Copper Alloy C52400 · finish state
Copper Alloy C52400-M20
Properties of the M20 condition, compared with the other C52400 tempers.
C52400 (10% tin phosphor bronze, CuSn12-type) in the as-hot-rolled mill condition — essentially unworked, giving moderate strength with high ductility and good bearing/wear behaviour.
What is C52400-M20?
C52400-M20 is C52400 supplied in the M20 condition — c52400 (10% tin phosphor bronze, CuSn12-type) in the as-hot-rolled mill condition — essentially unworked, giving moderate strength with high ductility and good bearing/wear behaviour. C52400-M20 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 57% of copper alloy grades. Elongation at break is 55% and the elastic modulus is 110 GPa (16 Msi). C52400-M20 has a density of 8.78 g/cm³ (0.317 lb/in³), heavier than 52% of copper alloy grades. It melts at 843°C (1,549 °F). H04 is the default condition FabDigit quotes; M20 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 55%, better than 98% of copper alloy grades
- Forms and bends easily — 80/100, better than 81% of copper alloy grades
C52400-M20 properties
Typical room-temperature values for C52400-M20 — 35 properties are specific to this condition; the rest are grade-level values shared by every C52400 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C52400-M20 has a density of 8.78 g/cm³ (0.317 lb/in³), heavier than 52% of copper alloy grades. It melts at 843°C (1,549 °F).
Mechanical12
C52400-M20 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 57% of copper alloy grades. Elongation at break is 55% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C52400-M20 is rated for continuous service to 200°C (392 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), worse than 66% of copper alloy grades. Thermal expansion is 18.4 µm/m·K (10.2 µin/in·°F).
Electrical3
C52400-M20 conducts electricity at 11 % IACS, worse than 69% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C52400-M20 takes about 58 MJ of energy and emits 3.7 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C52400-M20's machinability is poor (28/100, worse than 76% of copper alloy grades); weldability fair (45/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C52400 tempers and conditions
C52400 is also supplied in 9 other conditions. The full side-by-side table is on the C52400 overview.
- H04DefaultDefault stock condition: high strength with usable ductility for bushings, wear plates, formed springs and fasteners.585 MPa yield · 180 HB
- H08Standard choice for phosphor-bronze springs, diaphragms and clips requiring high fatigue life.725 MPa yield · 96 HRB
- H02Balanced strength/formability for bushings, washers and formed contacts.450 MPa yield · 145 HB
- O60Choose for deep forming, severe bending or coining before final age/work hardening.200 MPa yield · 90 HB
- M20C52400 (10% tin phosphor bronze, CuSn12-type) in the as-hot-rolled mill condition — essentially unworked, giving moderate strength with high ductility and good bearing/wear behaviour.185 MPa yield · 90 HB
Working with C52400-M20
Is C52400 easy to machine?
Rating ~20% of free-cutting brass: gummy, stringy chips — use sharp positive-rake tools, high speed, light feeds and generous flood coolant; hard tempers machine more cleanly than annealed.
Can C52400 be welded?
Fusion welding is poor (hot cracking from high Sn); prefer resistance spot/seam welding, silver brazing or soft soldering, all of which are excellent.
Can C52400 be formed, bent or molded?
Excellent cold formability in O60/H02 but work-hardens fast — plan intermediate anneals at 480–620 °C; hot working is not recommended, and cold-worked parts should be stress-relieved ~190–230 °C to avoid ammonia SCC.
What surface finishes work on C52400?
Not anodizable; takes bright polishing, tin/nickel/silver/gold plating for contacts, or chemical patina and lacquer for decorative work.
C52400 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 |
|---|---|---|
| SnEuropean CuSn12/CW454K runs 11–13% Sn | 9 – 11 | 10 |
| Pdeoxidizer, raises strength | 0.03 – 0.35 | 0.2 |
| Pb | ≤ 0.05 | — |
| Zn | ≤ 0.2 | — |
| Fe | ≤ 0.1 | — |
| Curemainder, ~88–91% | balance | — |
C52400-M20 — frequently asked
What is C52400-M20 used for?
C52400-M20 is typically used for bearings, worm gears and bushings. In short: max-tin wear phosphor bronze.
What is the yield strength of C52400-M20?
C52400-M20 has a typical yield strength of 185 MPa (26.8 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 57% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C52400-M20 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 76% of copper alloy grades). Rating ~20% of free-cutting brass: gummy, stringy chips — use sharp positive-rake tools, high speed, light feeds and generous flood coolant; hard tempers machine more cleanly than annealed.
Can C52400-M20 be welded?
With care — weldability is rated fair (45/100). Fusion welding is poor (hot cracking from high Sn); prefer resistance spot/seam welding, silver brazing or soft soldering, all of which are excellent.
What surface finishes work on C52400-M20?
Not anodizable; takes bright polishing, tin/nickel/silver/gold plating for contacts, or chemical patina and lacquer for decorative work.
Can C52400-M20 be formed, bent or molded?
Excellent cold formability in O60/H02 but work-hardens fast — plan intermediate anneals at 480–620 °C; hot working is not recommended, and cold-worked parts should be stress-relieved ~190–230 °C to avoid ammonia SCC.
What is the maximum service temperature of C52400-M20?
C52400-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 C52400-H04 and C52400-M20?
H04 is the default condition — default stock condition: high strength with usable ductility for bushings, wear plates, formed springs and fasteners. M20: c52400 (10% tin phosphor bronze, CuSn12-type) in the as-hot-rolled mill condition — essentially unworked, giving moderate strength with high ductility and good bearing/wear behaviour. Yield strength is 585 MPa in H04 versus 185 MPa in M20.
Can FabDigit make parts in C52400-M20?
Yes — C52400-M20 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 (2019)
- ASTM B139/B139M — Phosphor Bronze Rod, Bar and Shapes — ASTM (2017)
- EN 1654 / EN 12163 — CuSn12 (CW454K) — CEN (2016)
- GB/T 2059 / GB/T 2040 — QSn10-1 — SAC (2017)
- Copper Alloy C52400 datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
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.