Copper Alloy C90800-TQ50
Supply condition
UNS C90800 · ASTM B427 C90800
TQ50 = quench hardened and tempered
Choose when maximum hardness and wear/compressive capacity are needed for heavily loaded cut gears; ductility drops to ~2%.
Values for the TQ50 condition
Other C90800 tempers and conditions
C90800 is listed in 4 conditions; see the grade overview at C90800.
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 |
TQ50This page 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-TQ50?
C90800-TQ50 is C90800 supplied in the TQ50 condition — choose when maximum hardness and wear/compressive capacity are needed for heavily loaded cut gears; ductility drops to ~2%. C90800-TQ50 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 51% of copper alloy grades. Elongation at break is 2% and the elastic modulus is 105 GPa (15.2 Msi). C90800-TQ50 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). M01 is the default condition FabDigit quotes; TQ50 is available on request or by drawing note.
Limitations
- Limited formability — 3/100, worse than 100% of copper alloy grades
- Limited ductility — 2%, worse than 98% of copper alloy grades
- Difficult to weld — 12/100, worse than 96% of copper alloy grades
- Difficult to machine — 24/100, worse than 91% of copper alloy grades
- High embodied carbon — 4.6 kg CO₂/kg, worse than 82% of copper alloy grades
C90800-TQ50 properties
Typical room-temperature values for C90800-TQ50; 21 are specific to this condition. Other listed values are C90800 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C90800-TQ50 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-TQ50 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 51% of copper alloy grades. Elongation at break is 2% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C90800-TQ50 is rated for continuous service to 230°C (446 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), worse than 76% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C90800-TQ50 conducts electricity at 10 % IACS, worse than 74% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (66/100), better than 64% of copper alloy grades.
Sustainability4
Producing a kilogram of C90800-TQ50 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-TQ50's machinability is poor (24/100, worse than 91% of copper alloy grades); weldability not recommended (12/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C90800-TQ50
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.
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.
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) | — |
C90800-TQ50 — frequently asked
What is C90800-TQ50 used for?
C90800-TQ50 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-TQ50?
C90800-TQ50 has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 51% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is C90800-TQ50 easy to machine?
Not especially — machinability is rated poor (24/100, worse than 91% 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-TQ50 be welded?
Not readily — weldability is rated not recommended (12/100). 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-TQ50?
Takes a good mechanical polish and bronze patina; tin, nickel or chromium plating is straightforward, anodizing is not applicable.
Can C90800-TQ50 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-TQ50?
C90800-TQ50 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 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.