Copper Alloy C52100 · heat-treated state
Copper Alloy C52100-O61
Properties of the O61 condition, compared with the other C52100 tempers.
Choose for deep drawing, severe forming or before a subsequent hardening cold-work step.
What is C52100-O61?
C52100-O61 is C52100 heat treated to O61 — choose for deep drawing, severe forming or before a subsequent hardening cold-work step. C52100-O61 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 61% of copper alloy grades. Elongation at break is 65% and the elastic modulus is 110 GPa (16 Msi). C52100-O61 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 854°C (1,569 °F). H04 is the default condition FabDigit quotes; O61 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 65%, better than 100% of copper alloy grades
- Forms and bends easily — 92/100, better than 89% of copper alloy grades
Limitations
- High embodied carbon — 4.6 kg CO₂/kg, worse than 82% of copper alloy grades
C52100-O61 properties
Typical room-temperature values for C52100-O61 — 12 properties are specific to this condition; the rest are grade-level values shared by every C52100 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C52100-O61 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 854°C (1,569 °F).
Mechanical12
C52100-O61 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 61% of copper alloy grades. Elongation at break is 65% and the elastic modulus is 110 GPa (16 Msi).
Thermal5
C52100-O61 is rated for continuous service to 250°C (482 °F). It conducts heat at 62 W/m·K (35.8 BTU/hr·ft·°F), worse than 58% of copper alloy grades. Thermal expansion is 18.4 µm/m·K (10.2 µin/in·°F).
Electrical3
C52100-O61 conducts electricity at 13.5 % IACS, worse than 57% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C52100-O61 takes about 72 MJ of energy and emits 4.6 kg of CO₂ — more than 86% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C52100-O61's machinability is poor (30/100, worse than 66% of copper alloy grades); weldability fair (40/100); formability excellent (92/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C52100 tempers and conditions
C52100 is also supplied in 10 other conditions. The full side-by-side table is on the C52100 overview.
- H04DefaultDefault stock temper: high strength with enough ductility for gentle forming — bushings, washers, contact strip.585 MPa yield · 170 HB
- H10Maximum strength strip for flat springs and diaphragms formed only in the bend-favourable direction.745 MPa yield · 96 HRB
- H08Classic phosphor-bronze spring strip/wire temper; low-temperature stress relief (150–200 °C) raises the elastic limit further.690 MPa yield · 93 HRB
- H06Use where higher elastic limit is needed but full spring temper would crack on forming.640 MPa yield · 91 HRB
- H02Balanced strength/formability temper for contacts and washers with 90° bends.450 MPa yield · 78 HRB
- H01Light temper when moderate bending is still required after stamping.350 MPa yield · 65 HRB
- M20As-hot-rolled mill temper of CuSn8 phosphor bronze: strength close to the annealed condition with coarse worked structure, used as stock for subsequent cold rolling or drawing.180 MPa yield · 70 HB
- O61Choose for deep drawing, severe forming or before a subsequent hardening cold-work step.170 MPa yield · 80 HB
- O60Fully soft-annealed CuSn8 (O60): lowest strength and maximum ductility for deep drawing, severe forming and coining of phosphor bronze strip, rod and wire.150 MPa yield · 60 HB
Working with C52100-O61
Is C52100 easy to machine?
Gummy and abrasive on tooling — machinability ≈20% of free-cutting brass; use sharp positive-rake carbide, high speed, light feed and generous coolant, or specify leaded C54400 if turning volume is high.
Can C52100 be welded?
Solders and brazes excellently; GTAW/GMAW possible with CuSn filler but hot-short and porosity prone — avoid oxyacetylene welding; resistance welding is fair.
Can C52100 be formed, bent or molded?
Outstanding cold formability in O61/H01; hard and spring tempers must be bent with generous radii and preferably transverse to rolling direction; stress relieve 175–200 °C /1 h after forming springs.
What surface finishes work on C52100?
Takes bright polish, tin/silver/nickel plating and chemical patination well; no anodizing — apply clear lacquer or tarnish inhibitor for decorative use.
C52100 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 |
|---|---|---|
| Sn | 7 – 9 | 8 |
| Pdeoxidizer, raises strength/wear resistance | 0.03 – 0.35 | 0.2 |
| Pb | ≤ 0.05 | — |
| Fe | ≤ 0.1 | — |
| Zn | ≤ 0.2 | — |
| CuCu + named elements ≥ 99.5% | balance | — |
C52100-O61 — frequently asked
What is C52100-O61 used for?
C52100-O61 is typically used for springs, bearings & bushings and diaphragms. In short: high-strength phosphor bronze.
What is the yield strength of C52100-O61?
C52100-O61 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 61% of copper alloy grades. Strength varies by condition: see the 11 listed tempers.
Is C52100-O61 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 66% of copper alloy grades). Gummy and abrasive on tooling — machinability ≈20% of free-cutting brass; use sharp positive-rake carbide, high speed, light feed and generous coolant, or specify leaded C54400 if turning volume is high.
Can C52100-O61 be welded?
With care — weldability is rated fair (40/100). Solders and brazes excellently; GTAW/GMAW possible with CuSn filler but hot-short and porosity prone — avoid oxyacetylene welding; resistance welding is fair.
What surface finishes work on C52100-O61?
Takes bright polish, tin/silver/nickel plating and chemical patination well; no anodizing — apply clear lacquer or tarnish inhibitor for decorative use.
Can C52100-O61 be formed, bent or molded?
Outstanding cold formability in O61/H01; hard and spring tempers must be bent with generous radii and preferably transverse to rolling direction; stress relieve 175–200 °C /1 h after forming springs.
What is the maximum service temperature of C52100-O61?
C52100-O61 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 C52100-H04 and C52100-O60?
H04 is the default condition — default stock temper: high strength with enough ductility for gentle forming — bushings, washers, contact strip. O60: fully soft-annealed CuSn8 (O60): lowest strength and maximum ductility for deep drawing, severe forming and coining of phosphor bronze strip, rod and wire. Yield strength is 585 MPa in H04 versus 150 MPa in O60.
Can FabDigit make parts in C52100-O61?
Yes — C52100-O61 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B103/B103M — Phosphor Bronze Plate, Sheet, Strip and Rolled Bar — ASTM International (2019)
- ASTM B159/B159M — Phosphor Bronze Wire — ASTM International (2018)
- EN 1654 / EN 1652 — CuSn8 (CW453K) strip and plate — CEN (2019)
- CDA Alloy Database — C52100 property sheet — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Copper and Copper Alloys — ASM International (1990)
- GB/T 2059 / GB/T 2049 QSn8-0.3 / — SAC (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.