Copper Alloy C31400-H04
Supply condition
UNS C31400 · ASTM B140
H04 = full hard
Pick for maximum strength, stiffness in bending and wear resistance in threaded or spring-loaded hardware; little bend ductility left.
Values for the H04 condition
Other C31400 tempers and conditions
C31400 is listed in 5 conditions; see the grade overview at C31400.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for maximum ductility when parts are cold headed, deep drawn, bent or heavily staked after forming. | 90 | 255 | 45 | 55 HB | 43 % IACS |
Quarter hard | Intermediate temper when moderate strength must be combined with some remaining bend ductility. | 195 | 305 | 28 | 85 HB | 43 % IACS |
H02Default Half hard | The standard stock temper for automatic screw-machine rod — best balance of chip control, straightness and strength. | 240 | 345 | 20 | 100 HB | 42 % IACS |
H04This page Full hard | Pick for maximum strength, stiffness in bending and wear resistance in threaded or spring-loaded hardware; little bend ductility left. | 340 | 415 | 10 | 125 HB | 41 % IACS |
Extra hard | Heavily cold-worked strip and wire where peak hardness and spring-back are wanted and no forming follows. | 400 | 455 | 6 | 140 HB | 41 % IACS |
What is C31400-H04?
C31400-H04 is C31400 supplied in the H04 condition — pick for maximum strength, stiffness in bending and wear resistance in threaded or spring-loaded hardware; little bend ductility left. C31400-H04 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 71% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 117 GPa (17 Msi). C31400-H04 has a density of 8.83 g/cm³ (0.319 lb/in³), heavier than 65% of copper alloy grades. It melts at 1,010°C (1,850 °F). H02 is the default condition FabDigit quotes; H04 is available on request or by drawing note.
Advantages
- Easy to machine — 82/100, better than 90% of copper alloy grades
- Conducts heat well — 180 W/m·K (104 BTU/hr·ft·°F), better than 75% of copper alloy grades
- High electrical conductivity — 41 % IACS, better than 75% of copper alloy grades
Limitations
- Limited service temperature — 175°C (347 °F), worse than 92% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
- Limited ductility — 10%, worse than 76% of copper alloy grades
C31400-H04 properties
Typical room-temperature values for C31400-H04; 13 are specific to this condition. Other listed values are C31400 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C31400-H04 has a density of 8.83 g/cm³ (0.319 lb/in³), heavier than 65% of copper alloy grades. It melts at 1,010°C (1,850 °F).
Mechanical12
C31400-H04 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 71% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C31400-H04 is rated for continuous service to 175°C (347 °F). It conducts heat at 180 W/m·K (104 BTU/hr·ft·°F), better than 75% of copper alloy grades. Thermal expansion is 18.4 µm/m·K (10.2 µin/in·°F).
Electrical3
C31400-H04 conducts electricity at 41 % IACS, better than 75% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C31400-H04 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
C31400-H04's machinability is very good (82/100, better than 90% of copper alloy grades); weldability poor (25/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C31400-H04
Is C31400 easy to machine?
Excellent free-cutting behaviour (≈80% of C36000): use high positive rake carbide or HSS, 200–400 m/min, light oil or emulsion; lead gives short broken chips and long tool life.
Can C31400 be welded?
Not recommended for fusion welding (lead causes hot cracking); join by soft soldering or silver brazing, which it takes very well.
Can C31400 be formed, bent or molded?
Anneal to O60 for cold heading, drawing and severe bends; H02/H04 tempers are limited to gentle bends of 1–2 t radius.
What surface finishes work on C31400?
Takes bright polishing, nickel/chrome, tin and gold plating readily; lacquer or benzotriazole treatment prevents tarnish — no anodizing.
C31400 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 |
|---|---|---|
| CuCu + named elements ≥ 99.5% | 87.5 – 90.5 | 89 |
| Pbfree-machining additive | 1.3 – 2.5 | 1.8 |
| Fe | ≤ 0.1 | — |
| Zn | balance | — |
C31400-H04 — frequently asked
What is C31400-H04 used for?
C31400-H04 is typically used for hinges, screws, hardware fittings and builders' hardware. In short: free-cutting commercial bronze; 80 % of C36000 machinability; not fusion weldable.
What is the yield strength of C31400-H04?
C31400-H04 has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 71% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C31400-H04 easy to machine?
Yes — machinability is rated very good (82/100, better than 90% of copper alloy grades). Excellent free-cutting behaviour (≈80% of C36000): use high positive rake carbide or HSS, 200–400 m/min, light oil or emulsion; lead gives short broken chips and long tool life.
Can C31400-H04 be welded?
Not readily — weldability is rated poor (25/100). Not recommended for fusion welding (lead causes hot cracking); join by soft soldering or silver brazing, which it takes very well.
What surface finishes work on C31400-H04?
Takes bright polishing, nickel/chrome, tin and gold plating readily; lacquer or benzotriazole treatment prevents tarnish — no anodizing.
Can C31400-H04 be formed, bent or molded?
Anneal to O60 for cold heading, drawing and severe bends; H02/H04 tempers are limited to gentle bends of 1–2 t radius.
What is the maximum service temperature of C31400-H04?
C31400-H04 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C31400-H02 and C31400-H06?
H02 is the default condition — the standard stock temper for automatic screw-machine rod — best balance of chip control, straightness and strength. H06: heavily cold-worked strip and wire where peak hardness and spring-back are wanted and no forming follows. Yield strength is 240 MPa in H02 versus 400 MPa in H06.
Sources
- ASTM B140/B140M — Copper-Zinc-Lead (Leaded Red Brass or Hardware Bronze) Rod, Bar and Shapes — ASTM International (2019)
- CDA/UNS C31400 alloy datasheet (copper.org Alloy Database) — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
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.