C31400
C31400 Leaded Commercial Bronze is a type of free-machining brass known for its exceptional electrical and thermal conductivity. This alloy also exhibits resistance to corrosion. Notably, it contains 2.00% lead, which imparts excellent free-cutting properties, making it well-suited for applications where ease of machining and good electrical and thermal conductivity are required.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 87.50 | 90.50 |
| Pb | 1.30 | 2.50 |
| Fe | – | 0.10 |
| Ni | – | 0.70 |
| Total Others | – | 0.40 |
| Zn | Remainder | |
MECHANICAL PROPERTIES ACCORDING TO C31400 ASTMB140 (AS PER TEMPER HO2)
| Range (Inch) | From | To | UTS Min (ksi) | PS Min (ksi) | Elongation Min (%) | Hardness Min | Hardness Max | |
| Round (Dia) | 0.059 | 0.500 | 50 | 30 | 7 | – | – | |
| 0.500 | 1.000 | 45 | 27 | 10 | – | – | ||
| 1.000 | 2.953 | 40 | 25 | 12 | – | – | ||
| Hex (A/F) | 0.118 | 0.500 | 50 | 30 | 7 | – | – | |
| 0.500 | 1.000 | 45 | 27 | 10 | – | – | ||
| 1.000 | 2.756 | 40 | 25 | 12 | – | – | ||
| Square (A/F) | 0.118 | 2.362 | 40 | 25 | 12 | – | – | |
| Rectangle | Thickness | 0.118 | 1.000 | 40 | 25 | 12 | – | – |
| Width | 0.157 | 2.000 | ||||||
| Thickness | 1.000 | 1.968 | 40 | 25 | 12 | – | – | |
| Width | 1.000 | 2.756 | ||||||
| Range (mm) | From | To | UTS Min (MPa) | PS Min (MPa) | Elongation Min (%) | Hardness Min | Hardness Max | |
| Round (Dia) | 1.5 | 12 | 345 | 205 | 7 | – | – | |
| 12 | 25 | 310 | 185 | 10 | – | – | ||
| 25 | 75 | 275 | 170 | 12 | – | – | ||
| Hex (A/F) | 3 | 12 | 345 | 205 | 7 | – | – | |
| 12 | 25 | 310 | 185 | 10 | – | – | ||
| 25 | 70 | 275 | 170 | 12 | – | – | ||
| Square (A/F) | 3 | 50 | 275 | 170 | 12 | – | – | |
| Rectangle | Thickness | 3 | 25 | 275 | 170 | 12 | – | – |
| Width | 4 | 50 | ||||||
| Thickness | 25 | 50 | 275 | 170 | 12 | – | – | |
| Width | 50 | 70 | ||||||
| PHYSICAL PROPERTIES | |
| Melting Point – Liquidus°F | 1900 |
| Melting Point – Solidus°F | 1850 |
| Density lb/cu in. at 68°F | 0.319 |
| Specific Gravity | 8.83 |
| Electrical Conductivity% IACS at 68°F | 42 |
| Thermal Conductivity Btu/ sq ft/ ft hr/ °F at 68°F | 104 |
| Coefficient of Thermal Expansion 68-57210⁻⁶ per °F (68 – 572°F) | 10.2 |
| Specific Heat Capacity Btu/ lb /°F at 68°F | 0.09 |
| Modulus of Elasticity in Tension ksi | 17000 |
| Modulus of Rigidity ksi | 6400 |
| FABRICATION PROPERTIES | |
| Technique | Suitability |
| Soldering | Excellent |
| Brazing | Good |
| Oxyacetylene Welding | Not Recommended |
| Gas Shielded Arc Welding | Not Recommended |
| Coated Metal Arc Welding | Not Recommended |
| Spot Weld | Not Recommended |
| Seam Weld | Not Recommended |
| Butt Weld | Fair |
| Capacity for Being Cold Worked | Good |
| Capacity for Being Hot Formed | Poor |
| Machinability Rating | 80 |
