C64200, C642 Silicon Aluminum Bronze (AMS 4634)
C64200 Silicon Aluminum Bronze is an engineering alloy at least as resistant to corrosion as copper itself, but much stronger. CDA 642 bronze is manufactured mostly in the form of round, hexagonal, and octagonal rods for hot forming and free machining. C642 is considered to be of the best valve stem alloys. Other applications include gears, marine hardware, nuts, pole line hardware, and valve bodies and components.
- EU Designation: CuAl7Si2, CW302G
- ASTM B150, ASTM B249, QQ-C-465, AMS 4634, SAE J461, SAE J463
Typical Uses for C64200 Silicon Aluminum Bronze:
AUTOMOTIVE: Valve Guides, Automobile Engine
ELECTRICAL: Pole Line Hardware
FASTENERS: Bolts, Nuts
INDUSTRIAL: Valve Components, Valve Bodies, Gears, Valve Stems, Cams
MARINE: Hardware
Aluminum is the main alloying metal added to copper in aluminum bronze alloys such as C64200, also known as C642. A variety of aluminum bronzes of differing compositions have found industrial use, with most ranging from 5.00% to 11.00% aluminum by weight, the remaining mass being copper. Other alloying agents such as iron, nickel, manganese, and silicon are also oftentimes added. Aluminum bronzes are most valued for their high strength and corrosion resistance.
AMS 4634-C64200
Product description: Aluminum bronze
Tempers: HR50 drawn and stress relieved
Solids: 3/16″ to 6″ O.D.
Hex: 1/2″ to 2″ O.D.
Standard lengths: 144″
Typical uses
Automotive: valve guides (automobile engine)
Electrical: pole line hardware
Fasteners: bolts, nuts
Industrial: cams, gears, valve bodies, valve components, valve stems
Marine: hardware
Similar or equivalent specification
| CDA | ASTM | SAE | AMS | Federal | Military | Other |
|---|---|---|---|---|---|---|
| C64200 | B150 B150M | J461 J463 | 4634 | QQ-C-465 |
Chemical composition
| Cu%1 | Pb% | Sn% | Zn% | Fe% | Ni%2 | Al% | Mn% | Si% | |||
|---|---|---|---|---|---|---|---|---|---|---|---|
1Cu value includes Ag. 2Ni value includes Co. Note: Cu + sum of named elements, 99.5% min. Single values represent maximums. | |||||||||||
| Rem. | 0.05 | 0.20 | 0.50 | 0.30 | 0.25 | 6.30- 7.60 | 0.10 | 1.50- 2.20 | |||
Machinability
| Copper alloy UNS No. | Machinability rating | Density (lb/in3 at 68 °F) |
|---|---|---|
| C64200 | 60 | 0.278 |
Mechanical properties
C64200
HR50 drawn and stress relieved Temper
Size range: up to 1/2″ bars and rods inclusive
| Tensile strength, min | Yield strength, at 0.5% extension under load,, min | Elongation, in 4D, min | Hardness, internal | Remarks | ||
|---|---|---|---|---|---|---|
| ksi | MPa | ksi | MPa | % | HRB | |
| 90 | 621 | 45 | 310 | 9 | >80 inclusive | |
Size range: 1/2″ to 1″ bars and rods inclusive
| Tensile strength, min | Yield strength, at 0.5% extension under load,, min | Elongation, in 4D, min | Hardness, internal | Remarks | ||
|---|---|---|---|---|---|---|
| ksi | MPa | ksi | MPa | % | HRB | |
| 85 | 586 | 45 | 310 | 12 | >80 inclusive | |
Size range: over 1″ to 2″ bars and rods inclusive
| Tensile strength, min | Yield strength, at 0.5% extension under load,, min | Elongation, in 4D, min | Hardness, internal | Remarks | ||
|---|---|---|---|---|---|---|
| ksi | MPa | ksi | MPa | % | HRB | |
| 80 | 552 | 42 | 290 | 12 | >80 inclusive | |
Size range: over 2″ to 3″ bars and rods inclusive
| Tensile strength, min | Yield strength, at 0.5% extension under load,, min | Elongation, in 4D, min | Hardness, internal | Remarks | ||
|---|---|---|---|---|---|---|
| ksi | MPa | ksi | MPa | % | HRB | |
| 75 | 517 | 35 | 241 | 15 | >80 inclusive | |
Physical properties
Physical properties provided by CDA | |||||||||||
| US Customary | Metric | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Melting point – liquidus | 1840 °F | 1004 °C | |||||||||
| Melting point – solidus | 1800 °F | 982 °C | |||||||||
| Density | 0.278 lb/in3 at 68 °F | 7.69 gm/cm3 at 20 °C | |||||||||
| Specific gravity | 7.69 | 7.69 | |||||||||
| Electrical conductivity | 8% IACS at 68 °F | 0.047 MegaSiemens/cm at 20 °C | |||||||||
| Thermal conductivity | 26 Btu/sq ft/ft hr/°F at 68 °F | 45 W/m at 20 °C | |||||||||
| Coefficient of thermal expansion 68-572 | 10 · 10-6 per °F (68-572 °F) | 17.3 · 10-6 per °C (20-300 °C) | |||||||||
| Specific heat capacity | 0.09 Btu/lb/°F at 68 °F | 377.1 J/kg at 20 °C | |||||||||
| Modulus of elasticity in tension | 16000 ksi | 110317 MPa | |||||||||
| Modulus of rigidity | 6000 ksi | 41369 MPa | |||||||||
Fabrication properties
Fabrication properties provided by CDA | |||||||||||
| Technique | Suitability | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Soldering | Not recommended | ||||||||||
| Brazing | Fair | ||||||||||
| Oxyacetylene welding | Not recommended | ||||||||||
| Gas shielded arc welding | Fair | ||||||||||
| Coated metal arc welding | Fair | ||||||||||
| Spot weld | Fair | ||||||||||
| Seam weld | Fair | ||||||||||
| Butt weld | Fair | ||||||||||
| Capacity for being cold worked | Poor | ||||||||||
| Capacity for being hot formed | Excellent | ||||||||||
| Forgeability Rating | 80 | ||||||||||
| Machinability rating | 60 | ||||||||||
Thermal properties
Thermal properties provided by CDA *Temperature is measured in Fahrenheit. | |||||||||||
| Treatment | Minimum* | Maximum* | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Annealing | 1100 | 1300 | |||||||||
| Hot treatment | 1300 | 1600 | |||||||||
Common fabrication processes
Forging, hot forming, machining
Common fabrication processes provided by CDA
