CZ121PB4
CZ121Pb4, classified as Free cutting brass, stands as a notably enhanced variation of 60/40 brass, acclaimed for its outstanding free cutting characteristics. Its application lies in the high-volume production of brass components necessitating utmost output and prolonged tool lifespan. This is particularly relevant in scenarios where no subsequent cold forming is needed following the machining process.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 56.50 | 58.50 |
| Pb | 3.50 | 4.50 |
| Fe | – | 0.30 |
| Total Others | – | 0.70 |
| Zn | Remainder | |
MECHANICAL PROPERTIES ACCORDING TO BS2874 (AS PER TEMPER M)
| Range (mm) | From | To | UTS Min (N/mm²) | PS Min | Elongation (%) | Hardness Min | Hardness Max | |
| Round (Dia) | 2 | 18 | 425 | – | 15 | – | – | |
| 18 | 40 | 400 | – | 18 | – | – | ||
| 40 | 75 | 380 | – | 20 | – | – | ||
| Hex (A/F) | 3 | 18 | 425 | – | 15 | – | – | |
| 18 | 40 | 400 | – | 18 | – | – | ||
| 40 | 70 | 380 | – | 20 | – | – | ||
| Square (A/F) | 3 | 18 | 425 | – | 15 | – | – | |
| 18 | 40 | 400 | – | 18 | – | – | ||
| 40 | 60 | 380 | – | 20 | – | – | ||
| Rectangle (Thickness) | 3 | 18 | 425 | – | 15 | – | – | |
| 18 | 40 | 400 | – | 18 | – | – | ||
| 40 | 50 | 380 | – | 20 | – | – | ||
| PHYSICAL PROPERTIES | |
| Melting Point – Liquidus°F | 1630 |
| Melting Point – Solidus°F | 1610 |
| Densitylb/cu in. at 68°F | 0.306 |
| Specific Gravity | 8.47 |
| Electrical Conductivity% IACS at 68°F | 28 |
| Thermal ConductivityBtu/ sq ft/ ft hr/ °F at 68°F | 71 |
| Coefficient of Thermal Expansion 68-57210⁻⁶ per °F (68 – 572°F) | 11.6 |
| Specific Heat CapacityBtu/ lb /°F at 68°F | 0.09 |
| Modulus of Elasticity in Tensionksi | 14000 |
| Modulus of Rigidityksi | 5300 |
| 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 | Poor |
| Capacity for Being Hot Formed | Excellent |
| Machinability Rating | 90 |
