Copper Alloy C90800
UNS C90800 · ASTM B427 C90800
C90800 is a high-tin copper casting alloy (about 11% Sn) supplied to ASTM B427, historically specified for cut gears and worm wheels.
Reference datasheet — C90800 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 M01 condition
C90800 tempers and conditions
C90800 is supplied in 4 conditions, soft to hard. M01 is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M01Default As sand cast | Standard as-cast sand-mould condition for gear blanks, worm wheels and bearing bushings. | 152 | 303 | 5 | 80 HB | 10.5 % IACS |
As centrifugally cast | Pick for large worm-wheel rims and bushings needing sounder, denser metal than sand casting. | 170 | 330 | 6 | 85 HB | 10.5 % IACS |
As continuous cast | Continuous-cast bar/tube stock — finest structure, most uniform properties, best for machined bushings and small gears. | 180 | 345 | 6 | 90 HB | 10.5 % IACS |
Quench hardened and tempered | Choose when maximum hardness and wear/compressive capacity are needed for heavily loaded cut gears; ductility drops to ~2%. | 220 | 380 | 2 | 115 HB | 10 % IACS |
What is C90800?
C90800 is a high-tin copper casting alloy (about 11% Sn) supplied to ASTM B427, historically specified for cut gears and worm wheels. The hard delta phase gives about 80 HB with 152 MPa yield, 303 MPa tensile and service to 260 °C, and castings hob and finish-machine to a fine tooth surface with good wear resistance. Elongation is only 5%, so there is little tolerance for shock load or misalignment, and the alloy cannot be worked or reliably fusion welded. C90500 is the usual step down when impact ductility is needed. C90800 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 854°C (1,569 °F). C90800 has a yield strength of 152 MPa (22 ksi) and a tensile strength of 303 MPa (43.9 ksi) — weaker than 67% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 103 GPa (14.9 Msi).
What is C90800 used for?
- worm gears
- gear blanks
- wear plates
Advantages
- High service temperature — 260°C (500 °F), better than 75% of copper alloy grades
Limitations
- Limited formability — 8/100, worse than 94% of copper alloy grades
- Limited ductility — 5%, worse than 93% of copper alloy grades
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- High embodied carbon — 4.6 kg CO₂/kg, worse than 82% of copper alloy grades
C90800 properties
Typical room-temperature values for C90800-M01; bars are the position among copper alloy grades.
Physical3
C90800 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 854°C (1,569 °F).
Mechanical15
C90800 has a yield strength of 152 MPa (22 ksi) and a tensile strength of 303 MPa (43.9 ksi) — weaker than 67% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C90800 is rated for continuous service to 260°C (500 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), worse than 69% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C90800 conducts electricity at 10.5 % IACS, worse than 72% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C90800 takes about 62 MJ of energy and emits 4.6 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
C90800's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability poor (20/100); formability not recommended (8/100).
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. C90800 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C90800
Is C90800 easy to machine?
Machines to a fine finish but is abrasive and chip-brittle (rating ~20% of free-cutting brass); use sharp positive-rake carbide, moderate speeds, generous coolant and rigid setups for gear hobbing.
Can C90800 be welded?
Fusion welding is not recommended (hot cracking, Sn loss); repair by low-heat braze or specialised phosphor-bronze TIG only with preheat and slow cooling.
Can C90800 be formed, bent or molded?
Casting-only alloy — long freezing range causes inverse tin segregation and microporosity, so use chills, generous risering and controlled pour temperature (~1120–1180 °C); no cold forming.
C90800 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 |
|---|---|---|
| Sn | 11 – 13 | 12 |
| Pb | ≤ 0.25 | |
| Zn | ≤ 0.25 | |
| Fe | ≤ 0.15 | |
| Niincluding Co | ≤ 0.5 | |
| Sb | ≤ 0.2 | |
| P | ≤ 0.3 | 0.05 |
| S | ≤ 0.05 | |
| Al | ≤ 0.01 | |
| Si | ≤ 0.01 | |
| CuCu + named elements ≥ 99.4%; Ni counted with Cu | ≥ 85 (balance) |
What surface finishes work on C90800?
Takes a good mechanical polish and bronze patina; tin, nickel or chromium plating is straightforward, 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 C90800 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B427 C90800
How much does C90800 cost?
C90800 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.
C90800 — frequently asked
What is C90800 used for?
C90800 is typically used for worm gears, gear blanks and wear plates. In short: high-tin gear bronze; wear resistant, low ductility; hobs to fine finish.
What is the yield strength of C90800?
C90800 has a typical yield strength of 152 MPa (22 ksi) and a tensile strength of 303 MPa (43.9 ksi) — weaker than 67% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is C90800 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Machines to a fine finish but is abrasive and chip-brittle (rating ~20% of free-cutting brass); use sharp positive-rake carbide, moderate speeds, generous coolant and rigid setups for gear hobbing.
Can C90800 be welded?
Not readily — weldability is rated poor (20/100). Fusion welding is not recommended (hot cracking, Sn loss); repair by low-heat braze or specialised phosphor-bronze TIG only with preheat and slow cooling.
What surface finishes work on C90800?
Takes a good mechanical polish and bronze patina; tin, nickel or chromium plating is straightforward, anodizing is not applicable.
Can C90800 be formed, bent or molded?
Casting-only alloy — long freezing range causes inverse tin segregation and microporosity, so use chills, generous risering and controlled pour temperature (~1120–1180 °C); no cold forming.
What is the maximum service temperature of C90800?
C90800 is rated for continuous use to about 260°C (500 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C90800-M01 and C90800-TQ50?
M01 is the default condition — standard as-cast sand-mould condition for gear blanks, worm wheels and bearing bushings. TQ50: choose when maximum hardness and wear/compressive capacity are needed for heavily loaded cut gears; ductility drops to ~2%. Yield strength is 152 MPa in M01 versus 220 MPa in TQ50.
How much does C90800 cost?
C90800 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 B427 — Standard Specification for Gear Bronze Alloy Castings — ASTM International (2020)
- ASTM B505/B505M — Copper Alloy Continuous Castings — ASTM International (2018)
- CDA Alloy Datasheet C90800 (copper.org) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 15 — Casting (copper alloy foundry practice) — ASM International (2008)
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.