FREE MACHINING BRASS
Metals
Brass
Bronze
DESCRIPTION
CZ121PB4
SPEC SHEET
CZ121Pb4, Free cutting brass, is a significantly improved form of 60/40 brass, with excellent free cutting properties. It is used in the mass production of brass components where maximum output and longest tool life are required, and where no further cold forming after machining is required.
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 |
TYPICAL USES
- Architecture
- Builders Hardware
- Consumer
- Industrial
- Ordnance