Copper Alloy C52100-M20
Finish state
UNS C52100 · ASTM B139, B103 · EN CuSn8, CW453K · JIS C5210, C5212 · GB QSn8-0.3
M20 = as hot rolled
As-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.
Values for the M20 condition
Other C52100 tempers and conditions
C52100 is listed in 11 conditions; see the grade overview at C52100.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Fully soft-annealed CuSn8 (O60): lowest strength and maximum ductility for deep drawing, severe forming and coining of phosphor bronze strip, rod and wire. | 150 | 375 | 62 | 60 HB | 13 % IACS |
Annealed | Choose for deep drawing, severe forming or before a subsequent hardening cold-work step. | 170 | 400 | 65 | 80 HB | 13.5 % IACS |
M20This page As hot rolled | As-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 | 400 | 45 | 70 HB | 13 % IACS |
Annealed to 0.025 mm grain size | Fine-grain anneal for stamped parts needing a smooth, orange-peel-free formed surface. | 195 | 420 | 60 | 78 HB | 13.5 % IACS |
Quarter hard | Light temper when moderate bending is still required after stamping. | 350 | 470 | 40 | 122 HB | 13 % IACS |
Half hard | Balanced strength/formability temper for contacts and washers with 90° bends. | 450 | 565 | 28 | 147 HB | 13 % IACS |
H04Default Full hard | Default stock temper: high strength with enough ductility for gentle forming — bushings, washers, contact strip. | 585 | 660 | 10 | 170 HB | 13 % IACS |
Extra hard | Use where higher elastic limit is needed but full spring temper would crack on forming. | 640 | 720 | 6 | 14 HRC | 13 % IACS |
Spring hard | Classic phosphor-bronze spring strip/wire temper; low-temperature stress relief (150–200 °C) raises the elastic limit further. | 690 | 760 | 4 | 93 HRB | 13 % IACS |
Hard drawn | Cold-drawn spring wire condition for coil springs, brush wire and woven mesh (ASTM B159). | 720 | 830 | 5 | 19 HRC | 13 % IACS |
Extra spring hard | Maximum strength strip for flat springs and diaphragms formed only in the bend-favourable direction. | 745 | 815 | 3 | 20 HRC | 13 % IACS |
What is C52100-M20?
C52100-M20 is C52100 supplied in the M20 condition — as-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. C52100-M20 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 59% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 110 GPa (16 Msi). C52100-M20 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; M20 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 45%, better than 91% of copper alloy grades
- Forms and bends easily — 80/100, better than 83% of copper alloy grades
C52100-M20 properties
Typical room-temperature values for C52100-M20; 34 are specific to this condition. Other listed values are C52100 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C52100-M20 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-M20 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 59% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 110 GPa (16 Msi).
Thermal5
C52100-M20 is rated for continuous service to 200°C (392 °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-M20 conducts electricity at 13 % IACS, worse than 58% 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-M20 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C52100-M20's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability fair (40/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C52100-M20
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-M20 — frequently asked
What is C52100-M20 used for?
C52100-M20 is typically used for springs, bearings & bushings and diaphragms. In short: high-strength phosphor bronze.
What is the yield strength of C52100-M20?
C52100-M20 has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 59% of copper alloy grades. Strength varies by condition: see the 11 listed tempers.
Is C52100-M20 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% 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-M20 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-M20?
Takes bright polish, tin/silver/nickel plating and chemical patination well; no anodizing — apply clear lacquer or tarnish inhibitor for decorative use.
Can C52100-M20 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-M20?
C52100-M20 is rated for continuous use to about 200°C (392 °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-M20?
Yes — C52100-M20 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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.