Postalloy® 2521-MCG

Postalloy® 2521-MCG is a cobalt base hardfacing alloy offering good strength and toughness at elevated temperatures up to 1500 °F (816 °C), and is used for weld overlaying of hot-working dies and valves. A low carbon content weld deposit with dispersed hard carbides provide excellent resistance to thermal shock, galling, corrosion, and cavitation erosion. These deposits are strengthened by the addition of molybdenum and are very stable in thermal cycling environments.

  • Weld deposits exhibit superior resistance to heat checking, spalling and chipping.
  • Excellent resistance to corrosive environments, and outstanding resistance to cavitation, erosion and thermal shock.
  • Resists oxidizing and reducing atmospheres up to 2100 °F (1149 °C).
  • Postalloy® 2521-MCG also provides excellent resistance to corrosive environments.


Product Type

  • Metal-cored
  • Gas-shielded
  • Cobalt Base Hardfacing Alloy


  • Forging Dies, Hot trimming dies, Extrusion dies, Hot shear blades, Cavitation repair, Steam and fluid control valve bodies and seats and Seamless pipe piercing mandrels.

Weld Deposit Properties

Hardness as Welded:
Work-hardens Over:
Excellent work-hardening properties
Deposits have very little tendency to relief check and are fully machinable

Welding Parameters

Current Type: DC Electrode Positive

Volts Amps Diameter Gas Stick Out
16-24 80-225 .045" (1.2mm) Ar/CO2 3/4" (19mm)
16-24 80-225 1/16" (1.6mm) Ar/CO2 3/4" (19mm)

Welding Procedure:

Packaging Options

Diameter Standard Packaging
.045" (1.2mm) 5 lb (2.27kgs) spool, 25 lb (11.30kgs) spool
1/16" (1.6mm) 5 lb (2.27kgs) spool, 25 lb (11.30kgs) spool