue
strength, stiffness, (modulus), impact resistance and corrosion resistance. These properties, as well as cost, vary among the steels available at each
strength level. The steel industry can provide technical assistance in selecting the high-strength steel that has the right combination of properties for
your application.
Sheet products are classified as High Strength when the minimum specified yield strength is 35,000 psi or greater. High strength sheets are sold to
strength levels regardless of the chemical composition. All the High Strength products are identified by a designator system. Use of the designator
permits a more accurate appraisal of customers' needs and product performance requirements. High Strength grades are used where higher strength or
weight reduction is required. Principle applications are for structural, automotive and agricultural applications.
Availability
High Strength Sheet is available in the approximate size range of Carbon Sheet. The increased work load on the rolling mills, coupled with a minimum
thickness reduction causes some limitations on minimum thicknesses and maximum widths.
HIGH STRENGTH LOW ALLOY SHEET STEEL
High strength low alloy sheet steel represents a group of steels having higher strength values, improved formability, weld ability, and/or atmospheric
corrosion resistance than normally obtained from conventional carbon structural steels. These desirable properties are obtained through selected chemical
composition and controlled mill processing. High strength low alloy steels lend themselves to applications where weight reduction* is a major factor. In
some cases this can be done without changing the application. In other cases anything from a minor to a major redesign of the components may be
necessary. High strength low alloy steel is produced -with emphasis on mechanical properties in the as rolled condition.
The yield point and tensile strength requirements most often specified as minimum vary within the following range:
• Yield Point .................... 35,000 psi to 80,000 psi
• Tensile Strength ............ 55,000 psi to 90,000 psi
These high strength low allow sheet steels utilize alloy additions and mill processing techniques to obtain unique properties within the full range of
strength levels given, whereas conventional carbon structural quality sheet steel (without alloying) is available only in the lower strength levels of the
ranges listed.
TYPES
High strength low alloy sheet steel is not available in the four principle qualities commonly used for other sheet steel products (i.e. CS, DS, DDS, and
EDDS ). However, this product is available in the following types:
• Conventional
• Improved Atmospheric Corrosion Resistance
• Improved Formability
Because high strength low alloy sheet steels are characterized by their mechanical properties , the strength and forming requirements may not be
compatible. Care must be taken in designing parts, tooling and fabrication processes to maximize utilization of the high strength low alloy sheet steels. It
is important that the purchaser furnish information to the producer relating the individual requirements of an identified part. Also; it is highly desirable
to observe the fabricating practices, or, at least provide a detailed description of the operations. The wide variety of chemical compositions provides a
wide variety of forming characteristics. Certain compositions are suited for the more demanding forming applications while others are designed primarily
to provide superior atmospheric corrosion resistance or weld ability. Therefore, it is recommended that the purchaser consult with the producer to
determine that the correct type of high strength low alloy sheet steel will be specified.
The types of high strength low alloy sheet steel may be specified to the following ASTM A1008 specification. This ASTM standard includes all the
individual chemical compositions and strength levels produced.
.
Conventional Type (old ASTM A607 "STEEL SHEET AND STRIP, HOT-ROLLED AND COLD-ROLLED. HIGH-STRENGTH, LOW ALLOY
COLUMBIUM AND/OR VANADIUM") This type is produced to various strength levels where atmospheric corrosion resistance and maximum
formability are not a requirement.
NOT INCLUDED IN ASTM A1008 - Improved Atmospheric Corrosion Resistance Type - ASTM A606 "STEEL SHEET AND STRIP, HOT-
ROLLED AND COLD-ROLLED, HIGH-STRENGTH, LOW-ALLOY WITH IMPROVED CORROSION RESISTANCE". This type is produced to
45,000 psi or 50,000 psi minimum yield points. To enhance atmospheric corrosion resistance two types of steel are available. Type 2 having corrosion
resistance of at least two times that of plain carbon steel is usually produced with a copper addition. Type 4 having corrosion resistance of at least four
times that of plain carbon steel is produced with a variety of alloying elements to achieve the desired effect. The consumer should consult the producer
for specific atmospheric corrosion resistance data.
Improved Formability Type (OLD ASTM A715 "STEEL SHEET AND STRIP, HOT-ROLLED, HIGH-STRENGTH, LOW-ALLOY, WITH
IMPROVED FORMABILITY"). This type is produced with special forming properties to various strength levels where maximum formability is
required. It is normally supplied with sulfide inclusion control. This type is generally furnished for use in fabricating an identified part too difficult for
the fabricating properties of the two types listed.
DIMENSIONAL CLASSIFICATION FOR COLD ROLLED CARBON, HIGH STRENGTH LOW ALLOY AND ALLOY SHEET STEEL
Thickness, inch
Width, inch
Carbon and Carbon Carbon HSLA Alloy
Alloy Strip Black Plate Sheet Sheet Sheet
Thru 2 Thru 0.2499
2 - 12 Thru 0.2499 .0142 - .01821 a .0195 - .0821 b
Over 12 - 23 15/16 Thru 0.2499 under .014 .0142 & thicker .0284 & thicker thru .2299
23 15/16 - 48 under .014 .0142 & thicker .0284 & thicker thru .1799
Over 48 .0142 & thicker .0284 & thicker
a Produced by slitting from wider sheet
b Commonly produced minimum thickness for HSLA sheet
Standard thickness tolerance for Cold-Rolled sheet (all designations)a 3/8" minimum edge distance.
Note 1 Thcikness is measured at any point across the width not less than 3/8" from a side edge.
Note 2 Micrometers used for measurement of thickness shall be constructed with anvils and spindles having minimum diameters of 0.188". The tip of
the spindle shall be flat and the tip of the anvil shall be flat or round with a minimum radius of curvature of 0.10". Micrometers with pointed tips are not
suitable for thickness measurements.
Note 3. The thickness of material <1" wide shall be measured at mid-width.
a Minimum thickness, .021" for HSLA
b The specified thickness range captions apply independent of whether the ordered thickness is stated as a nominal or minimum.
c The tolerances provided in the table are based on minimum thickness (tolerance over, no tolerance under). For nominal thickness; the tolerance is
divided equally over and under.
d Where an ellipsis (...) appear in the table, the requirements have not been defined.
Specified ordered thickness, in. b - Thickness over, in. no tolerance under c
Specified width in. to .014, .014 to .019, over .019 a to over .039 to .057 over .057 to .071 over .071 to .098 over .098 to
excl. incl. .039 incl. incl. incl. incl. .142 incl.
to 15, incl. .002 .004 .006 .008 .010 .010 .010
over 15 to 72, incl. .002 .004 .006 .008 .010 .010 .012
over 72 ... d ... d .006 .008 .010 .012 .014
Restricted thickness tolerance for Cold-Rolled sheet (all designations)a 1" minimum edge distance.
Note 1 Thcikness is measured at any point across the width not less than 1" from a side edge.
Note 2 Micrometers used for measurement of thickness shall be constructed with anvils and spindles having minimum diameters of 0.188". The tip of
the spindle shall be flat and the tip of the anvil shall be flat or round with a minimum radius of curvature of 0.10". Micrometers with pointed tips are not
suitable for thickness measurements.
Note 3. The thickness of material <2" wide shall be measured at mid-width.
a Minimum thickness, .021" for HSLA
b The specified thickness range captions apply independent of whether the ordered thickness is stated as a nominal or minimum.
c The tolerances provided in the table are based on minimum thickness (tolerance over, no tolerance under). For nominal thickness; the tolerance is
divided equally over and under.
d Where an ellipsis (...) appear in the table, the requirements have not been defined.
Specified ordered thickness, in. b - Thickness over, in. no tolerance under c
Specified width in. to .014, .014 to .019, over .019 a to over .039 to .057 over .057 to .071 over .071 to .098 over .098 to
excl. incl. .039 incl. incl. incl. incl. .142 incl.
to 15, incl. .001 .002 .003 .004 .005 .005 .005
over 15 to 72, incl. .001 .002 .003 .004 .005 .005 .006
over 72 ... d ... d .003 .004 .005 .006 .007
FLATNESS TOLERANCES Cold Rolled Sheet (all designations)
Note 1. This table does not apply when product is ordered full hard, to a hardness range, or 'anneal last' (dead soft).
Note 2. This table also applies to lengths cut from coils by the consumer when adequate flattening measures are performed.
a Maximum deviation from a horizontal flat surface.
b Tolerance for SS, and HSLA with specified minimum yield point in excess of 50 ksi. are subject to negotiation.
Flatness tolerance, a in.
Specified Specified width, in. specified Yield
thickness, in. point, min. ksi
under 45 45 to 50 b incl.
to .044, incl to 36 incl 3/8 3/4
over 36 to 60 incl. 5/8 1-1/8
over 60 7/8 1-1/2
over .044 to 36 incl 1/4 3/4
over 36 to 60 incl. 3/8 3/4
over 60 to 72 incl 5/8 1-1/8
over 72 78 1-1/2
SURFACE FINISH OF COLD POLLED SHEET STEEL
Finish refers to the degree of smoothness or luster of the surface as distinct from surface imperfections. The degree of surface roughness is a factor in the
drawing of parts. In the process of stamping sheet steel, the surface finish or appearance may be somewhat altered. It does not necessarily follow that a
completed stamped part will have the same surface appearance as the sheet from which it was made. The production of specific finishes requires special
preparation and control of the roll surfaces employed. The surface finish of cold rolled sheet steel may be described as follows:
Matte Finish - Matte finish is a dull finish, without luster, produced by rolling on rolls which have been roughened by mechanical, chemical or electrical
means to various degrees of surface texture depending upon the application. With some surface preparation matte finish is suitable for decorative
painting. It is not generally recommended for bright plating.
Commercial Bright - Commercial bright finish is a relatively bright finish having a surface texture intermediate between that of matte and luster finish.
With some surface preparation commercial bright finish is suitable for decorative painting or certain plating applications. If the sheets are deformed in
fabrication the surface may roughen to some degree and areas so affected will require surface preparation to restore surface texture to that of the
undeformed areas.
Luster Finish - Luster finish is a smooth bright finish produced by rolling on ground rolls and is suitable for decorative painting or plating with additional
special surface preparation by the consumer. The luster may not be retained after fabrication; therefore, the formed parts will require surface preparation
to make them suitable for bright plating.
BRIEF FACTS
LUSTER - An ultra-smooth finish with higher reflectivity than commercial bright finish produced by rolling on polished rolls. Smoothest, brightest
finish available in cold rolled carbon steel sheet. Creates greater reflectivity and brightness in metallic plating than commercial bright finish.
Profilometer range: approximately 0 to 5 microinches, arithmetic average. Normally shipped oiled. Furnished only in light gauges.
A special surface requirement is also available. This special cold-rolled sheet provides an excellent base for plating after surface removal by the user of at
least 2% of the sheet thickness either in the flat or formed condition. It is used in applications requiring highly finished surfaces (e.g. automotive
bumpers, bumper guards). Limitations on surface texture are not acceptable on orders for Class 2 cold-rolled sheet.
EMBOSSED SHEET & COIL - Embossed steel is cold rolled sheet that has a decorative pattern rolled into the surface. Many patterns are possible.
Practically any design that can be photographed or drawn can be reproduced in embossed steel. Eliminates need to combine steel sheet and strip with
other materials to get special effects such as leather, wood grain, hammered metal finish, many others. Provides strength of steel with enhanced surface
appearance. Saves money compared to laminated plastic, aluminum, wood and soft fabric products. Mar resistant. Depth of pattern embossment is .002
- .012 inch, depending on pattern and steel thickness.
LIGHT MATTE - A uniformly smooth, dull finish produced by rolling on finely textured rolls. Excellent appearance after painting, enameling and
lacquering. Profitometer range: approximately 25 to 45 microinches arithmetic average. Normally shipped oiled. A uniform dull finish produced by
medium texture rolls. Most widely used steel sheet finish. Compared to hot rolled sheet, has greater uniformity in properties, closer dimensional
tolerances and smoother, more uniform surface. Excellent appearance after painting, enameling or lacquering. Profilometer range: approximately 36 to 65
microinches, arithmetic average. Normally shipped oiled.
ROUGH MATTE - A uniformly rough, dull finish produced by roughly textured rolls. Reduced tendency to sticking when batch annealed by the
customer. Although surface roughness is similar to that of hot rolled, pickled-and-oiled sheet, rough matte finish sheet is superior in
uniformity of surface texture and mechanical properties. Profilometer range: approximately 70 to 150 microinches, arithmetic average. Normally shipped
dry.
COMMERCIAL BRIGHT - A smooth, bright, reflective finish produced by rolling on smooth rolls. Primarily used for metallic plating. (Normally
requires grinding and/or buffing before plating.) Enhances the smoothness and brightness of metallic plating,. Profilometer range: approximately 0 to 10
microinches arithmetic average. Normally shipped oiled.
COLD ROLLED SHEET
"Miscellaneous"
PAINTABILITY
Regular matte (standard sheet), finish offers excellent surfaces for adherence of paint and lacquer. Sheet with these surfaces has a mill-applied corrosion-
inhibiting oil which must be removed by solvent or alkaline cleaning or by vapor degreasing. For maximum paint adhesion and corrosion resistance, the
surface should then be prepared by paint pretreatments such as proprietary hot phosphate solutions and a primer containing corrosion-inhibiting
pigment. (If hot phosphate paint pretreatments cannot be used, wash primer or cold phosphate may be used, but some reduction in paint adhesion or
corrosion resistance might result.) Commercial bright and luster finishes are normally used in plating applications. Regular CR Sheet Embossed Sheet
Excellent Excellent - Fabricated parts may be painted with typical spray equipment
WELDABILITY
Cold rolled sheet is readily weldable by either arc or resistance welding. Steels are welded by using fully deoxidized filler metal. Steel with rough matte
finish requires higher welding currents than the other finishes when resistance welding is used.
WIDTH TOLERANCES FOR COLD ROLLED (All designations 0.020" minimum thickness for HSLA)
Specified width, in. Tolerance over specified width,
No tolerance under, in. (narrow coils listed as +/- tolerance)
.
to 6, incl +/- 0.012
over 6 to 9, incl. +/- 0.016
over 9 to 12, incl. +/- 0.032
over 12to 30, incl. 1/8
over 30 to 48, incl. 3/16
over 48 to 60, incl. 1/4
over 60 to 80 incl. 5/16
over 80 3/8
LENGTH TOLERANCES OF COLD ROLLED SHEET (All designations)
Specified lengths, in. Tolerance over specified length not resquared
No tolerance under, in. (narrow coils slit to width up to 12" wide)
.
24 to 60, incl. 1/2
over 60 to 120, incl. 3/4
over 120 to 240, incl. 1
Specified lengths, in. Tolerance over specified length not resquared
No tolerance under, in. (coils over 12" wide)
.
over 12 to 30, incl. 1/8
over 30 to 60, incl. 1/4
over 60 to 96, incl. 1/2
over 96 to 120 incl. 3/4
over 120 to 156, incl. 1
over 156 to 192, incl. 1-1/4
over 192 to 240, incl. 1-1/2
over 240 1-3/4
CAMBER TOLERANCE FOR COLD ROLLED SHEET IN COILS (All designations 0.020 IN. minimum for HSLA for widths to 12")
Note 1 Camber is the greatest deviation of a side edge from a straight line, the measurement being taken on the concave side with a straight edge.
Note 2 This applies to widths produced by slitting from wider sheet.
Width, in. Camber Tolerance
to 12", incl. 1/4 in. in any 8 ft
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