Copper Alloy C94700-HT
Heat-treated state
UNS C94700
Pick after solution treatment at ~775 °C, water quench and ~315 °C precipitation ageing for heavy-duty worm gears, high-pressure bushings and valve seats; elongation falls to 8% and machining is harder.
Values for the HT condition
Other C94700 tempers and conditions
C94700 is listed in 2 conditions; see the grade overview at C94700.
- F
- HT
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
FDefault As fabricated | Choose the as-cast sand or centrifugally cast state with no heat treatment for general bushings, valve bodies and parts needing run-in toughness: 165 MPa yield with 35% elongation, moderate strength. | 165 | 330 | 35 | 85 HB | 11 % IACS |
HTThis page solution treated ~775 °C, water quenched and precipitation aged ~315 °C | Pick after solution treatment at ~775 °C, water quench and ~315 °C precipitation ageing for heavy-duty worm gears, high-pressure bushings and valve seats; elongation falls to 8% and machining is harder. | 380 | 520 | 8 | 190 HB | 10 % IACS |
What is C94700-HT?
C94700-HT is C94700 heat treated to HT — pick after solution treatment at ~775 °C, water quench and ~315 °C precipitation ageing for heavy-duty worm gears, high-pressure bushings and valve seats; elongation falls to 8% and machining is harder. C94700-HT has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 77% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 117 GPa (17 Msi). C94700-HT has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 975°C (1,787 °F). F is the default condition FabDigit quotes; HT is available on request or by drawing note.
Advantages
- High strength — 380 MPa (55.1 ksi), better than 77% of copper alloy grades
Limitations
- Difficult to machine — 25/100, worse than 86% of copper alloy grades
- Limited ductility — 8%, worse than 83% of copper alloy grades
- Poor heat conductor — 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 80% of copper alloy grades
- Limited formability — 15/100, worse than 79% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
C94700-HT properties
Typical room-temperature values for C94700-HT; 17 are specific to this condition. Other listed values are C94700 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C94700-HT has a density of 8.75 g/cm³ (0.316 lb/in³), lighter than 51% of copper alloy grades. It melts at 975°C (1,787 °F).
Mechanical13
C94700-HT has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 77% of copper alloy grades. Elongation at break is 8% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C94700-HT is rated for continuous service to 200°C (392 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 80% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C94700-HT 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 C94700-HT takes about 52 MJ of energy and emits 3.6 kg of CO₂ — less than 87% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C94700-HT's machinability is poor (25/100, worse than 86% of copper alloy grades); weldability poor (25/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C94700-HT
Is C94700 easy to machine?
The unleaded composition gives tougher, stringier chips — rated near 30% of free-cutting brass, and about 20% in the heat-treated condition. Use sharp positive-rake tools, ample coolant and moderate speed with a heavier feed to prevent chip welding and built-up edge.
Can C94700 be welded?
Arc weldability is poor, with a tendency to hot cracking and tin segregation. Prefer brazing or soldering, or make small repair welds with phosphor bronze filler at low heat input; re-age heat-treated castings after welding.
Can C94700 be formed, bent or molded?
Cast product only — sand, centrifugal and continuous casting. The wide freezing range requires good feeding and riser design; the alloy is not suitable for cold forming.
What surface finishes work on C94700?
Can be polished, nickel- or chrome-plated, or chemically passivated; it cannot be anodized. Shot blast castings to remove sand before machining datum faces.
C94700 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 | 4.5 – 6 | 5 |
| NiCo counted as Ni; age-hardening element | 4.5 – 6 | 5 |
| Zn | 1 – 2.5 | 2 |
| Pblead-free grade maximum | ≤ 0.1 | — |
| Fe | ≤ 0.25 | — |
| Sb | ≤ 0.15 | — |
| Mn | ≤ 0.2 | — |
| P | ≤ 0.05 | — |
| S | ≤ 0.05 | — |
| Si | ≤ 0.01 | — |
| Al | ≤ 0.01 | — |
| Cubalance; Ag counted as Cu | ≥ 85 (balance) | — |
C94700-HT — frequently asked
What is C94700-HT used for?
C94700-HT is typically used for valve bodies, gears, marine fittings and pump components. In short: strongest cast tin bronze here; unleaded, heat-treatable grade; best corrosion resistance in family.
What is the yield strength of C94700-HT?
C94700-HT has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 77% of copper alloy grades. Strength varies by condition: see the 2 listed tempers.
Is C94700-HT easy to machine?
Not especially — machinability is rated poor (25/100, worse than 86% of copper alloy grades). The unleaded composition gives tougher, stringier chips — rated near 30% of free-cutting brass, and about 20% in the heat-treated condition. Use sharp positive-rake tools, ample coolant and moderate speed with a heavier feed to prevent chip welding and built-up edge.
Can C94700-HT be welded?
Not readily — weldability is rated poor (25/100). Arc weldability is poor, with a tendency to hot cracking and tin segregation. Prefer brazing or soldering, or make small repair welds with phosphor bronze filler at low heat input; re-age heat-treated castings after welding.
What surface finishes work on C94700-HT?
Can be polished, nickel- or chrome-plated, or chemically passivated; it cannot be anodized. Shot blast castings to remove sand before machining datum faces.
Can C94700-HT be formed, bent or molded?
Cast product only — sand, centrifugal and continuous casting. The wide freezing range requires good feeding and riser design; the alloy is not suitable for cold forming.
What is the maximum service temperature of C94700-HT?
C94700-HT 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 C94700-F and C94700-HT?
F is the default condition — choose the as-cast sand or centrifugally cast state with no heat treatment for general bushings, valve bodies and parts needing run-in toughness: 165 MPa yield with 35% elongation, moderate strength. HT: pick after solution treatment at ~775 °C, water quench and ~315 °C precipitation ageing for heavy-duty worm gears, high-pressure bushings and valve seats; elongation falls to 8% and machining is harder. Yield strength is 165 MPa in F versus 380 MPa in HT.
Sources
- ASTM B584 — Copper Alloy Sand Castings for General Applications — ASTM International (2022)
- CDA Alloy C94700 Properties Datasheet — 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)
- Continuous/centrifugal cast nickel-tin bronze bar datasheets — Concast Metal Products / National Bronze (2023)
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.