Copper Alloy CC493K-GM (Permanent-mould (chill) cast)
Finish state
EN CC493K
Choose for medium/large series of small bushings and worm-gear blanks needing finer grain and better surface than sand casting.
Values for the GM condition
Other CC493K tempers and conditions
CC493K is listed in 4 conditions; see the grade overview at CC493K.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Sand cast | Choose for one-off or large complex housings, pump bodies and big bearing shells where section size is variable. | 135 | 260 | 18 | 65 HB | 11.5 % IACS |
GMThis page Permanent-mould (chill) cast | Choose for medium/large series of small bushings and worm-gear blanks needing finer grain and better surface than sand casting. | 145 | 280 | 15 | 70 HB | 12 % IACS |
Centrifugally cast | Choose for large-diameter bushings, sleeves and worm wheel rims where a dense, porosity-free wall is required. | 150 | 300 | 15 | 75 HB | 12 % IACS |
GCDefault Continuously cast bar / tube | The standard stocked form — continuous-cast solid bar, hollow bar and tube for machined bushings and thrust washers. | 155 | 300 | 16 | 75 HB | 12 % IACS |
What is CC493K-GM?
CC493K-GM is CC493K supplied in the GM condition — choose for medium/large series of small bushings and worm-gear blanks needing finer grain and better surface than sand casting. CC493K-GM has a yield strength of 145 MPa (21 ksi) and a tensile strength of 280 MPa (40.6 ksi) — weaker than 72% of copper alloy grades. Elongation at break is 15% and the elastic modulus is 97 GPa (14.1 Msi). CC493K-GM has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 855°C (1,571 °F). GC is the default condition FabDigit quotes; GM is available on request or by drawing note.
Advantages
- Easy to machine — 85/100, better than 93% of copper alloy grades
Limitations
- Difficult to weld — 15/100, worse than 94% of copper alloy grades
- Limited formability — 8/100, worse than 94% of copper alloy grades
- Hard to polish — 60/100, worse than 92% of copper alloy grades
- Low stiffness — 97 GPa (14.1 Msi), worse than 88% of copper alloy grades
CC493K-GM properties
Typical room-temperature values for CC493K-GM; 20 are specific to this condition. Other listed values are CC493K reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
CC493K-GM has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 855°C (1,571 °F).
Mechanical14
CC493K-GM has a yield strength of 145 MPa (21 ksi) and a tensile strength of 280 MPa (40.6 ksi) — weaker than 72% of copper alloy grades. Elongation at break is 15% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
CC493K-GM is rated for continuous service to 200°C (392 °F). It conducts heat at 57 W/m·K (32.9 BTU/hr·ft·°F), worse than 64% of copper alloy grades. Thermal expansion is 18.4 µm/m·K (10.2 µin/in·°F).
Electrical3
CC493K-GM conducts electricity at 12 % IACS, worse than 62% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of CC493K-GM takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 75%.
Manufacturability8
CC493K-GM's machinability is excellent (85/100, better than 93% of copper alloy grades); weldability poor (15/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CC493K-GM
Is CC493K easy to machine?
Very free-cutting: use sharp positive-rake carbide or HSS, high speed, light feed and generous coolant; lead gives short chips and excellent bore finish — avoid smearing the lead phase with dull tools.
Can CC493K be welded?
Essentially unweldable by fusion due to 6–8 % Pb (hot cracking, lead fume); repair by brazing, soft soldering or mechanical means and use local extraction.
Can CC493K be formed, bent or molded?
Cast-only alloy — excellent sand, chill, centrifugal and continuous castability with wide freezing range; feed heavy sections well to avoid interdendritic shrinkage, no cold forming.
What surface finishes work on CC493K?
Machined running surfaces are normally left bare and oil-grooved; can be tin- or nickel-plated, chemically patinated or lightly polished, but lead inclusions limit mirror finish.
CC493K 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 | 6 – 8 | 7 |
| Pbfree lead phase gives emergency lubrication | 6 – 8 | 7 |
| Zn | 2 – 5 | 4 |
| Niincl. Co | ≤ 2 | 0.5 |
| Fe | ≤ 0.3 | 0.1 |
| Sb | ≤ 0.3 | 0.1 |
| P | ≤ 0.1 | 0.03 |
| S | ≤ 0.1 | 0.03 |
| Al | ≤ 0.01 | 0.01 |
| Si | ≤ 0.01 | 0.01 |
| Mn | ≤ 0.2 | 0.05 |
| Cu | ≥ 78 (balance) | — |
CC493K-GM — frequently asked
What is CC493K-GM used for?
CC493K-GM is typically used for plain bearings, bushings, thrust washers, machine tool slides and general bearing castings. In short: SAE 660 equivalent bronze; free-cutting bearing casting; self-lubricating lead phase.
What is the yield strength of CC493K-GM?
CC493K-GM has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 280 MPa (40.6 ksi) — weaker than 72% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is CC493K-GM easy to machine?
Yes — machinability is rated excellent (85/100, better than 93% of copper alloy grades). Very free-cutting: use sharp positive-rake carbide or HSS, high speed, light feed and generous coolant; lead gives short chips and excellent bore finish — avoid smearing the lead phase with dull tools.
Can CC493K-GM be welded?
Not readily — weldability is rated poor (15/100). Essentially unweldable by fusion due to 6–8 % Pb (hot cracking, lead fume); repair by brazing, soft soldering or mechanical means and use local extraction.
What surface finishes work on CC493K-GM?
Machined running surfaces are normally left bare and oil-grooved; can be tin- or nickel-plated, chemically patinated or lightly polished, but lead inclusions limit mirror finish.
Can CC493K-GM be formed, bent or molded?
Cast-only alloy — excellent sand, chill, centrifugal and continuous castability with wide freezing range; feed heavy sections well to avoid interdendritic shrinkage, no cold forming.
What is the maximum service temperature of CC493K-GM?
CC493K-GM 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 CC493K-GC and CC493K-GS?
GC is the default condition — the standard stocked form — continuous-cast solid bar, hollow bar and tube for machined bushings and thrust washers. GS: choose for one-off or large complex housings, pump bodies and big bearing shells where section size is variable. Yield strength is 155 MPa in GC versus 135 MPa in GS.
Sources
- EN 1982 — Copper and copper alloys: ingots and castings (CuSn7Zn4Pb7-C, CC493K) — CEN (2017)
- C93200 High-Leaded Tin Bronze alloy datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASTM B505/B505M — Continuous Cast Copper Alloy Castings — ASTM (2018)
- GB/T 1176 ZCuSn — SAC (2013)
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.