Copper Alloy C51900 · supply condition · default condition
Copper Alloy C51900-H02
Properties of the H02 condition, compared with the other C51900 tempers.
Default stocked strip temper: balanced strength and bendability for contacts, clips and washers.
What is C51900-H02?
C51900-H02 is C51900 supplied in the H02 condition — default stocked strip temper: balanced strength and bendability for contacts, clips and washers. C51900-H02 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 86% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 115 GPa (16.7 Msi). C51900-H02 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 910°C (1,670 °F).
Advantages
- High strength — 450 MPa (65.3 ksi), better than 86% of copper alloy grades
Limitations
- Difficult to machine — 25/100, worse than 85% of copper alloy grades
C51900-H02 properties
Typical room-temperature values for C51900-H02 — 7 properties are specific to this condition; the rest are grade-level values shared by every C51900 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C51900-H02 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 910°C (1,670 °F).
Mechanical12
C51900-H02 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 86% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
C51900-H02 is rated for continuous service to 200°C (392 °F). It conducts heat at 67 W/m·K (38.7 BTU/hr·ft·°F), worse than 57% of copper alloy grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
C51900-H02 conducts electricity at 15 % IACS, worse than 54% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C51900-H02 takes about 62 MJ of energy and emits 4.2 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C51900-H02's machinability is poor (25/100, worse than 85% of copper alloy grades); weldability fair (45/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C51900 tempers and conditions
C51900 is also supplied in 9 other conditions. The full side-by-side table is on the C51900 overview.
- H02DefaultDefault stocked strip temper: balanced strength and bendability for contacts, clips and washers.450 MPa yield · 78 HRB
- H10Highest cold-rolled strength; use for flat springs bent only along the rolling direction.670 MPa yield · 97 HRB
- H08Standard temper for connector springs, diaphragms and clips loaded in bending fatigue.630 MPa yield · 95 HRB
- H04Pick for flat springs and contacts with only gentle bends, where higher elastic limit matters.530 MPa yield · 87 HRB
- O60Pick for deep drawing, severe forming or coining before final heat treatment.180 MPa yield · 95 HB
Working with C51900-H02
Is C51900 easy to machine?
Machinability only ~20 % of free-cutting brass — gummy, work-hardening chips; use sharp positive-rake tools, high speed, light feeds and flood coolant.
Can C51900 be welded?
Solder and braze excellently and resistance-weld well; oxyacetylene and TIG/MIG welding are poor because of tin oxide and hot-shortness, so avoid fusion joints in springs.
Can C51900 be formed, bent or molded?
Excellent cold formability in O60/H01; hard and spring tempers must be bent with the bend axis transverse to rolling and often need a 180–230 °C post-form stress relief to set the shape.
What surface finishes work on C51900?
Not anodizable; readily electroplated with tin, nickel, silver or gold after cyanide-free cleaning, and polishes to a bright bronze finish (bright-dip or lacquer to stop tarnish).
C51900 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 | 5 – 7 | 6 |
| Pdeoxidizer; raises strength | 0.03 – 0.35 | 0.2 |
| Zn | ≤ 0.3 | — |
| Fe | ≤ 0.1 | — |
| Pb | ≤ 0.05 | — |
| CuCu + named elements 99.5 % min | balance | — |
C51900-H02 — frequently asked
What is C51900-H02 used for?
C51900-H02 is typically used for springs & contacts, connectors and bushings. In short: spring-grade phosphor bronze.
What is the yield strength of C51900-H02?
C51900-H02 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 86% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C51900-H02 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 85% of copper alloy grades). Machinability only ~20 % of free-cutting brass — gummy, work-hardening chips; use sharp positive-rake tools, high speed, light feeds and flood coolant.
Can C51900-H02 be welded?
With care — weldability is rated fair (45/100). Solder and braze excellently and resistance-weld well; oxyacetylene and TIG/MIG welding are poor because of tin oxide and hot-shortness, so avoid fusion joints in springs.
What surface finishes work on C51900-H02?
Not anodizable; readily electroplated with tin, nickel, silver or gold after cyanide-free cleaning, and polishes to a bright bronze finish (bright-dip or lacquer to stop tarnish).
Can C51900-H02 be formed, bent or molded?
Excellent cold formability in O60/H01; hard and spring tempers must be bent with the bend axis transverse to rolling and often need a 180–230 °C post-form stress relief to set the shape.
What is the maximum service temperature of C51900-H02?
C51900-H02 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 C51900-H02 and C51900-O60?
H02 is the default condition — default stocked strip temper: balanced strength and bendability for contacts, clips and washers. O60: pick for deep drawing, severe forming or coining before final heat treatment. Yield strength is 450 MPa in H02 versus 180 MPa in O60.
Can FabDigit make parts in C51900-H02?
Yes — C51900-H02 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 B139/B139M — Phosphor Bronze Rod, Bar and Shapes — ASTM International (2017)
- EN 1654 / EN 1652 — Copper and copper alloys, strip for springs and connectors (CuSn6, CW452K) — CEN (2019)
- GB/T 2059 / GB/T 2040 — (QSn6.5-0.1) — SAC (2017)
- C51900 alloy datasheet — Copper Development Association (copper.org) (2023)
- CuSn6 Werkstoff-Datenblatt — Deutsches Kupferinstitut (2005)
- 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.