Copper Alloy C63800
UNS C63800 · ASTM B105
C63800 is a cobalt- and silicon-bearing aluminum bronze to ASTM B105, normally supplied as strip and wire from O60 annealed through H10 spring tempers.
Reference datasheet — C63800 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 H08 condition
C63800 tempers and conditions
C63800 is supplied in 9 conditions, soft to hard. H08 is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Softest supply condition for deep drawing or severe forming before final aging/work hardening. | 260 | 550 | 40 | 83 HRB | 10 % IACS |
Annealed | Standard annealed strip or wire for forming and subsequent cold-work strengthening. | 290 | 570 | 35 | 86 HRB | 10 % IACS |
Quarter hard | Light cold work when moderate strength must be combined with continued bending/forming ability. | 550 | 655 | 15 | 92 HRB | — |
Half hard | General-purpose strength/formability compromise for stamped hardware and contacts. | 650 | 725 | 10 | 95 HRB | — |
Three-quarter hard | Intermediate step between half and full hard for parts needing higher yield with a little bend allowance. | 690 | 760 | 8 | 97 HRB | — |
Full hard | Most common structural hard temper for fasteners, washers and flat stampings with mild forming. | 740 | 795 | 6 | 22 HRC | — |
Extra hard | High-yield temper for flat springs and contacts formed only along the grain with generous bend radii. | 810 | 860 | 5 | 24 HRC | — |
H08Default Spring hard | Default stocked strip/wire temper: highest practical combination of spring properties, relaxation resistance and corrosion resistance. | 855 | 895 | 4 | 25 HRC | 10 % IACS |
Extra spring hard | Maximum-strength temper for flat springs and connector fingers loaded essentially in the rolled direction only. | 895 | 930 | 3 | 27 HRC | — |
What is C63800?
C63800 is a cobalt- and silicon-bearing aluminum bronze to ASTM B105, normally supplied as strip and wire from O60 annealed through H10 spring tempers. In the default hard condition it provides 855 MPa yield, 895 MPa tensile, 4 % elongation and 99 HRB (25 HRC) with 10 % IACS conductivity, which makes it a corrosion-resistant substitute for beryllium copper in springs and spring contacts. Elongation and formability (score 20) are low, maximum service temperature is 200 °C, and welding heat destroys the cold-worked strength. C63600 is the choice when heavy forming is required. C63800 has a density of 7.69 g/cm³ (0.278 lb/in³), lighter than 90% of copper alloy grades. It melts at 1,030°C (1,886 °F). C63800 has a yield strength of 855 MPa (124 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 98% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 124 GPa (18 Msi).
What is C63800 used for?
- springs
- fasteners
- electrical/electronic spring contacts
Advantages
- High strength — 855 MPa (124 ksi), better than 98% of copper alloy grades
- Lightweight — 7.69 g/cm³ (0.278 lb/in³), better than 90% of copper alloy grades
- Good corrosion resistance — 74/100, better than 88% of copper alloy grades
Limitations
- Limited ductility — 4%, worse than 96% of copper alloy grades
- Poor heat conductor — 44.6 W/m·K (25.8 BTU/hr·ft·°F), worse than 78% of copper alloy grades
C63800 properties
Typical room-temperature values for C63800-H08; bars are the position among copper alloy grades.
Physical3
C63800 has a density of 7.69 g/cm³ (0.278 lb/in³), lighter than 90% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical13
C63800 has a yield strength of 855 MPa (124 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 98% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 124 GPa (18 Msi).
Thermal5
C63800 is rated for continuous service to 200°C (392 °F). It conducts heat at 44.6 W/m·K (25.8 BTU/hr·ft·°F), worse than 78% of copper alloy grades. Thermal expansion is 16.9 µm/m·K (9.39 µin/in·°F).
Electrical3
C63800 conducts electricity at 10 % IACS, worse than 74% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (74/100), better than 88% of copper alloy grades.
Sustainability4
Producing a kilogram of C63800 takes about 57 MJ of energy and emits 3.6 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 30%.
Manufacturability8
C63800's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability fair (45/100); formability poor (20/100).
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. C63800 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C63800
Is C63800 easy to machine?
Rated about 30 % of free-cutting brass — gummy and abrasive; use sharp carbide, positive rake, moderate speed and generous coolant, and expect built-up edge in annealed temper.
Can C63800 be welded?
GTAW/GMAW and resistance welding are feasible with aluminum-bronze filler and oxide removal, but heat destroys the cold-worked strength, so joints are usually mechanical or soldered.
Can C63800 be formed, bent or molded?
Form in O60/O61 or ¼-hard; hard and spring tempers need bend radii of 2–5 t and preferably good-way (transverse) bends, with stress relief at ~230–290 °C after forming.
C63800 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 |
|---|---|---|
| Al | 2.5 – 3.1 | 2.8 |
| Si | 1.5 – 2.1 | 1.8 |
| Co | 0.25 – 0.55 | 0.4 |
| Sn | ≤ 0.2 | |
| Zn | ≤ 0.8 | |
| Fe | ≤ 0.2 | |
| Mn | ≤ 0.1 | |
| Pb | ≤ 0.05 | |
| Cuincluding Ag; remainder | ≥ 95 (balance) |
What surface finishes work on C63800?
Takes a bright gold-bronze polish and accepts tin, nickel or gold plating after alkaline/acid cleaning to strip the tenacious Al-Si oxide; anodizing is not applicable.
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).
Equivalent designations
Standards and trade names that resolve to Copper Alloy C63800 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B105
How much does C63800 cost?
C63800 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.
C63800 — frequently asked
What is C63800 used for?
C63800 is typically used for springs, fasteners and electrical/electronic spring contacts. In short: spring-temper aluminum bronze; beryllium-free spring alternative; low formability, high strength.
What is the yield strength of C63800?
C63800 has a typical yield strength of 855 MPa (124 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 98% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C63800 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% of copper alloy grades). Rated about 30 % of free-cutting brass — gummy and abrasive; use sharp carbide, positive rake, moderate speed and generous coolant, and expect built-up edge in annealed temper.
Can C63800 be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW and resistance welding are feasible with aluminum-bronze filler and oxide removal, but heat destroys the cold-worked strength, so joints are usually mechanical or soldered.
What surface finishes work on C63800?
Takes a bright gold-bronze polish and accepts tin, nickel or gold plating after alkaline/acid cleaning to strip the tenacious Al-Si oxide; anodizing is not applicable.
Can C63800 be formed, bent or molded?
Form in O60/O61 or ¼-hard; hard and spring tempers need bend radii of 2–5 t and preferably good-way (transverse) bends, with stress relief at ~230–290 °C after forming.
What is the maximum service temperature of C63800?
C63800 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 C63800-H08 and C63800-O60?
H08 is the default condition — default stocked strip/wire temper: highest practical combination of spring properties, relaxation resistance and corrosion resistance. O60: softest supply condition for deep drawing or severe forming before final aging/work hardening. Yield strength is 855 MPa in H08 versus 260 MPa in O60.
How much does C63800 cost?
C63800 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 B105 — Hard-Drawn Copper Alloy Wires for Electric Conductors — ASTM International (2018)
- CDA Alloy Datasheet C63800 (UNS C63800) — 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)
- Spring-metal strip alloy data (aluminum-silicon bronze 638) — Specialty copper strip producers (2022)
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.