Copper Alloy C65100-O50
Temper
UNS C65100 · ASTM B98, B96 · EN CW115C · GB QSi3-1
O50 = light annealed
Partial/light anneal — stress relieved with slightly higher strength than full soft, still readily formable.
Values for the O50 condition
Other C65100 tempers and conditions
C65100 is listed in 9 conditions; see the grade overview at C65100.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Softest condition — pick for deep drawing, heavy upsetting, hot/cold forging stock and maximum ductility. | 105 | 275 | 55 | 60 HB | 12 % IACS |
Annealed | Standard commercial annealed rod/bar temper — general fabrication, bending and machining before forming. | 120 | 290 | 50 | 65 HB | 12 % IACS |
Annealed to 0.035 mm grain size | Grain-size-controlled anneal for strip/sheet — good drawability with a fine, orange-peel-free surface. | 130 | 305 | 48 | 70 HB | 12 % IACS |
O50This page Light annealed | Partial/light anneal — stress relieved with slightly higher strength than full soft, still readily formable. | 160 | 325 | 42 | 80 HB | 12 % IACS |
Quarter hard | Light cold work — better yield strength than annealed while still allowing moderate bending and forming. | 240 | 360 | 30 | 100 HB | 12 % IACS |
Half hard | Balanced strength/ductility temper for general machined parts, shafts and moderately formed hardware. | 310 | 400 | 20 | 125 HB | 12 % IACS |
H04Default Full hard | Most commonly stocked rod/bar condition — best strength-to-cost for bolts, nuts, marine fasteners and machined fittings. | 380 | 455 | 13 | 150 HB | 12 % IACS |
Extra hard | High-strength wire/rod for load-bearing pins, rivets and screw stock where little further forming is needed. | 450 | 525 | 7 | 175 HB | 12 % IACS |
Spring hard | Maximum cold-worked strength for springs, clips and diaphragms; very limited bend formability. | 525 | 600 | 4 | 195 HB | 12 % IACS |
What is C65100-O50?
C65100-O50 is C65100 in the O50 temper — partial/light anneal — stress relieved with slightly higher strength than full soft, still readily formable. C65100-O50 has a yield strength of 160 MPa (23.2 ksi) and a tensile strength of 325 MPa (47.1 ksi) — weaker than 65% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi). C65100-O50 has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 1,030°C (1,886 °F). H04 is the default condition FabDigit quotes; O50 is available on request or by drawing note.
Advantages
- Readily welded — 94/100, better than 100% of copper alloy grades
- Ductile — tolerates forming and impact — 42%, better than 86% of copper alloy grades
- Forms and bends easily — 82/100, better than 83% of copper alloy grades
C65100-O50 properties
Typical room-temperature values for C65100-O50; 12 are specific to this condition. Other listed values are C65100 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C65100-O50 has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical14
C65100-O50 has a yield strength of 160 MPa (23.2 ksi) and a tensile strength of 325 MPa (47.1 ksi) — weaker than 65% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C65100-O50 is rated for continuous service to 230°C (446 °F). It conducts heat at 57 W/m·K (32.9 BTU/hr·ft·°F), worse than 64% of copper alloy grades. Thermal expansion is 17.9 µm/m·K (9.94 µin/in·°F).
Electrical3
C65100-O50 conducts electricity at 12 % IACS, worse than 62% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C65100-O50 takes about 58 MJ of energy and emits 3.9 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C65100-O50's machinability is poor (27/100, worse than 81% of copper alloy grades); weldability excellent (94/100); formability very good (82/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C65100-O50
Is C65100 easy to machine?
Gummy, stringy chips — rating ≈30% of free-cutting brass; use sharp positive-rake tools, high speed, generous feed and flood coolant to avoid built-up edge.
Can C65100 be welded?
Excellent with GTAW/GMAW using ERCuSi-A filler, argon shielding, low heat input and no preheat; resistance and brazing/soldering also very good.
Can C65100 be formed, bent or molded?
Annealed tempers cold head, draw and bend readily; anneal at 480–650 °C between heavy operations and hot work at 700–875 °C.
What surface finishes work on C65100?
Takes a bright polish and chemical patina/statuary finishes; readily tin, nickel or chrome plated — anodizing does not apply.
C65100 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 |
|---|---|---|
| Siprimary solid-solution strengthener | 0.8 – 2 | 1.5 |
| Mn | ≤ 0.7 | 0.3 |
| Fe | ≤ 0.8 | — |
| Zn | ≤ 1.5 | — |
| Pb | ≤ 0.05 | — |
| CuCu + Ag, remainder | ≥ 96 (balance) | — |
C65100-O50 — frequently asked
What is C65100-O50 used for?
C65100-O50 is typically used for fasteners, marine hardware, architectural trim and electrical hardware. In short: most weldable silicon bronze; general-purpose marine bronze; good cold-heading formability.
What is the yield strength of C65100-O50?
C65100-O50 has a typical yield strength of 160 MPa (23.2 ksi) and a tensile strength of 325 MPa (47.1 ksi) — weaker than 65% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C65100-O50 easy to machine?
Not especially — machinability is rated poor (27/100, worse than 81% of copper alloy grades). Gummy, stringy chips — rating ≈30% of free-cutting brass; use sharp positive-rake tools, high speed, generous feed and flood coolant to avoid built-up edge.
Can C65100-O50 be welded?
Yes — weldability is rated excellent (94/100). Excellent with GTAW/GMAW using ERCuSi-A filler, argon shielding, low heat input and no preheat; resistance and brazing/soldering also very good.
What surface finishes work on C65100-O50?
Takes a bright polish and chemical patina/statuary finishes; readily tin, nickel or chrome plated — anodizing does not apply.
Can C65100-O50 be formed, bent or molded?
Annealed tempers cold head, draw and bend readily; anneal at 480–650 °C between heavy operations and hot work at 700–875 °C.
What is the maximum service temperature of C65100-O50?
C65100-O50 is rated for continuous use to about 230°C (446 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C65100-H04 and C65100-O60?
H04 is the default condition — most commonly stocked rod/bar condition — best strength-to-cost for bolts, nuts, marine fasteners and machined fittings. O60: softest condition — pick for deep drawing, heavy upsetting, hot/cold forging stock and maximum ductility. Yield strength is 380 MPa in H04 versus 105 MPa in O60.
Sources
- ASTM B98/B98M Copper-Silicon Alloy Rod, Bar and Shapes — ASTM International (2019)
- ASTM B96/B96M Copper-Silicon Alloy Plate, Sheet, Strip and Rolled Bar — ASTM International (2016)
- CDA Alloy Datasheet C65100 (Low Silicon Bronze B) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.