Alro Steel was established in 1948 by Al and Robert Glick and has grown to include Alro Plastics, Alro Industrial Supply and Alro Metals Outlet.


Chemical Composition

Carbon 0.350
Manganese 0.800
Silicon 0.500
Molybdenum 0.450
Chromium 1.700

AISI P-20 Steel

AISI P20 Prehardened is a chrome-moly tool steel made specifically to fill the requirements for the machined cavities and forces used in zinc die casting and plastic molding. It is delivered fully quenched and tempered to approximately Brinell 300. Other hardness levels may be obtained through additional heat treatment. P20 composition and structure provide excellent machining and polishing characteristics.

  • Density: 0.284 lb/in3 (7861 kg/m3)
  • Specific Gravity: 7.86
  • Modulus of Elasticity: 30 x 106 psi (207 GPa)
  • Thermal Conductivity:
    24 Btu/ft/hr/°F
    41.5 W/m/°K
  • Machinability: 60-65% of a 1% carbon steel
Typical Uses
Die holders, Zinc die casting dies, Backers, Bolsters and Injection moulds.