ASTM A657/A657M-18(2024)
(Specification)Standard Specification for Tin Mill Products, Black Plate Electrolytic Chromium-Coated, Single and Double Reduced
Standard Specification for Tin Mill Products, Black Plate Electrolytic Chromium-Coated, Single and Double Reduced
ABSTRACT
This specification covers single- and double-reduced tin mill black plate electrolytically coated with chromium and chromium oxide. The steel shall be furnished in coils and cut lengths for use in manufacture of cans, closures, crowns, and other products. The weights of the total coating which is made up of chromium metal and chromium oxides shall be determined. Single-reduced base steels shall be produced with ground roll finishes (type 7B-A for smooth finish containing fine grit lines and type 7C-A for smooth finish with grit lines), and shot-blasted and/or textured roll finishes (type 5C-A for shot-blasted finish for general applications and type 5D-A for special applications). Double-reduced base steels shall be produced only with ground roll finishes of type 7C-A. The steels shall be furnished with extremely thin oil film on both surfaces.
SCOPE
1.1 This specification covers single- and double-reduced tin mill black plate electrolytically coated with chromium and chromium oxide. The steel is furnished in coils and cut lengths for use in the manufacture of cans, closures, crowns, and other products.
1.2 This specification is applicable to orders in either inch-pound units (as A657) which is supplied in thicknesses from 0.0050 to 0.0149 in. or in SI units [as A657M] which is supplied in thicknesses from 0.127 to 0.378 mm.
1.3 The values stated in either inch-pound or SI units are to be regarded as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents. Therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: A657/A657M − 18 (Reapproved 2024)
Standard Specification for
Tin Mill Products, Black Plate Electrolytic Chromium-
Coated, Single and Double Reduced
This standard is issued under the fixed designation A657/A657M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* A623M Specification for Tin Mill Products, General Re-
quirements [Metric]
1.1 This specification covers single- and double-reduced tin
A700 Guide for Packaging, Marking, and Loading Methods
mill black plate electrolytically coated with chromium and
for Steel Products for Shipment
chromium oxide. The steel is furnished in coils and cut lengths
D1125 Test Methods for Electrical Conductivity and Resis-
for use in the manufacture of cans, closures, crowns, and other
tivity of Water
products.
1.2 This specification is applicable to orders in either 3. Ordering Information
inch-pound units (as A657) which is supplied in thicknesses
3.1 Orders for product under this specification shall include
from 0.0050 to 0.0149 in. or in SI units [as A657M] which is
the following information, as required and applicable, to
supplied in thicknesses from 0.127 to 0.378 mm.
adequately describe the desired product:
1.3 The values stated in either inch-pound or SI units are to 3.1.1 Name of product (include whether single- or double-
be regarded as standard. Within the text, the SI units are shown reduced),
in brackets. The values stated in each system are not exact 3.1.2 Thickness (must be consistent with intended
equivalents. Therefore, each system must be used indepen- application),
dently of the other. Combining values from the two systems 3.1.3 Oiling (Section 6),
may result in nonconformance with this specification. 3.1.4 Steel type (MR, L, etc.),
3.1.5 Temper designation (T-3, T-4, etc. for single-reduced)
1.4 This standard does not purport to address all of the
or mechanical designation (DR-8, DR-9, etc., double-reduced),
safety concerns, if any, associated with its use. It is the
3.1.6 Surface finish (7B, 7C, etc.).
responsibility of the user of this standard to establish appro-
3.1.7 Coil width or cut size,
priate safety, health, and environmental practices and deter-
3.1.8 Rolling direction must be specified on cut sizes and
mine the applicability of regulatory limitations prior to use.
should be indicated by underlining the slit (rolling width)
1.5 This international standard was developed in accor-
dimension,
dance with internationally recognized principles on standard-
3.1.9 On coils, specify minimum or range of acceptable
ization established in the Decision on Principles for the
inside diameters. The standard inside diameter is approxi-
Development of International Standards, Guides and Recom-
mately 16 in. if ordered as Specification A657 [410 mm if
mendations issued by the World Trade Organization Technical
ordered as Specification A657M]. Coils should be specified to
Barriers to Trade (TBT) Committee.
a maximum coil weight if ordered as Specification A657 [mass
2. Referenced Documents if ordered as Specification A657M], or maximum outside
2 diameter, or both.
2.1 ASTM Standards:
3.1.10 Packaging,
A623 Specification for Tin Mill Products, General Require-
3.1.11 Special requirements where applicable, and,
ments
3.1.12 ASTM specification designation and year of issue.
NOTE 1—A typical ordering description for coils is as follows: 1250
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
base boxes, single reduced, black plate electrolytic chromium coated,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
BSO, (0.0093 in.) MR, T-3 BA, 35 ⁄8 in. by coil, 16 in. inside diameter, 59
A01.20 on Tin Mill Products.
in. maximum outside diameter, 25 000 lb maximum coil weight, for
Current edition approved March 1, 2024. Published March 2024. Originally
regular crowns in accordance with Specification A657/A657M - XX. [250
approved in 1972. Last previous edition approved in 2018 as A657/A657M – 18.
SITAs, single reduced, black plate electrolytic chromium coated, BSO,
DOI: 10.1520/A0657_A0657M-18R24.
0.235 mm thickness, MR, T-3 BA, 900 mm by coil, 410 mm inside
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
diameter, 1500 mm maximum outside diameter, 11 500 kg maximum coil
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on mass for regular crowns in accordance with Specification A657/
the ASTM website. A657M - XX].
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A657/A657M − 18 (2024)
NOTE 2—A typical ordering description of cut sizes is as follows: 1000
specification for metallic chromium and chromium oxide
base boxes, double reduced black plated electrolytic chromium coated,
weights [mass] on a specification of electrolytic chromium-
BSO, 0.0061 in., MR, DR8 CA, 31 by 32 in., for cap closures in
coated steel in cut sizes, use the following procedure:
accordance with Specification A657/A657M - XX. [200 SITAs, double
4.2.2.1 Take one sheet at random from each 50 packages, or
reduced, black plate electrolytic chromium coated, BSO, 0.155 mm
part thereof, with a minimum of three different sample sheets,
thickness, MR, DR8 CA, 788 by 813 mm, cap closures in accordance with
Specification A657/A657M - XX].
each taken from different bundles from any one item of a
NOTE 3—The production of coils does not afford the same opportunity
specific shipment. Spot test each sample at three positions
for inspection, grading, and sorting as does the production of cut sizes.
across the rolling direction of the sheet (edge, center, edge).
Accordingly, appropriate processing and quality-control procedures are
Spot samples are customarily disks or squares, each of 4 in.
required by the purchaser to obtain optimum utilization of the material.
Cut sizes are line inspected visually and mechanically during production. [25.8 cm ] in area. In order to secure representative samples,
Sheets having surface imperfections that will not interfere with their
take edge specimens so that the outer edge of the sample is at
utilization are included.
least 1 in. [25 mm] from either edge of the sheet. The average
NOTE 4—Tin mill products are supplied on an area basis expressed in
value of all spot tests on all sheets tested represents the average
base boxes. In coils, the number of base boxes is computed from the
coating-weight (mass) test value.
measured length and the specified width. In cut sizes, the number of base
boxes is computed from the specified length and width dimensions and
4.3 Determination of Chromium Coating Weights
sheet count. For calculating weight, the density of steel for tin mill
3 [Masses]—Typical method for determining metallic chromium
products is 0.2836 lb/in. [Tin mill products are supplied on an area basis
and chromium oxide weights [masses] for electrolytic
expressed in SITAs. In coils, the number of SITAs is computed from the
measured length and the specified width. In cut sizes, the number of SITAs chromium-coated steel is described in Annex A1, Annex A2,
is computed from the specified length and width dimensions and sheet
Annex A3, and Fig. A1.1 and Fig. A3.1.
count. For calculating mass, the density of steel for tin mill products is
7850 kg/m ].
5. Surface Appearance and Finish
5.1 Single-Reduced Base Metal Finish—Single-reduced
4. Chromium Coating Weights [Masses]
electrolytic chromium coated steel is produced with ground roll
4.1 Total Coating is made up of chromium metal and
finishes and shot-blasted roll finishes as follows:
chromium oxides. These are determined separately.
5.1.1 Ground Roll Finishes:
4.1.1 Metallic Chromium is expressed as milligrams of
5.1.1.1 7B—A smooth finish that may contain fine grit lines.
chromium metal per square foot [milligrams of chromium per
This finish is specified for special applications.
square metre] on each side of the sheet or strip.
5.1.1.2 7C—A smooth finish with grit lines. The surface
Nominal Average Min Average Max
roughness will range from 10 to 25 μin. Ra [0.254 to 0.635 μm
2 2 2 2 2 2
mg/ft [mg/m ] mg/ft [mg/m ] mg/ft [mg/m ]
Ra]. This is the standard finish for tin mill products.
5 [54] 3 [32] 13 [140]
5.1.2 Blasted and/or Otherwise Textured Roll Finishes:
4.1.2 Chromium Oxide is expressed as milligrams of chro-
5.1.2.1 5C—A shot-blasted finish (SBF) for general appli-
mium in the oxide per square foot [milligrams of chromium per
cations. The surface roughness will range from 30 to 60 μin. Ra
square metre] as shipped on each side of the sheet or strip.
[0.760 to 1.52 μm Ra].
Average Min, Average Max,
5.1.2.2 5D—A shot-blasted finish for special applications.
2 2 2 2
mg/ft [mg/m ] mg/ft [mg/m ]
0.7 [8] 2.5 [27]
5.2 Double-Reduced Base Metal Finish—Double-reduced
electrolytic chromium-coated steel is produced only with
4.2 Sampling for Chromium Coating Weights [Masses]:
4.2.1 Coils—When the purchaser wishes to make tests to ground-roll finishes.
5.2.1 Ground Roll Finishes:
ascertain compliance with the requirements of this specifica-
tion for metallic chromium and chromium oxide weights 5.2.1.1 7C—A smooth finish with grit lines. The surface
roughness will range from 6 to 25 μin. Ra [0.152 to 0.635 μm
[masses] on a lot of any specific item of electrolytic chromium-
coated steel in coils, use the following procedure: Ra]. This is the standard finish for tin mill products.
4.2.1.1 Take one test strip at random from a representative
6. Oiling
section of each coil across its width. Select a minimum of three
test strips, each taken from different coils from any one item of 6.1 Electrolytic Chromium-Coated Steel is furnished with
a specific lot. Spot test each test strip at three positions (edge, an extremely thin oil film on both surfaces to minimize
center, edge) across the rolling direction of the strip. Spot abrasion in shearing, coiling or uncoiling, shipping, and
samples are customarily disks or squares, each of 4 in. [25.8 handling. Acetyl tributylcitrate (ATBC), butyl stearate (BSO),
cm ] in area. In order to secure representative samples, take or dioctyl (di(2-ethylhexyl) sebacate) (DOS) is used. Surface
samples so that the outer edge of the sample is at least 1 in. [25 active agents such as glycerol monooleate may be incorporated
mm] from either edge of the test strip. The average value of all
into the oil film. Oil film other than normal should be
spot tests on all test strips represents the average coating- negotiated with the producer. The oil film is not a drawing
weight [mass] test value.
lubricant.
4.2.1.2 From one- or two-coil lots, sample each coil. A 6.1.1 Unless indicated by the purchaser, the special oiling
minimum of three randomly selected test strips shall represent
treatment will be left to the discretion of the plate supplier.
the lot. 6.1.2 Weight [mass] of oil film as applied by the plate
4.2.2 Cut Lengths—When the purchaser wishes to make supplier normally ranges from approximately 0.10 g/base box
tests to ascertain compliance with the requirements of this to 0.40 g/base box [0.50 to 200 g/SITA (5 to 20 mg/m )]. The
A657/A657M − 18 (2024)
specified range is the total of both surfaces. Specific aim ranges having surface imperfections that will not interfere with their
required for particular end uses and handling practices may be utilization are included.
furnished as agreed upon by the purchaser and supplier.
8. General Requirements for Delivery
7. Workmanship and Quality Level Requirements
8.1 Product furnished under this specification shall conform
7.1 The production of coils does not afford the same
to the applicable requirements of the latest edition of Specifi-
opportunity for inspection, grading, and sorting as does the
cation A623 [A623M], unless otherwise provided herein.
production of cut lengths. Accordingly, appropriate processing
and quality-control procedures are required by the purchaser to
9. Keywords
obtain optimum utilization of the material. Cut lengths are line
inspected visually and mechanically during production. Sheets 9.1 chromium coated; coated steel sheet; tin mill products
ANNEXES
(Mandatory Information)
A1. METHOD FOR DETERMINATION OF METALLIC-CHROMIUM COATING WEIGHT (MASS) ON
CHROMIUM-PLATED TIN-FREE STEEL
A1.1 Scope A1.3.4 Chromium, Standard Solution (1 mL = 0.02 mg
Cr)—Dissolve 0.2828 g of dry, primary standard grade potas-
A1.1.1 This method is applicable to the determination of
sium dichromate (K Cr O ) in distilled water and dilute to 500
2 2
2 2 7
from 1 to 15 mg Cr/ft [10.8 to 161 mg Cr/m ] of surface in
mL in a volumetric flask. This solution contains 0.2 mg Cr/mL.
chromium-plated tinfree steel (TFS).
Pipet a 100-mL aliquot of this stock solution to a 1-L
volumetric flask and dilute to volume with distilled water. This
A1.2 Principle
dilute standard contains 0.02 mg Cr/mL.
A1.2.1 The oxide layer is removed chemically with a hot
A1.3.5 Diphenylcarbazide Solution (0.24 %)—Dissolve
sodium hydroxide (NaOH) solution. The metallic chromium is
0.25 g of diphenylcarbazide in 95 mL of acetone. Add 5 mL of
then electrostripped at a current of from 10 to 20 mA with 1 N
glacial acetic acid, mix well, and store in a refrigerator until
NaOH solution as the electrolyte. The stripping solution after
used.
acidification is then analyzed for chromium by oxidation with
ammonium persulfate (NH ) S O ) followed by photometric
A1.3.6 Oxide Stripping Solution (Hot (90°C) 10 N NaOH
4 2 2 8
determination with diphenylcarbazide.
Solution)—Dissolve 200 g of NaOH pellets in 400 mL of water
and dilute to 500 mL. Prepare as needed.
A1.3 Reagents
A1.3.7 Silver Nitrate Solution (2 %)—Dissolve 2 g of silver
A1.3.1 Purity of Reagents—Reagent grade chemicals shall
nitrate (AgNO ) in 100 mL of water. Keep protected from light.
be used in all tests. Unless otherwise indicated, it is intended
A1.3.8 Sodium Hydroxide (Electrolyte) Solution (1 N)—
that all reagents shall conform to the specifications of the
Dissolve 40 g of NaOH pellets in 1000 mL of distilled water.
Committee on Analytical Reagents of the American Chemical
Society, where such specifications are available. Other grades A1.3.9 Sulfuric-Phosphoric Acid Mixture—Cautiously
...
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