Copper Alloy C91000
UNS C91000
C91000 is a high-tin copper casting alloy (about 14% Sn) with a large proportion of hard delta phase, giving 135 HB with 150 MPa yield and 225 MPa tensile.
Reference datasheet — C91000 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
C91000 tempers and conditions
C91000 is supplied in 6 conditions, soft to hard. M01 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Heat treated | Optional low-temperature soak to relieve casting stresses and even out coring; slightly lowers hardness, improves dimensional stability. | 145 | 220 | 2 | 125 HB | 10 % IACS |
M01Default As sand cast | Standard foundry condition for bushings, worm gears and wear plates; most widely stocked/produced form. | 150 | 225 | 1.5 | 135 HB | 9 % IACS |
As plaster cast | Near-net-shape small intricate wear parts where machining of the hard δ-phase is to be minimised. | 150 | 225 | 1.5 | 135 HB | 9 % IACS |
As hot forged and air cooled | For repeat-production small parts needing tight dimensions and a chilled, harder wear surface. | 160 | 240 | 1.5 | 145 HB | 9 % IACS |
As centrifugally cast | Choose for dense, pore-free sleeves and rings; the finer chilled structure raises strength and hardness slightly. | 165 | 250 | 2 | 140 HB | 9 % IACS |
As investment cast | Continuous-cast bar/tube stock for machined bushings — most uniform, lowest porosity, best machined surface. | 175 | 265 | 3 | 130 HB | 9 % IACS |
What is C91000?
C91000 is a high-tin copper casting alloy (about 14% Sn) with a large proportion of hard delta phase, giving 135 HB with 150 MPa yield and 225 MPa tensile. It is used for lightly loaded, low-speed wear parts such as worm gears, wear rings and sliding components, and it holds a ground or lapped bearing surface well up to 250 °C. Elongation of only 1.5% makes it brittle and intolerant of shock, edge loading or misalignment, and it can be neither worked nor fusion welded. C90800 is the alternative where slightly more ductility is required. C91000 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 830°C (1,526 °F). C91000 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 69% of copper alloy grades. Elongation at break is 1.5% and the elastic modulus is 103 GPa (14.9 Msi).
What is C91000 used for?
- worm gears
- wear rings
- sliding parts
Limitations
- Limited ductility — 1.5%, worse than 98% of copper alloy grades
- Limited formability — 5/100, worse than 98% of copper alloy grades
- Difficult to weld — 15/100, worse than 94% of copper alloy grades
- High embodied carbon — 4.6 kg CO₂/kg, worse than 82% of copper alloy grades
- Low electrical conductivity — 9 % IACS, worse than 78% of copper alloy grades
C91000 properties
Typical room-temperature values for C91000-M01; bars are the position among copper alloy grades.
Physical3
C91000 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 830°C (1,526 °F).
Mechanical15
C91000 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 69% of copper alloy grades. Elongation at break is 1.5% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C91000 is rated for continuous service to 250°C (482 °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
C91000 conducts electricity at 9 % IACS, worse than 78% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C91000 takes about 62 MJ of energy and emits 4.6 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C91000's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability poor (15/100); formability not recommended (5/100).
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. C91000 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C91000
Is C91000 easy to machine?
Machines like a hard, brittle bronze — short chips, use sharp positive-rake carbide, moderate speed and rigid setup; the δ phase is abrasive and dulls HSS quickly.
Can C91000 be welded?
Fusion welding is not recommended (hot-short, cracks readily); repair by brazing or soft soldering, or replace the casting.
Can C91000 be formed, bent or molded?
Cast only — no hot or cold working; pour with adequate risering and chills to limit inverse segregation, gas porosity and shrinkage in the wide freezing range.
C91000 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 |
|---|---|---|
| CuCu + named elements ≥ 99.4 % | 84 – 86 | 85 |
| Snforms hard δ (Cu31Sn8) phase | 14 – 16 | 15 |
| Zn | ≤ 1.5 | |
| Pb | ≤ 0.2 | |
| Nicounted with Co in some listings | ≤ 0.8 | |
| Fe | ≤ 0.2 | |
| Sb | ≤ 0.2 | |
| P | ≤ 0.05 | |
| S | ≤ 0.05 | |
| Al | ≤ 0.01 | |
| Si | ≤ 0.01 |
What surface finishes work on C91000?
Takes a fine ground/lapped bearing surface and can be polished or chemically patinated; electroplating (Ni, Sn) is possible but rarely needed.
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).
How much does C91000 cost?
C91000 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.
C91000 — frequently asked
What is C91000 used for?
C91000 is typically used for worm gears, wear rings and sliding parts. In short: hardest common tin bronze; low-speed wear parts; brittle, shock-sensitive casting.
What is the yield strength of C91000?
C91000 has a typical yield strength of 150 MPa (21.8 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 69% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C91000 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Machines like a hard, brittle bronze — short chips, use sharp positive-rake carbide, moderate speed and rigid setup; the δ phase is abrasive and dulls HSS quickly.
Can C91000 be welded?
Not readily — weldability is rated poor (15/100). Fusion welding is not recommended (hot-short, cracks readily); repair by brazing or soft soldering, or replace the casting.
What surface finishes work on C91000?
Takes a fine ground/lapped bearing surface and can be polished or chemically patinated; electroplating (Ni, Sn) is possible but rarely needed.
Can C91000 be formed, bent or molded?
Cast only — no hot or cold working; pour with adequate risering and chills to limit inverse segregation, gas porosity and shrinkage in the wide freezing range.
What is the maximum service temperature of C91000?
C91000 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C91000-M01 and C91000-M06?
M01 is the default condition — standard foundry condition for bushings, worm gears and wear plates; most widely stocked/produced form. M06: continuous-cast bar/tube stock for machined bushings — most uniform, lowest porosity, best machined surface. Yield strength is 150 MPa in M01 versus 175 MPa in M06.
How much does C91000 cost?
C91000 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
- Copper Alloy C91000 alloy data sheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (cast tin bronzes) — ASM International (1990)
- ASTM B505/B505M — Copper Alloy Continuous Castings — ASTM International (2018)
- ASTM B22 — Bronze Castings for Bridges and Turntables — ASTM International (2017)
- ASM Handbook Vol. 13B — Corrosion of copper and copper alloys — ASM International (2005)
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.