PolyStel 21 – Cobalt Alloy 21


PolyStel 21 has excellent resistance to many forms of chemical and mechanical degradation over a wide temperature range. PolyStel 21 is an excellent alloy for corrosion resistance, galling, cavitation, and metal to metal wear resistance. PolyStel 21 products are equivalent in nominal chemical compositions, physical properties, and performance properties to the Stellite brand. PolyStel 21 products meet the requirements of AWS A 5.21 ERCCoCr-E, ERCoCr-E, and ECoCr-E.

PolyStel 21 GMAW micrograph at 1000X

PolyStel products are manufactured and sold by Polymet Corporation. Stellite brand products manufactured and sold by Kennametal, Inc. are not affiliated and Kennametal does not endorse PolyStel products.

Product Details

Characteristics and Composition

Ni Co Fe Cr W Mo Al Si
BAL 29 5
Mn Nb Ti Ta Zr C Other
Rockwell Hardness
HRC 30-35

Product Forms

.012″ – .157″ (0.30mm – 4mm)