Copper Alloy C1020 1/4H
Supply condition
JIS C1020 · UNS C10200 · EN CR008A, Cu-OF · GB TU2
1/4H = quarter hard
Good compromise of formability and strength for stamped terminals and shielding parts.
Values for the 1/4H condition
Other C1020 tempers and conditions
C1020 is listed in 10 conditions; see the grade overview at C1020.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Choose for deep drawing, bending, gaskets, vacuum seals and maximum conductivity. | 69 | 221 | 45 | 40 HB | 101 % IACS |
Thermomechanically controlled processed | Thick plate, extruded bus bar and large sections supplied without final anneal or cold finish; properties near soft temper. | 70 | 210 | 40 | 45 HB | 101 % IACS |
Light anneal | Strip temper when soft-temper formability is needed but with slightly higher stiffness and better flatness/punchability. | 110 | 235 | 38 | 55 HB | 101 % IACS |
1/8 hard | Minimal cold work for improved flatness and handling stiffness with near-full formability. | 195 | 250 | 30 | 63 HB | 101 % IACS |
1/4HThis page Quarter hard | Good compromise of formability and strength for stamped terminals and shielding parts. | 205 | 262 | 25 | 70 HB | 100.5 % IACS |
Half hard | Most common strip/sheet temper for busbars, lead frames and parts needing shape stability with moderate bending. | 230 | 276 | 14 | 85 HB | 100 % IACS |
Hard drawn | Standard supply condition for OF copper rod and drawn tube: straight, dimensionally accurate, moderate strength. | 250 | 290 | 12 | 92 HB | 99.5 % IACS |
Hardened | Pick for maximum strength/wear in flat conductors, waveguide flanges and machined parts where no severe bending follows. | 275 | 310 | 6 | 95 HB | 99 % IACS |
Spring hard | Thin strip/wire for spring contacts and shielding fingers where higher elastic limit is needed (conductivity slightly reduced). | 315 | 345 | 4 | 110 HB | 98 % IACS |
Extra spring hard | Highest cold-worked strength in thin strip/wire; very limited bending, softens above ~150 °C. | 345 | 380 | 3 | 118 HB | 97 % IACS |
What is C1020 1/4H?
C1020 1/4H is C1020 supplied in the 1/4H condition — good compromise of formability and strength for stamped terminals and shielding parts. C1020 1/4H has a yield strength of 205 MPa (29.7 ksi) and a tensile strength of 262 MPa (38 ksi) — weaker than 53% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 115 GPa (16.7 Msi). C1020 1/4H has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F). O is the default condition FabDigit quotes; 1/4H is available on request or by drawing note.
Advantages
- High electrical conductivity — 100.5 % IACS, better than 97% of copper alloy grades
- Conducts heat well — 390 W/m·K (225.3 BTU/hr·ft·°F), better than 96% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Readily welded — 75/100, better than 89% of copper alloy grades
- Forms and bends easily — 80/100, better than 83% of copper alloy grades
Limitations
- Difficult to machine — 25/100, worse than 86% of copper alloy grades
C1020 1/4H properties
Typical room-temperature values for C1020 1/4H; 10 are specific to this condition. Other listed values are C1020 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C1020 1/4H has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,083°C (1,981 °F).
Mechanical12
C1020 1/4H has a yield strength of 205 MPa (29.7 ksi) and a tensile strength of 262 MPa (38 ksi) — weaker than 53% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
C1020 1/4H is rated for continuous service to 250°C (482 °F). It conducts heat at 390 W/m·K (225.3 BTU/hr·ft·°F), better than 96% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
C1020 1/4H conducts electricity at 100.5 % IACS, better than 97% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C1020 1/4H takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 25%.
Manufacturability8
C1020 1/4H's machinability is poor (25/100, worse than 86% of copper alloy grades); weldability very good (75/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C1020 1/4H
Is C1020 easy to machine?
Gummy and low-rated (~20 % of B1112): use sharp, high-rake, polished-flute tools, high speed with light feed and flood emulsion; avoid built-up edge — for volume turning switch to C14500/C36000.
Can C1020 be welded?
Excellent for GTAW/EBW/laser and brazing because there is no oxygen to cause hydrogen embrittlement; preheat 200–400 °C on thick sections due to high thermal conductivity, and use Ar/He shielding.
Can C1020 be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, spinning, severe bending); interanneal at 400–600 °C when cumulative reduction exceeds ~60 %.
What surface finishes work on C1020?
Not anodisable — commonly electroplated with Ni, Ag, Sn or Au, chemically brightened, or lacquered/ROHS-passivated to prevent tarnish; polishes to a high mirror finish.
C1020 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 |
|---|---|---|
| Ooxygen ≤10 ppm — defining limit for oxygen-free copper | ≤ 0 | 5×10⁻⁴ |
| Ptypical impurity limit, ASTM B170 | ≤ 3×10⁻⁴ | — |
| Bi | ≤ 0 | — |
| Pb | ≤ 0 | — |
| S | ≤ 0 | — |
| Se | ≤ 0 | — |
| Te | ≤ 0 | — |
| CuCu (incl. Ag) min per JIS H3100 / ASTM B170 Grade 2 (C10200) | ≥ 99.96 (balance) | — |
C1020 1/4H — frequently asked
What is C1020 1/4H used for?
C1020 1/4H is typically used for electronic connectors, high-conductivity bus bar and semiconductor lead frames. In short: oxygen-free JIS copper; best copper weldability; 101 % IACS conductivity.
What is the yield strength of C1020 1/4H?
C1020 1/4H has a typical yield strength of 205 MPa (29.7 ksi) and a tensile strength of 262 MPa (38 ksi) — weaker than 53% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C1020 1/4H easy to machine?
Not especially — machinability is rated poor (25/100, worse than 86% of copper alloy grades). Gummy and low-rated (~20 % of B1112): use sharp, high-rake, polished-flute tools, high speed with light feed and flood emulsion; avoid built-up edge — for volume turning switch to C14500/C36000.
Can C1020 1/4H be welded?
Yes — weldability is rated very good (75/100). Excellent for GTAW/EBW/laser and brazing because there is no oxygen to cause hydrogen embrittlement; preheat 200–400 °C on thick sections due to high thermal conductivity, and use Ar/He shielding.
What surface finishes work on C1020 1/4H?
Not anodisable — commonly electroplated with Ni, Ag, Sn or Au, chemically brightened, or lacquered/ROHS-passivated to prevent tarnish; polishes to a high mirror finish.
Can C1020 1/4H be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, spinning, severe bending); interanneal at 400–600 °C when cumulative reduction exceeds ~60 %.
What is the maximum service temperature of C1020 1/4H?
C1020 1/4H is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C1020-O and C1020-H10?
O is the default condition — choose for deep drawing, bending, gaskets, vacuum seals and maximum conductivity. H10: highest cold-worked strength in thin strip/wire; very limited bending, softens above ~150 °C. Yield strength is 69 MPa in O versus 345 MPa in H10.
Sources
- JIS H3100 / H3250 / H3300 — Copper and copper alloy sheets, rods and tubes — JSA (2018)
- ASTM B170 — Oxygen-Free Electrolytic Copper Refinery Shapes — ASTM (2019)
- CDA Alloy Datasheet C10200 (OF 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.