ASTM B768-22

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: B768 − 11 (Reapproved 2016) B768 − 22
Standard Specification for
Copper-Cobalt-Beryllium Alloy and Copper-Nickel-Beryllium
Alloy Strip and Sheet
This standard is issued under the fixed designation B768; 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 the requirements for copper-cobalt-beryllium and copper-nickel-beryllium strip and sheet of the
following alloys:
Nominal Composition, %
Copper Alloy UNS No. Beryllium Cobalt Nickel
C17410 0.3 0.5 . . .
C17450 0.3 . . . 0.8
C17460 0.3 . . . 1.2
1.2 Units—Values The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are
mathematical conversions to SI units, whichunits that are provided for information only and are not considered standard.
1.3 The following safety hazard caveat pertains only to the test methods 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:
2.2 ASTM Standards:
This specification is under the jurisdiction of 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 Oct. 1, 2016May 1, 2022. Published October 2016May 2022. Originally approved in 1987. Last previous edition approved in 20112016 as
B768–11. –11 (2016). DOI: 10.1520/B0768-11R16.10.1520/B0768-22.
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’sstandard’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
B768 − 22
B194 Specification for Copper-Beryllium Alloy Plate, Sheet, Strip, and Rolled Bar
B248 Specification for General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar
B248M Specification for General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar
(Metric)
B601 Classification for Temper Designations for Copper and Copper Alloys—Wrought and Cast
B846 Terminology for Copper and Copper Alloys
E8/E8M Test Methods for Tension Testing of Metallic Materials
E18 Test Methods for Rockwell Hardness of Metallic Materials
E255 Practice for Sampling Copper and Copper Alloys for the Determination of Chemical Composition
E527E1004 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)Test Method for Determining
Electrical Conductivity Using the Electromagnetic (Eddy Current) Method
3. Terminology
3.1 For definitions of terms related to copper and copper alloys, refer to Terminology B846.
4. General Requirements
4.1 The following sections of Specification B248 constitutesor B248M constitute a part of this specificationspecification:
4.1.1 Terminology.Terminology
4.1.2 Materials and Manufacture.Manufacture
4.1.3 Workmanship, Finish, and Appearance.Appearance
4.1.4 Sampling.Sampling
4.1.5 Number of Tests and Retests.Retests
4.1.6 Specimen Preparation.Preparation
4.1.7 Test Methods.Methods
4.1.8 Significance of Numerical Limits.Limits
4.1.9 Inspection.Inspection
4.1.10 Rejection and Rehearing.Rehearing
4.1.11 Certification.Certification
4.1.12 Test Report.Report
4.1.13 Product Identification
4.1.14 Packaging and Marking.Package Marking
4.1.15 Supplementary Requirements.Requirements
4.2 In addition, when a section with a title identical to that referenced in 5.14.1 appears in this specification, it contains additional
requirements which supplement those appearing in Specification B248 or B248M.
5. Ordering Information
5.1 Include the following information when placing orders for product under this specification, as applicable:
5.1.1 ASTM designation and year of issue,issue;
B768 − 22
5.1.2 Copper alloyAlloy UNS No. designation (designation;1.1),
5.1.3 Form of material: strip or sheet,sheet;
5.1.4 Temper (Section Temper;8),
5.1.5 Tension test, if required (Section 9),
5.1.5 Dimensions: thickness and width, and length, as applicable (Section applicable;11),
5.1.6 How furnished: rolls, stock straight lengths with or without ends, specific lengths with or without ends (Section or coils;11),
5.1.7 Type of edge, if required: slit, sheared, sawed, square corners, rounded corners, rounded edges, or full rounded edges (see
Quantity – total weight or total length, as applicable;11.6),
5.1.9 Special thickness tolerances, if required (Section 11),
5.1.10 Hardness test, if required,
5.1.11 Special marking or packaging, if required,
5.1.12 Mill test report, if required,
5.1.8 Special tests or exceptions, if any, andTension test or hardness, as applicable, in accordance with Section 10.
5.1.14 Certification, if required.
5.2 If product is purchased for agencies of the U.S. Government (see the Supplementary Requirements as defined in the current
issue of SpecificationThe following options are available and, when required, shall be specified at the time of placing B248 for
additional requirements, if specified).the order:
5.2.1 Type of edge: slit, sheared, sawed, square corners, rounded corners, rounded edges, or full rounded edges;
5.2.2 Special thickness tolerances;
5.2.3 Special width or straightness tolerances;
5.2.4 Special tests or exceptions;
5.2.5 Heat identification;
5.2.6 Test report;
5.2.7 Certification;
5.2.8 Special marking or packaging.
5.2.9 If product is purchased for agencies of the U.S. government, see the Supplementary Requirements section of Specification
B248 or B248M for additional requirements.
6. Materials and Manufacture
6.1 Materials—Materials: The material of manufacture shall be cast billets or slabs of one of the alloys cited in Section 1 of this
specification. The cast material shall be of such soundness and purity as to be suitable for processing into the products prescribed
herein.
B768 − 22
6.1.1 The material of manufacture shall be cast billets or slabs of one of the alloys cited in Section 1 of this specification. The
cast material shall be of such purity and soundness as to be suitable for processing into the products prescribed herein.
6.1.2 When specified in the contract or purchase order, the heat identification or traceability is required, the purchaser shall specify
the details required.
6.2 Manufacture:
6.2.1 The product shall be manufactured by such hot working, cold working, and annealing processes as to produce a uniform
wrought structure in the finished product.
6.2.2 The product shall be hot or cold worked to the finish size, and subsequently heat-treated when required, to meet the temper
properties specified.
6.3 Edges:
6.3.1 Slit edges shall be furnished unless otherwise specified in the contract or purchase order.
7. Chemical Composition
7.1 The material shall conform to the chemical composition requirements in Table 1 for the copper alloy UNS No. designation
specified in the ordering information.
7.1.1 Results of analysis on a check sample shall conform to the composition requirements within the permitted analytical variance
specified in Table 1.
7.2 These composition limits do not preclude the presence of other elements. By agreement between the manufacturer and
purchaser, limits may be established and analysis required for unnamed elements.
7.3 For alloys in which copper is givenlisted as remainder,“remainder,” copper is the difference between the sum of results of all
the elements analyzeddetermined and 100 %. When all the elements in Table 1 are analyzed,determined, the sum of results shall
be 99.5 % minimum.
8. Temper
8.1 The standard tempers for products described in this specification are given in Table 2.
8.1.1 Copper Alloy UNS No. C17410 Strip and Sheet is offered in the TH02 ( ⁄2 HT) and TH04 (HT) tempers.
8.1.2 Copper Alloy UNS No. C17450 Strip and Sheet is offered in TH02 ( ⁄2 HT) Temper.
TABLE 1 Chemical Requirements
Composition, %
Element Copper Alloy UNS NumberNo.
C17410 C17450 C17460
Beryllium 0.15–0.50 0.15–0.50 0.15–0.50
Cobalt 0.35–0.6 . .
Nickel . 0.50–1.0 1.0–1.4
Iron, max 0.20 0.20 0.20
Zirconium, max . 0.50 0.50
Tin, max . 0.25 0.25
Silicon, max 0.20 0.20 0.20
Aluminum, max 0.20 0.20 0.20
copper remainder remainder remainder
Copper remainder remainder remainder
Copper + sum of 99.5 % min 99.5 % min 99.5 % min
named elements
B768 − 22
TABLE 2 Mechanical Property Requirements for Strip and Sheet Precipitation Heat Treated
Copper Alloy Temper Designation Tensile Strength, Yield Strength, ksi (MPa), Elongation, 2 in. Rockwell Hardness
UNS No. ksi (MPa) 0.2
...