Precious Metal B541 HT-CW
Precip hard · default condition
GB B541
HT-CW = age hardened from the cold worked condition
Highest strength, hardness and wear life — standard condition for finished contact wire, rivets, brushes and slip-ring fingers.
Values for the HT-CW condition
Other B541 tempers and conditions
B541 is listed in 5 conditions; see the grade overview at B541.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Choose for deep drawing, heading of contact rivets and any severe cold forming before final age hardening. | 200 | 430 | 30 | 120 HV | 8.5 % IACS |
Stress relieved | Use for formed springs and wipers needing dimensional stability and higher elastic limit without full age hardening. | 560 | 700 | 5 | 205 HV | 8.5 % IACS |
Age hardened from the annealed condition | Pick when parts must be formed soft, then hardened in place — good hardness with usable ductility and low distortion. | 620 | 800 | 8 | 235 HV | 9.5 % IACS |
Cold worked | Drawn or rolled to temper for spring contacts where a subsequent aging bake is not wanted. | 640 | 760 | 3 | 215 HV | 8 % IACS |
HT-CWDefaultThis page Age hardened from the cold worked condition | Highest strength, hardness and wear life — standard condition for finished contact wire, rivets, brushes and slip-ring fingers. | 850 | 1,000 | 2 | 280 HV | 10 % IACS |
What is B541 HT-CW?
B541 HT-CW is B541 in the HT-CW condition — highest strength, hardness and wear life — standard condition for finished contact wire, rivets, brushes and slip-ring fingers. B541 HT-CW has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 100% of precious metal grades. Elongation at break is 2% and the elastic modulus is 105 GPa (15.2 Msi). B541 HT-CW has a density of 16 g/cm³ (0.578 lb/in³), heavier than 84% of precious metal grades. It melts at 1,000°C (1,832 °F).
Advantages
- High strength — 850 MPa (123 ksi), better than 100% of precious metal grades
- Good corrosion resistance — 98/100, better than 90% of precious metal grades
- Polishes to a fine finish — 95/100, better than 86% of precious metal grades
Limitations
- Limited ductility — 2%, worse than 98% of precious metal grades
- Limited formability — 20/100, worse than 96% of precious metal grades
- Heavy — 16 g/cm³ (0.578 lb/in³), worse than 84% of precious metal grades
- High embodied carbon — 13,000 kg CO₂/kg, worse than 81% of precious metal grades
- Low electrical conductivity — 10 % IACS, worse than 79% of precious metal grades
B541 HT-CW properties
Typical room-temperature values for B541 HT-CW; 12 are specific to this condition. Other listed values are B541 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
B541 HT-CW has a density of 16 g/cm³ (0.578 lb/in³), heavier than 84% of precious metal grades. It melts at 1,000°C (1,832 °F).
Mechanical10
B541 HT-CW has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 100% of precious metal grades. Elongation at break is 2% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
B541 HT-CW is rated for continuous service to 250°C (482 °F). It conducts heat at 55 W/m·K (31.8 BTU/hr·ft·°F), worse than 76% of precious metal grades. Thermal expansion is 15 µm/m·K (8.33 µin/in·°F).
Electrical3
B541 HT-CW conducts electricity at 10 % IACS, worse than 79% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (98/100), better than 90% of precious metal grades.
Sustainability4
Producing a kilogram of B541 HT-CW takes about 170,000 MJ of energy and emits 13,000 kg of CO₂ — more than 74% of precious metal grades. Typical recycled content is 60%.
Manufacturability8
B541 HT-CW's machinability is fair (42/100, worse than 53% of precious metal grades); weldability very good (70/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with B541 HT-CW
Is B541 easy to machine?
Machine in the aged condition with sharp, high-rake carbide or diamond tools, light cuts and full swarf recovery — all chips and coolant are refined for precious-metal value.
Can B541 be welded?
Contacts are attached by resistance or laser welding, or by brazing to Cu/CuNi carriers; fusion welding of the alloy itself is rarely done and can dissolve the age-hardening structure.
Can B541 be formed, bent or molded?
Form, draw, head and coin in the annealed condition with interstage anneals, then age harden to final properties; aged material has very little remaining ductility.
What surface finishes work on B541?
Not anodizable; surfaces are diamond-turned, burnished or lightly polished, and can be hard-gold electroplated locally — avoid mercury, halogen and sulfur-bearing compounds.
B541 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Augold content is the specified base; verify exact limits against the current ASTM B541 table | 68 – 70 | 69 |
| Ag | 24 – 26 | 25 |
| Ptprovides age-hardening response with Au-Ag | 5 – 7 | 6 |
| Other (total impurities)Cu, Ni, Zn, Fe and other trace elements | ≤ 0.15 | — |
B541 HT-CW — frequently asked
What is B541 HT-CW used for?
B541 HT-CW is typically used for connector contacts, low-level signal switches and precision relays. In short: age-hardened gold contact; highest strength in group; very limited ductility when aged.
What is the yield strength of B541 HT-CW?
B541 HT-CW has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 100% of precious metal grades. Strength varies by condition: see the 5 listed tempers.
Is B541 HT-CW easy to machine?
Not especially — machinability is rated fair (42/100, worse than 53% of precious metal grades). Machine in the aged condition with sharp, high-rake carbide or diamond tools, light cuts and full swarf recovery — all chips and coolant are refined for precious-metal value.
Can B541 HT-CW be welded?
Yes — weldability is rated very good (70/100). Contacts are attached by resistance or laser welding, or by brazing to Cu/CuNi carriers; fusion welding of the alloy itself is rarely done and can dissolve the age-hardening structure.
What surface finishes work on B541 HT-CW?
Not anodizable; surfaces are diamond-turned, burnished or lightly polished, and can be hard-gold electroplated locally — avoid mercury, halogen and sulfur-bearing compounds.
Can B541 HT-CW be formed, bent or molded?
Form, draw, head and coin in the annealed condition with interstage anneals, then age harden to final properties; aged material has very little remaining ductility.
What is the maximum service temperature of B541 HT-CW?
B541 HT-CW is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between B541 HT-CW and B541-A?
HT-CW is the default condition — highest strength, hardness and wear life — standard condition for finished contact wire, rivets, brushes and slip-ring fingers. A: choose for deep drawing, heading of contact rivets and any severe cold forming before final age hardening. Yield strength is 850 MPa in HT-CW versus 200 MPa in A.
Sources
- ASTM B541 Standard Specification for Gold Electrical Contact Alloy — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (precious metals and electrical contact materials) — ASM International (1990)
- Precious-metal electrical contact alloy datasheets (Au-Ag-Pt age-hardenable grades) — Deringer-Ney / Materion (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.