Copper Alloy C53400-H06
Supply condition
UNS C53400 · EN CW458K
H06 = extra hard
Higher elastic limit for flat springs and clips that need only gentle forming.
Values for the H06 condition
Other C53400 tempers and conditions
C53400 is listed in 8 conditions; see the grade overview at C53400.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As hot rolled | Hot-rolled bar/plate stock for machined bushings where temper control is not required. | 140 | 310 | 45 | 65 HB | 19 % IACS |
Soft annealed | Pick for deep drawing, severe bending or heavy forming before a final temper. | 145 | 320 | 48 | 60 HB | 20 % IACS |
Quarter hard | Light cold work for moderate forming plus better stiffness than annealed. | 290 | 380 | 22 | 110 HB | 18 % IACS |
Half hard | Balanced strength and residual bend ductility for stamped contacts and washers. | 380 | 435 | 10 | 135 HB | 18 % IACS |
H04Default Full hard | The standard stock condition for screw-machine bushings, spacers and contact springs. | 450 | 490 | 6 | 150 HB | 18 % IACS |
H06This page Extra hard | Higher elastic limit for flat springs and clips that need only gentle forming. | 515 | 550 | 4 | 170 HB | 18 % IACS |
Spring hard | Spring-temper strip for contact fingers and load-bearing spring washers. | 545 | 585 | 3.5 | 180 HB | 18 % IACS |
Extra spring hard | Maximum cold-worked strength; use only for flat, near-straight spring parts. | 570 | 620 | 3 | 190 HB | 18 % IACS |
What is C53400-H06?
C53400-H06 is C53400 supplied in the H06 condition — higher elastic limit for flat springs and clips that need only gentle forming. C53400-H06 has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 110 GPa (16 Msi). C53400-H06 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 955°C (1,751 °F). H04 is the default condition FabDigit quotes; H06 is available on request or by drawing note.
Advantages
- High strength — 515 MPa (74.7 ksi), better than 91% of copper alloy grades
- Easy to machine — 76/100, better than 81% of copper alloy grades
Limitations
- Limited ductility — 4%, worse than 96% of copper alloy grades
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
C53400-H06 properties
Typical room-temperature values for C53400-H06; 13 are specific to this condition. Other listed values are C53400 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C53400-H06 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 955°C (1,751 °F).
Mechanical13
C53400-H06 has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C53400-H06 is rated for continuous service to 150°C (302 °F). It conducts heat at 84 W/m·K (48.5 BTU/hr·ft·°F), better than 51% of copper alloy grades. Thermal expansion is 17.8 µm/m·K (9.89 µin/in·°F).
Electrical3
C53400-H06 conducts electricity at 18 % IACS, better than 51% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (66/100), better than 64% of copper alloy grades.
Sustainability4
Producing a kilogram of C53400-H06 takes about 62 MJ of energy and emits 4 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C53400-H06's machinability is very good (76/100, better than 81% of copper alloy grades); weldability poor (30/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C53400-H06
Is C53400 easy to machine?
Free-cutting for a bronze (≈80 % of C36000): use sharp positive-rake carbide or HSS, high speed, light feed and oil-based coolant; lead gives short chips.
Can C53400 be welded?
Fusion welding is not recommended (lead causes hot cracking); join by soft soldering or silver brazing with low-heat input, or use mechanical fastening.
Can C53400 be formed, bent or molded?
Excellent cold formability in O60/H01; H04 and harder tempers should be limited to gentle bends (bend across the rolling direction) and stress-relieved at 190–230 °C after forming.
What surface finishes work on C53400?
Takes tin, nickel, silver and gold plating well; can be buffed to a bright bronze finish or chemically darkened — anodizing does not apply.
C53400 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 | 3.5 – 5.8 | 4.5 |
| Pbfree-machining addition | 0.8 – 1.2 | 1 |
| Pdeoxidizer / strengthener | 0.03 – 0.35 | 0.15 |
| Zn | ≤ 0.3 | — |
| Fe | ≤ 0.1 | — |
| Curemainder, Cu + named elements 99.5 % min | ≥ 92 (balance) | — |
C53400-H06 — frequently asked
What is C53400-H06 used for?
C53400-H06 is typically used for bushings, bearings and precision machined parts. In short: free-cutting phosphor bronze; spring strength with machinability; not fusion weldable.
What is the yield strength of C53400-H06?
C53400-H06 has a typical yield strength of 515 MPa (74.7 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 91% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C53400-H06 easy to machine?
Yes — machinability is rated very good (76/100, better than 81% of copper alloy grades). Free-cutting for a bronze (≈80 % of C36000): use sharp positive-rake carbide or HSS, high speed, light feed and oil-based coolant; lead gives short chips.
Can C53400-H06 be welded?
Not readily — weldability is rated poor (30/100). Fusion welding is not recommended (lead causes hot cracking); join by soft soldering or silver brazing with low-heat input, or use mechanical fastening.
What surface finishes work on C53400-H06?
Takes tin, nickel, silver and gold plating well; can be buffed to a bright bronze finish or chemically darkened — anodizing does not apply.
Can C53400-H06 be formed, bent or molded?
Excellent cold formability in O60/H01; H04 and harder tempers should be limited to gentle bends (bend across the rolling direction) and stress-relieved at 190–230 °C after forming.
What is the maximum service temperature of C53400-H06?
C53400-H06 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C53400-H04 and C53400-M20?
H04 is the default condition — the standard stock condition for screw-machine bushings, spacers and contact springs. M20: hot-rolled bar/plate stock for machined bushings where temper control is not required. Yield strength is 450 MPa in H04 versus 140 MPa in M20.
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)
- CDA Alloy Datasheet C53400 — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- EN 12163 / EN 12164 — Copper and copper alloys, rod for general and free-machining purposes (CuSn-Pb grades) — CEN (2016)
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.