Postalloy® 21 Flux-coated Electrode

Postalloy® 21 is a self-hardening wear resistant overlay engineered for abrasion and abrasion combined with medium impact. The alloy chemistry provides good resistance to spalling and chipping while the special low hydrogen coating minimizes dilution and helps to eliminate under-bead cracking. Use on carbon and low alloy steels.


Product Type

  • Flux-coated Electrode


  • Excavator Parts and Bucket Teeth
  • Tamping Tools
  • Screw Conveyers
  • Elevator Bucket Lips
  • Dozer and graber blades.
  • Post hole augersWear areas on clam shell buckets
  • Mining Drag line and shovel buckets
  • Earth moving and construction equipment
  • Muller tires
  • Grader end bits

Weld Deposit Properties

Also available as a semi-automatic wire - DuraHard™ 2898-MCG or 2898-FCO
Hardness as deposited:
Non-cracking with proper preheat and post heat procedures
Machinability - Best by grinding or machining with special tooling
Deposit Thickness:
Unlimited layers with proper procedures

Welding Parameters

Current Type: DC Electrode Positive , DC Electrode Negative AC

Amps Diameter
90-135 1/8" (3.2mm)
130-160 5/32" (4mm)
150-225 3/16" (4.8mm)

Welding Procedure:

Due to lower Dilution. DC Electrode Negative will produce a higher first pass hardness and is also ideal for thin sections. Remove all damaged or fatigued metal. Preheating is generally not required. However, for high carbon or ally steels and cast iron, a preheat of approximately 400 °F (204 °C) is recommended. Maintain a short to medium arc using a weave technique. Remove slag.

Packaging Options

Diameter Standard Packaging
1/8" (3.2mm) Resealable Plastic Box
5/32" (4mm) Resealable Plastic Box
3/16" (4.8mm) Resealable Plastic Box