Postalloy® 2521-E Flux-coated Electrode

Postalloy® 2521-E 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-E also provides excellent resistance to corrosive environments.


Product Type

  • Cobalt Base Hardfacing Electrode


  • Hot shears, Cavitation repair, chemical and petrochemical valves, Forging dies, Steam valves and Seamless pipe piercing mandrels.

Weld Deposit Properties

Work-hardens Up To:
Excellent work-hardening properties
Deposit Thickness:
2 layers
30Rc - 30Rc

Welding Parameters

Current Type: DC Electrode Positive

Volts Amps Diameter
15-25 50-70 3/32" (2.4mm)
15-25 80-110 1/8" (3.2mm)
15-25 120-150 5/32" (4mm)
15-30 150-180 3/16" (4.8mm)

Welding Procedure:

Packaging Options

Diameter Standard Packaging
All Diameters 10 lb (4.54kgs) tubes