ASTM B740-21

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B740 − 09 (Reapproved 2015) B740 − 21
Standard Specification for
Copper-Nickel-Tin Spinodal Alloy Strip
This standard is issued under the fixed designation B740; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This specification establishes requirements for copper-nickel-tin alloy strip for Copper Alloy UNS Nos. C72700, C72900, and
C72650 in the following alloys:
Nominal Composition Weight %
Copper Alloy UNS No.
Copper Nickel Tin
C72700 85 9 6
C72900 77 15 8
C72650 87.5 7.5 5
1.2 Units—The values stated in inch-pound units and the values stated in SI units in Table 5 are to be regarded as standard, except
for grain size which is stated in metric units only. standard. The values given in parentheses are mathematical conversions to SI
units andthat are provided for information only and are not considered standard.
1.3 The following safety hazard caveat pertains only to the test method(s) described in this specification.
1.3.1 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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.
2. Referenced Documents
2.1 The following documents of the issue in effect on date of material purchase form a part of this specification to the extent
referenced herein:
2.1 ASTM Standards:
B248 Specification for General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar
This specification is under the ASTM Committee B05 on Copper and Copper Alloys and is the direct responsibility of Subcommittee B05.01 on Plate, Sheet, and Strip.
Current edition approved May 1, 2015Oct. 1, 2021. Published June 2015November 2021. Originally approved in 1984. Last previous edition approved in 20092015 as
B740 – 09.B740 – 09 (2015). DOI: 10.1520/B0740-09R15.10.1520/B0740-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 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 the ASTM website.
*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
B740 − 21
B248M Specification for General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar
(Metric)
B598 Practice for Determining Offset Yield Strength in Tension for Copper Alloys (Withdrawn 2019)
B601 Classification for Temper Designations for Copper and Copper Alloys—Wrought and Cast
B820 Test Method for Bend Test for Determining the Formability of Copper and Copper Alloy Strip
B846 Terminology for Copper and Copper Alloys
E3 Guide for Preparation of Metallographic Specimens
E8/E8M Test Methods for Tension Testing of Metallic Materials
E75 Test Methods for Chemical Analysis of Copper-Nickel and Copper-Nickel-Zinc Alloys (Withdrawn 2010)
E290E112 Test Methods for Bend Testing of Material for DuctilityDetermining Average Grain Size
E478 Test Methods for Chemical Analysis of Copper Alloys
3. General Requirements
3.1 The following sections of Specification B248 constitute a part of this specification:
3.1.1 Terminology,Terminology
3.1.2 Materials and Manufacture,Manufacture
3.1.3 Sampling
3.1.4 Number of Tests and Retests
3.1.5 Dimensions and Permissible Variations,Variations
3.1.6 Workmanship, Finish, and Appearance,Appearance
3.1.5 Sampling,
3.1.7 Significance of Numerical Limits,Limits
3.1.8 Inspection,Inspection
3.1.9 Rejection and Rehearing,Rehearing
3.1.10 Certification,Certification
3.1.11 Test Reports, andReports
3.1.12 Packaging and Package Marking.Marking
3.2 In addition, when a section with a title identical to that referenced in 3.1 above, above, appears in this specification, it contains
additional requirements that supplement those appearing in Specification B248.
4. Terminology
4.1 For definitions of terms related to copper and copper alloys, refer to Terminology B846.
5. Ordering Information
5.1 Include the following information specified choices when placing orders for product under this specification, as applicable:
5.1.1 ASTM designation and year of issue,
5.1.2 Quantity,
The last approved version of this historical standard is referenced on www.astm.org.
B740 − 21
5.1.2 Copper Alloy UNS No. (see No.;1.1),
5.1.3 Form of material: strip,Quantity;
5.1.4 Temper (see (8.1),);
5.1.5 Dimensions: thickness and width, and length, if applicable,applicable;
5.1.6 How furnished: rolls or coils, stock lengths with or without ends, specific lengths with or without ends,ends; and
5.1.7 Type of edge other than slit, for example, rounded corners, rounded edges, or full-rounded edges.
5.1.9 When material is purchased for agencies of the U.S. Government, this shall be specified in the contract or purchase order,
and the material shall conform to the Supplementary Requirements Section as defined in the current edition of Specification B248.
5.2 The following options are available and should and, when required, shall be specified at the time of placing of the order when
required:order.
5.2.1 Certification, if required.
5.2.2 Mill test report, if required.Test report, and
5.2.3 If product is purchased for agencies of the U.S. government, see the Supplementary Requirements Section of Specification
B248 or Specification B248M.
6. Materials and Manufacture
6.1 Materials:
6.1.1 The material of manufacture shall be strip of Copper Alloy UNS No. C72650, C72700, or C72900 of such purity and
soundness as to be suitable for the products prescribed herein.
6.2 Manufacture:
6.2.1 The product shall be manufactured by such hot working, cold working, and thermal treatment processes as to produce a
uniform wrought structure in the finished product.
6.2.2 Solution-heat-treatment or solution-heat-treated and cold-worked material is normally spinodal hardened by the purchaser
after forming or machining.
6.2.3 Mill-hardened products have been spinodal heat treated by the manufacturer. Further thermal treatment is not normally
required.
7. Chemical Composition
7.1 The material shall conform to the chemical composition requirements specified in Table 1 for the copper alloy UNS No.
TABLE 1 Chemical Requirements
Composition, %
Copper, Nickel,
A A A A A A
Copper Alloy Previous
Lead, Iron, Zinc, Manganese, Niobium, Magnesium,
incl. incl. Tin
max max max max max max
UNS No. Designation
Silver Cobalt
C72650 Cu-7.5Ni-5Sn remainder 0.01 0.10 0.10 7.0–8.0 4.5–5.5 0.10 . .
B
C72700 Cu-9Ni-6Sn remainder 0.02 0.50 0.50 8.5–9.5 5.5–6.5 0.05-0.30 0.10 0.15
B
C72900 Cu-15Ni-8Sn remainder 0.02 0.50 0.50 14.5–15.5 7.5–8.5 0.30 0.10 0.15
A
The total of the elements Pb, Fe, Zn, Mn, Nb, and Mg not to exceed 0.7 %.
B
0.005 % Pb, max for hot rolling.
B740 − 21
designation specified in the ordering information.
7.2 These composition limits do not preclude the presence of other elements. By agreement between the manufacturer or supplier
and purchaser, limits may be established and analysis required for unnamed elements.
7.3 Copper may be given as remainder and taken as For alloys in which copper is listed as “remainder,” copper is the difference
between the sum of results of all the elements analyzeddetermined and 100%.100 %. When all the elements in theTable 1 table
including copper are analyzed, their sum are determined, the sum of results shall be 99.7 % min.
7. Materials and Manufacture
7.1 Manufacture—Spinodal Heat Treatment.
7.1.1 Solution-heat-treatment or solution-heat-treated and cold-worked material is normally spinodal hardened by the purchaser
after forming or machining.
7.1.2 Mill-hardened products have been spinodal heat treated by the manufacturer. Further thermal treatment is not normally
required.
8. Temper
8.1 The standard tempers for products described in this specification are given in Tables 2-4Table 2, Table 3, and Table 4.
8.1.1 TB00 (Solution Heat Treated).
8.1.2 TD01 to TD 12 TD12 (Solution Heat Treated with varying degrees of cold working).
8.1.3 TX00 (Spinodal Hardened).
8.1.4 TS01 to TS12 (Hard and Spinodal Hardened).
8.1.5 TM00 to TS08 (mill hardened).(Mill Hardened).
8.2 Other tempers are available and shall be subject to agreement between supplier or manufacturerSpecial combinations of
properties may be obtained by special heat treatments. These requirements shall be agreed upon by the manufacturer or supplier
and purchaser.
9. Grain Size for Annealed Tempers
9.1 Grain size shall be the standard requirement for product over 0.010 in. (0.25 mm) in thickness for tempers TB00, TX00, and
TM00.
9.2 Product over 0.010 in. (0.25 mm) in thickness shall have an average grain-size not exceedingAcceptance or rejection based
upon grain size shall depend only on the average grain size of a test specimen taken from each of two sample portions, and each
specimen shall not exceed the limits prescribed in Table 5. The determinations are made on the separate samples and in a plane
perpendicular to when tested in accordance with Test Methods E112the surface.
9.3 Grain size shall be determined in a plane perpendicular to the surface.
10. Mechanical Property Requirements
10.1 Tensile Strength Requirements:
10.1.1 The solution heat-treated or solution heat-treated and cold-worked material shall conform to the tensile property
requirements specified in Table 2, when tested in accordance with Test Methods E8/E8M.
10.1.2 The spinodal heat-treated material shall conform to the tensile property requirements specified in Table 3.
B740 − 21
TABLE 2 Tensile Property Requirements
Tempers: Solution Heat-Treated
Solution Heat-Treated and Cold Worked
D
Yield
Tensile
Temper Designations
Strength
Copper Alloy Strength, Elongation
(0.05 % Offset),
A B
UNS No. A B in 2 in., %
ksi (MPa)
ksi (MPa)
C
Code Name
C
min–max
min–max
C72650 TB00 Solution HT 55–70 21—32 32
C72650 TB00 Solution HT 55–70 21–32 32
(380—480) (145–220)
(380–480) (145–220)
C72650 TD01 Solution HT and Cold Worked ⁄4 Hard 60–75 45–60 18
(415–515) (310–415)
C72650 TD02 Solution HT and Cold Worked ⁄2 Hard 75—85 55–75 5
C72650 TD02 Solution HT and Cold Worked ⁄2 Hard 75–85 55–75 5
(515—585) (380–515)
(515–585) (380–515)
C72650 TD03 Solution HT and Cold Worked ⁄4 Hard 80–90 68–82 4
(550–620) (470–565)
C72650 TD04 Solution HT and Cold Worked Hard 85–95 77–90 2
(585–655) (530–620)
C72700 TB00 Solution HT 60–80 23–33 30
(410–550) (160–230)
(415–550) (160–230)
C72700 TD01 Solution HT and Cold Worked ⁄4 Hard 72–95 48–64 12
(500–660) (330–440)
C72700 TD02 Solution HT and Cold Worked ⁄2 Hard 82–108 57–80 6
(570–740) (390–550)
C72700 TD04 Solution HT and Cold Worked Hard 97–125
...