CZ128

CZ128 is a machining brass which combines the contrasting material Properties of machining and cold working exceptionally well. This material is therefore well established in various industries as the standard alloy for machining and cold Working.


CHEMICAL COMPOSITION
Elements Min (%) Max (%)
Cu 58.50 61.00
Pb 1.50 2.50
Fe - 0.20
Total Others - 0.50
Zn Remainder

Mechanical Properties According To BS2874 (As Per Temper M)
Range (mm) From To UTS Min (N/mm²) UTS Max (N/mm²) PS Min (N/mm²) Elongation Min (%) Hardness Min Hardness Max
Round (Dia) 6 18 380 - - 22 - -
18 40 380 - - 22 - -
40 75 350 - - 25 - -
Hex (A/F) 6 18 380 - - 22 - -
18 40 380 - - 22 - -
40 70 350 - - 25 - -
Square (A/F) 6 18 380 - - 22 - -
18 40 380 - - 22 - -
40 60 350 - - 25 - -
Rectangle Thickness 6 18 380 - - 22 - -
Thickness 18 40 380 - - 22 - -
Thickness 40 50 350 - - 25 - -

PHYSICAL PROPERTIES
Density 8.44 g/cm³
Electrical Conductivity % IACS at 68°F 24
Thermal Conductivity BTU/ sq ft/ ft hr/ °F at 68°F 109 W/m K
Thermal expansion coefficient 20.4 10-6/K
Modulus of Elasticity 102 Gpa
FABRICATION PROPERTIES
Technique Suitability
Machinability (CuZn39Pb3 = 100 %) 90%
Capacity for Being Cold Worked Fair
Capacity for Being Hot Worked Excellent
Resistance welding (butt weld) Good
Inert gas shielded arc welding Poor
Gas welding Poor
Hard soldering Fair
Soft soldering Excellent
Melting range 895-900 °C
Hot working 650-750 °C
Soft annealing 450-650 °C (1–3 hr)
Thermal stress relieving 200-300 °C (1-3 hr)

TYPICAL USES
  • Furniture
  • Window fittings
  • Valve
  • Valve parts
  • Decorative metalwork
  • Clock and instrument
  • Castings
  • Gears
  • Cams
  • Fasteners