Copper Alloy C1100-O (Annealed)
Temper · default condition
JIS C1100 · UNS C11000 · EN CR004A, Cu-ETP · GB T2
Pick for deep drawing, bending, gaskets, flexible busbar laminates and anywhere maximum conductivity and ductility are wanted.
Values for the O condition
Other C1100 tempers and conditions
C1100 is listed in 9 conditions; see the grade overview at C1100.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefaultThis page Annealed | Pick for deep drawing, bending, gaskets, flexible busbar laminates and anywhere maximum conductivity and ductility are wanted. | 69 | 225 | 45 | 45 HB | 101 % IACS |
As fabricated | Economical thick plate and extruded bar stock; properties near annealed, used where the part will be machined or re-formed. | 75 | 215 | 42 | 45 HB | 100 % IACS |
Light-annealed | Use when soft-temper formability is needed but with straighter, less springy strip and a slightly better surface than full O. | 110 | 240 | 40 | 57 HB | 100 % IACS |
Quarter hard | Choose for mild forming plus a stiffer part — clips, shields, moderately bent terminals. | 180 | 260 | 30 | 25 HRB | 100 % IACS |
Half hard | The workhorse strip/bar temper: enough strength for busbars, terminals and stamped contacts while still bendable to ~1t. | 240 | 295 | 14 | 40 HRB | 99 % IACS |
Three-quarter hard | Intermediate temper for flat springs and stamped parts needing more yield than 1/2H with limited forming. | 275 | 320 | 10 | 100 HB | 98 % IACS |
Hardened | Standard hard temper for rigid busbar, commutator bar, hard-drawn wire and machined parts where strength beats formability. | 305 | 345 | 6 | 52 HRB | 98 % IACS |
Extra hard | Heavily cold-worked strip/wire for springy contacts and high-tension conductors; forming is essentially limited to gentle bends. | 340 | 380 | 4 | 115 HB | 97 % IACS |
Spring hard | Maximum cold-worked strength for flat springs, shield fingers and fine hard wire; not formable beyond shallow bends. | 370 | 405 | 3 | 124 HB | 97 % IACS |
What is C1100-O?
C1100-O is C1100 in the O temper — pick for deep drawing, bending, gaskets, flexible busbar laminates and anywhere maximum conductivity and ductility are wanted. C1100-O has a yield strength of 69 MPa (10 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 96% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 117 GPa (17 Msi). C1100-O 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).
Advantages
- Forms and bends easily — 98/100, better than 99% of copper alloy grades
- Conducts heat well — 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades
- High electrical conductivity — 101 % IACS, better than 98% of copper alloy grades
- Ductile — tolerates forming and impact — 45%, better than 91% of copper alloy grades
Limitations
- Difficult to machine — 18/100, worse than 100% of copper alloy grades
- Low strength — 69 MPa (10 ksi), worse than 96% of copper alloy grades
C1100-O properties
Typical room-temperature values for C1100-O; 12 are specific to this condition. Other listed values are C1100 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C1100-O 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).
Mechanical13
C1100-O has a yield strength of 69 MPa (10 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 96% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C1100-O is rated for continuous service to 200°C (392 °F). It conducts heat at 391 W/m·K (225.9 BTU/hr·ft·°F), better than 98% of copper alloy grades. Thermal expansion is 17.7 µm/m·K (9.83 µin/in·°F).
Electrical3
C1100-O conducts electricity at 101 % IACS, better than 98% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C1100-O takes about 55 MJ of energy and emits 3.8 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 35%.
Manufacturability7
C1100-O's machinability is poor (18/100, worse than 100% of copper alloy grades); weldability fair (45/100); formability excellent (98/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C1100-O
Is C1100 easy to machine?
Gummy and prone to built-up edge — use sharp positive-rake tools, high speed, low feed, generous soluble-oil coolant; harder tempers cut and chip-break much better than annealed.
Can C1100 be welded?
GTAW/GMAW with high preheat and pure-argon or Ar-He shielding works, but the 0.02–0.05 % oxygen makes C1100 vulnerable to hydrogen embrittlement — avoid reducing flames/atmospheres and prefer OF copper (C1020) for critical welds; brazing and soldering are excellent.
Can C1100 be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, bend 0t, coin, spin); work-hardens fast so interstage anneals at 400–600 °C are usual, and hot working is done at 750–950 °C.
What surface finishes work on C1100?
Not anodisable; tin, nickel, silver or gold plating for contacts, chemical bright dip plus lacquer or benzotriazole for decorative/tarnish protection, and easy mirror polishing.
C1100 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 |
|---|---|---|
| Oresidual oxygen as Cu2O; typical tough-pitch range, not specified in JIS | 0.02 – 0.05 | 0.03 |
| Agcounted with Cu | ≈ 0 | 0 |
| Pbtypical cathode impurity level | ≤ 0.01 | 0 |
| Bi | ≤ 0 | 5×10⁻⁴ |
| S | ≤ 0 | 0 |
| CuCu + Ag ≥ 99.90 % per JIS H3100 (oxygen not counted) | ≥ 99.9 (balance) | — |
C1100-O — frequently asked
What is C1100-O used for?
C1100-O is typically used for electrical bus and terminals, wire and cable and general electrical fabrication. In short: asian-stock ETP equivalent; 101 % IACS conductivity; formability score 98.
What is the yield strength of C1100-O?
C1100-O has a typical yield strength of 69 MPa (10 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 96% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C1100-O easy to machine?
Not especially — machinability is rated poor (18/100, worse than 100% of copper alloy grades). Gummy and prone to built-up edge — use sharp positive-rake tools, high speed, low feed, generous soluble-oil coolant; harder tempers cut and chip-break much better than annealed.
Can C1100-O be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW with high preheat and pure-argon or Ar-He shielding works, but the 0.02–0.05 % oxygen makes C1100 vulnerable to hydrogen embrittlement — avoid reducing flames/atmospheres and prefer OF copper (C1020) for critical welds; brazing and soldering are excellent.
What surface finishes work on C1100-O?
Not anodisable; tin, nickel, silver or gold plating for contacts, chemical bright dip plus lacquer or benzotriazole for decorative/tarnish protection, and easy mirror polishing.
Can C1100-O be formed, bent or molded?
Outstanding cold formability in O temper (deep draw, bend 0t, coin, spin); work-hardens fast so interstage anneals at 400–600 °C are usual, and hot working is done at 750–950 °C.
What is the maximum service temperature of C1100-O?
C1100-O 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 C1100-O and C1100-SH?
O is the default condition — pick for deep drawing, bending, gaskets, flexible busbar laminates and anywhere maximum conductivity and ductility are wanted. SH: maximum cold-worked strength for flat springs, shield fingers and fine hard wire; not formable beyond shallow bends. Yield strength is 69 MPa in O versus 370 MPa in SH.
Sources
- JIS H3100 — Copper and copper alloy sheets, plates and strips — JSA (2018)
- JIS H3250 — Copper and copper alloy rods and bars — JSA (2021)
- ASTM B152/B152M — Copper Sheet, Strip, Plate and Rolled Bar — ASTM (2019)
- CDA Alloy C11000 (ETP) property datasheet — 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.