Copper Alloy C50100-HR50
Supply condition
UNS C50100
HR50 = stress-relieved / thermally stabilised hard strip
Low-temperature bake after cold rolling to raise elastic limit and cut stress relaxation in contact springs.
Values for the HR50 condition
Other C50100 tempers and conditions
C50100 is listed in 9 conditions; see the grade overview at C50100.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for deep drawing, severe bending or maximum electrical conductivity before forming. | 95 | 255 | 45 | 55 HB | 52 % IACS |
Quarter hard | Light cold work when moderate strength must be combined with substantial bending ductility. | 240 | 300 | 25 | 85 HB | 51 % IACS |
Half hard | General-purpose stamping temper balancing strength and formability for terminals and clips. | 290 | 345 | 15 | 100 HB | 50 % IACS |
H04Default Full hard | Most commonly stocked strip temper for contacts, connectors and light spring parts. | 350 | 390 | 8 | 115 HB | 50 % IACS |
HR50This page Stress-relieved / thermally stabilised hard strip | Low-temperature bake after cold rolling to raise elastic limit and cut stress relaxation in contact springs. | 375 | 400 | 8 | 120 HB | 53 % IACS |
Extra hard | Higher strength for flat springs where only gentle bends (large radii) are required. | 385 | 420 | 5 | 125 HB | 49 % IACS |
Hard drawn | Cold-drawn wire condition for conductor wire, pins and coiled springs. | 410 | 450 | 5 | 135 HB | 49 % IACS |
Spring hard | Spring-temper strip for contact springs needing high elastic limit and good conductivity. | 415 | 450 | 4 | 135 HB | 49 % IACS |
Extra spring hard | Maximum cold-rolled strength for flat springs with essentially no forming after rolling. | 440 | 470 | 3 | 142 HB | 48 % IACS |
What is C50100-HR50?
C50100-HR50 is C50100 supplied in the HR50 condition — low-temperature bake after cold rolling to raise elastic limit and cut stress relaxation in contact springs. C50100-HR50 has a yield strength of 375 MPa (54.4 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 75% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 117 GPa (17 Msi). C50100-HR50 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,050°C (1,922 °F). H04 is the default condition FabDigit quotes; HR50 is available on request or by drawing note.
Advantages
- Conducts heat well — 222 W/m·K (128.3 BTU/hr·ft·°F), better than 80% of copper alloy grades
- High electrical conductivity — 53 % IACS, better than 80% of copper alloy grades
- Readily welded — 60/100, better than 76% of copper alloy grades
- High strength — 375 MPa (54.4 ksi), better than 75% of copper alloy grades
Limitations
- Limited ductility — 8%, worse than 83% of copper alloy grades
C50100-HR50 properties
Typical room-temperature values for C50100-HR50; 18 are specific to this condition. Other listed values are C50100 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C50100-HR50 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,050°C (1,922 °F).
Mechanical11
C50100-HR50 has a yield strength of 375 MPa (54.4 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 75% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C50100-HR50 is rated for continuous service to 220°C (428 °F). It conducts heat at 222 W/m·K (128.3 BTU/hr·ft·°F), better than 80% of copper alloy grades. Thermal expansion is 17.8 µm/m·K (9.89 µin/in·°F).
Electrical3
C50100-HR50 conducts electricity at 53 % IACS, better than 80% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (66/100), better than 64% of copper alloy grades.
Sustainability4
Producing a kilogram of C50100-HR50 takes about 57 MJ of energy and emits 3.6 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C50100-HR50's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability good (60/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C50100-HR50
Is C50100 easy to machine?
Gummy and low-rated (~20 % of AISI 1212): use sharp positive-rake tools, high speed, light feeds and good lubrication; not a free-machining alloy.
Can C50100 be welded?
Resistance and gas-shielded arc welding are acceptable with matched or CuSn filler; oxyfuel welding is poor — avoid overheating to prevent P loss and porosity.
Can C50100 be formed, bent or molded?
Excellent cold formability in O61/H01; work-hardens quickly, so interstage anneals near 480–650 °C are used for deep-drawn or severely bent parts.
What surface finishes work on C50100?
Solders and brazes very well; commonly tin-, nickel-, silver- or gold-plated for contacts; takes a bright mechanical polish but tarnishes without plating or lacquer.
C50100 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 |
|---|---|---|
| Snlow-tin phosphor bronze; some references quote up to ~1.25 % Sn for this family | 0.5 – 0.8 | 0.65 |
| Pdeoxidiser / solid-solution strengthener | 0.01 – 0.05 | 0.03 |
| Fe | ≤ 0.05 | — |
| Zn | ≤ 0.3 | — |
| Pb | ≤ 0.05 | — |
| Curemainder, Cu + named elements ≥ 99.5 % | balance | — |
C50100-HR50 — frequently asked
What is C50100-HR50 used for?
C50100-HR50 is typically used for electrical connectors, spring contacts and terminals. In short: highest-conductivity phosphor bronze; conductive spring contact strip; poor machinability.
What is the yield strength of C50100-HR50?
C50100-HR50 has a typical yield strength of 375 MPa (54.4 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 75% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C50100-HR50 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Gummy and low-rated (~20 % of AISI 1212): use sharp positive-rake tools, high speed, light feeds and good lubrication; not a free-machining alloy.
Can C50100-HR50 be welded?
Yes — weldability is rated good (60/100). Resistance and gas-shielded arc welding are acceptable with matched or CuSn filler; oxyfuel welding is poor — avoid overheating to prevent P loss and porosity.
What surface finishes work on C50100-HR50?
Solders and brazes very well; commonly tin-, nickel-, silver- or gold-plated for contacts; takes a bright mechanical polish but tarnishes without plating or lacquer.
Can C50100-HR50 be formed, bent or molded?
Excellent cold formability in O61/H01; work-hardens quickly, so interstage anneals near 480–650 °C are used for deep-drawn or severely bent parts.
What is the maximum service temperature of C50100-HR50?
C50100-HR50 is rated for continuous use to about 220°C (428 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C50100-H04 and C50100-O61?
H04 is the default condition — most commonly stocked strip temper for contacts, connectors and light spring parts. O61: choose for deep drawing, severe bending or maximum electrical conductivity before forming. Yield strength is 350 MPa in H04 versus 95 MPa in O61.
Sources
- CDA/UNS Alloy Data Sheet C50100 (phosphor bronze) — Copper Development Association (2023)
- ASTM B103/B103M — Phosphor Bronze Plate, Sheet, Strip and Rolled Bar — ASTM International (2019)
- ASTM B105 — Hard-Drawn Copper Alloy Wires for Electric Conductors — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- GB/T 2059 / GB/T 2040 / (2017)
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.