Copper Alloy C12500
UNS C12500
C12500 is a fire-refined tough pitch (FRTP) copper from the wrought C10000–C19999 family, refined commercially rather than electrolytically, so impurity control is looser than in C11000 ETP.
Reference datasheet — C12500 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the H04 condition
C12500 tempers and conditions
C12500 is supplied in 12 conditions, soft to hard. H04 is the default FabDigit quotes; the values on this page are for it.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.050 mm grain size | Soft, coarse-grain anneal for deep drawing and severe forming. | 69 | 220 | 45 | 42 HB | 100 % IACS |
As hot extruded | Standard as-extruded condition for bus bar, forging stock and machined fittings. | 70 | 215 | 50 | 42 HB | 99 % IACS |
Annealed to 0.025 mm grain size | Fine-grain soft temper — better surface finish after forming than OS050. | 76 | 235 | 45 | 45 HB | 100 % IACS |
As hot rolled | Cheapest mill condition for heavy plate and roofing sheet where temper control is not critical. | 85 | 235 | 45 | 48 HB | 99 % IACS |
1/8 hard | Slight stiffening while keeping near-soft formability; good for roll-formed profiles. | 170 | 250 | 30 | 62 HB | 98 % IACS |
Quarter hard | Balanced temper for bent brackets, gutters and moderately formed parts. | 205 | 265 | 25 | 70 HB | 98 % IACS |
Half hard | Most common cold-worked sheet/strip temper — usable strength with some bendability. | 250 | 290 | 14 | 82 HB | 97 % IACS |
Three-quarter hard | Stiffer flat product for gaskets, washers and lightly formed hardware. | 275 | 315 | 10 | 89 HB | 97 % IACS |
H04Default Full hard | Default stocked temper for bar, bus bar and hard sheet where strength and straightness matter. | 310 | 345 | 6 | 95 HB | 97 % IACS |
Extra hard | Higher cold reduction for flat springs, contacts and stiff strip; very limited bending. | 340 | 365 | 4 | 100 HB | 97 % IACS |
Spring hard | Spring-rolled strip for gaskets, shim and low-stress spring contacts. | 350 | 380 | 4 | 105 HB | 96 % IACS |
Extra spring hard | Maximum cold-worked strength available in thin strip/wire; essentially no formability. | 365 | 395 | 3 | 110 HB | 96 % IACS |
What is C12500?
C12500 is a fire-refined tough pitch (FRTP) copper from the wrought C10000–C19999 family, refined commercially rather than electrolytically, so impurity control is looser than in C11000 ETP. Engineers choose it for general non-electrical products where 97 % IACS conductivity, 385 W/m·K thermal conductivity and easy cold working are enough; it is supplied as sheet, strip, plate, bar, tube and wire. It is oxygen-bearing, so it embrittles in reducing atmospheres above about 400 °C, service is limited to 150 °C and machinability is only 22 on the free-cutting-brass scale. Use C11000 for certified electrical work or C14700/C36000 for turned parts. C12500 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F). C12500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 6% and the elastic modulus is 117 GPa (17 Msi).
What is C12500 used for?
- builder's hardware
- general sheet and wire products
- roofing
Advantages
- Conducts heat well — 385 W/m·K (222.4 BTU/hr·ft·°F), better than 92% of copper alloy grades
- High electrical conductivity — 97 % IACS, better than 92% of copper alloy grades
- Low embodied carbon — 3.3 kg CO₂/kg, better than 90% of copper alloy grades
Limitations
- Limited service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
- Limited ductility — 6%, worse than 89% of copper alloy grades
C12500 properties
Typical room-temperature values for C12500-H04; bars are the position among copper alloy grades.
Physical3
C12500 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical12
C12500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 6% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C12500 is rated for continuous service to 150°C (302 °F). It conducts heat at 385 W/m·K (222.4 BTU/hr·ft·°F), better than 92% of copper alloy grades. Thermal expansion is 17.7 µm/m·K (9.83 µin/in·°F).
Electrical3
C12500 conducts electricity at 97 % IACS, better than 92% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C12500 takes about 53 MJ of energy and emits 3.3 kg of CO₂ — less than 85% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
C12500's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability fair (35/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C12500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C12500
Is C12500 easy to machine?
Gummy and low-rated (~20 % of free-cutting brass): use sharp positive-rake tools, high speed, generous coolant, or switch to C14500/C36000 for screw-machine work.
Can C12500 be welded?
Oxygen-bearing copper — prefer brazing/soldering or friction/resistance joining; GTAW/GMAW is possible with deoxidised filler (ERCu) but risks hydrogen embrittlement and porosity, and heating above 400 °C in reducing atmospheres must be avoided.
Can C12500 be formed, bent or molded?
Excellent cold formability in OS tempers (deep draw, spin, roll-form); interanneal at 400–600 °C when total cold reduction exceeds ~50 %.
C12500 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.
| Element | Spec limit (wt %) |
|---|---|
| Ooxygen present as Cu2O (tough pitch); typically 0.02–0.05 %, not a specified limit | ≈ 0.04 |
| Sb | ≤ 0.01 |
| As | ≤ 0.01 |
| Bi | ≤ 0 |
| Fe | ≤ 0.01 |
| Pb | ≤ 0.01 |
| Ni | ≤ 0.05 |
| Se | ≤ 0 |
| S | ≤ 0 |
| Sn | ≤ 0.05 |
| Te | ≤ 0.03 |
| Zn | ≤ 0.05 |
| CuCu + Ag, fire-refined tough pitch | ≥ 99.88 (balance) |
What surface finishes work on C12500?
Not anodisable; takes bright polishing, chemical patina/oxidation blackening, tin, nickel or silver plating, and clear lacquer to slow natural tarnish.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
How much does C12500 cost?
C12500 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C12500 — frequently asked
What is C12500 used for?
C12500 is typically used for builder's hardware, general sheet and wire products and roofing. In short: low-cost general-purpose copper; 97 % IACS without ETP purity; excellent cold formability.
What is the yield strength of C12500?
C12500 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 345 MPa (50 ksi) — stronger than 64% of copper alloy grades. Strength varies by condition: see the 12 listed tempers.
Is C12500 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Gummy and low-rated (~20 % of free-cutting brass): use sharp positive-rake tools, high speed, generous coolant, or switch to C14500/C36000 for screw-machine work.
Can C12500 be welded?
With care — weldability is rated fair (35/100). Oxygen-bearing copper — prefer brazing/soldering or friction/resistance joining; GTAW/GMAW is possible with deoxidised filler (ERCu) but risks hydrogen embrittlement and porosity, and heating above 400 °C in reducing atmospheres must be avoided.
What surface finishes work on C12500?
Not anodisable; takes bright polishing, chemical patina/oxidation blackening, tin, nickel or silver plating, and clear lacquer to slow natural tarnish.
Can C12500 be formed, bent or molded?
Excellent cold formability in OS tempers (deep draw, spin, roll-form); interanneal at 400–600 °C when total cold reduction exceeds ~50 %.
What is the maximum service temperature of C12500?
C12500 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 C12500-H04 and C12500-OS050?
H04 is the default condition — default stocked temper for bar, bus bar and hard sheet where strength and straightness matter. OS050: soft, coarse-grain anneal for deep drawing and severe forming. Yield strength is 310 MPa in H04 versus 69 MPa in OS050.
How much does C12500 cost?
C12500 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B5 — Electrolytic Tough Pitch / Fire-Refined Copper Refinery Shapes — ASTM International (2021)
- ASTM B152/B152M — Copper Sheet, Strip, Plate and Rolled Bar — ASTM International (2019)
- CDA Alloy Datasheet C12500 (Fire-Refined Tough Pitch Copper) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.