ASTM B541-95

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation: B 541 – 95
Standard Specification for
1
Gold Electrical Contact Alloy
This standard is issued under the fixed designation B 541; 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 (ε) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
TABLE 1 Chemical Requirements
1. Scope
1.1 This specification covers a gold-rich, age-hardenable
Element Composition, Weight %
alloy in rod, wire, and strip form applicable to electrical
Nominal Range
contacts.
Gold 71.5 70.5–72.5
1.2 The values stated in inch-pound units are to be regarded
Platinum 8.5 8.0–9.0
as the standard. The SI units may be approximate.
Silver 4.5 4.0–5.0
Copper 14.5 13.5–15.5
1.3 The following precautionary statement pertains to the
Zinc 1.0 0.7–1.3
test method portion only, Section 7, of this specification. This
Total base metal impurities . 0.2 max
standard does not purport to address all of the safety concerns, Total platinum group metal impurities . 0.2 max
if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety and health
practices and determine the applicability of regulatory limita-
5. Condition
tions prior to use.
5.1 This specification covers the conditions and forms listed
2. Referenced Documents in Table 2.
2.1 ASTM Standards:
B 476 Specification for General Requirements for Wrought
TABLE 2 Conditions and Forms
2
Precious Metal Electrical Contact Materials
E 8 Test Methods of Tension Testing of Metallic Mate-
Process Form
3
rials Symbol
Wire Strip Rod
3
E 384 Test Method for Microhardness of Materials
Annealed A X X X
Stress relieved S-R X X
3. Materials and Manufacture
Age hardened from solution HT-A XXX
annealed condition
3.1 Raw materials shall be of such quality and purity that
Age hardened from solution annealed HT-CW XXX
the finished product will have the properties and characteristics
and cold-worked condition
prescribed in this specification.
3.2 The material shall be finished by such operations (cold
working, annealing, turning, grinding, age hardening, etc.) as
6. Mechanical Properties
are required to produce the prescribed properties.
6.1 Mechanical properties shall conform to Table 3 and
4. Chemical Composition
Table 4 as appropriate.
4.1 Materialproducedunderthisspecificationshallmeetthe
6.2 The criteria for temper designation shall be Knoop
requirements of Table 1 for chemical composition. hardness or tensile properties (ultimate tensile strength and
elongation) or both, as specified in the contract or order.
1 6.3 Mechanical properties of flattened wire, less than 0.012
This test method is under the jurisdiction of ASTM Committee B-2 on
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee in. (0.30 mm) thick shall conform to 6.1 (Table 5).
B2.05 on Precious Metals.
Current edition approved Aug. 15, 1995. Published October 1995. Originally
7. Test Methods
published as B 541 – 70. Last previous edition B 541 – 89.
2 7.1 Test methods are in accordance with Specification
Annual Book of ASTM Standards, Vol 03.04.
3
Annual Book of ASTM Standards, Vol 03.01. B 476.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
B 541–95
A
TABLE 3 Mechanical Properties of Wire (0.004 to 0.020-in. (0.12 to 0.5-mm) diameter)
Property Condition
A S-R HT-A HT-CW
Tensile strength, ksi 85–110 130–170 130–165 150–200
Tensile strength, MPa 590–760 900–1170 900–1140 1030–1380
Elongation, % in 5 in. or 125 mm 20 min 5–15 7–14 2–10
B
Hardness, Knoop, HK 180–240 270–340 280–350 310–380
100
B
Hardness, Vickers HV 180–250 270–340 285–360 290–370
100
A
See 6.2.
B
See 7.3.
A
TABLE 4 Mechanical Properties of Wire (0.021 to 0.080-in. (0.51 to 0.200-mm) diameter)
Property Condition
A S-R HT-A HT-CW
Tensile strength, ksi 80–110 130–170 130–160 145–195
Tensile strength, MPa 550–760 900–1170 900–1100 1000–1340
Elongation, % in 2 in. or 50 mm 16 min 4–14 5–14 2–10
B
Hardness, Knoop HK 180–240 270–340 270–340 290–370
100
B
Hardness, Vickers HV 180–250 270–340 285–360 290–370
100
A
See 6.2.
B
See 7.3.
A
TABLE 5 Mechanical Properties of Strip (0.003 to 0.020-in. (0.12 to 0.5-mm) thick)
Property Condition
A S-R HT-A HT-CW
Tensile strength, ksi 85–115 125–165 125–155 140–180
Tensile strength, MPa 590–790 860–1140 860–1070 970–1240
Elongation, % in 2 in. or 50 mm 12 min 3–16 3–12 2–10
B
Hardness, Knoop, HK 200–250 270–340 270–340 290–370
100
B
Hardness, Vickers HV 180–250 270–340 275–350 285–365
100
...