Stellite 21
Stellite® 21 (UNS R30021, originally Stellite 8) is a cobalt-chromium-molybdenum alloy - its ternary element is molybdenum, not tungsten - so it carries a lower volume of carbides and lets the cobalt matrix govern behaviour. That gives excellent cavitation, galling and metal-to-metal sliding wear resistance, strong thermal and mechanical shock resistance, and better resistance to reducing and complex environments (sulphuric and hydrochloric acid, sour gas) than the tungsten grades, held in oxidising service to about 1150 °C. It work-hardens in service, and its biocompatibility made it an early hip-implant and dental alloy. Typical uses are valve trim for petrochemical and power generation, forging and hot-stamping dies, and high-temperature wear parts.
Available Forms
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | R30021 |
| Density | 8.33 g/cm3 |
| Melting range | 1295-1435 °C |
Identifiers and physical constants for Stellite 21. A dash means no such designation is published for this grade.
Aurico Alloys LLP supplies Stellite 21 across the forms above with material test certificates (EN 10204 3.1) and export-ready packaging from Mumbai, India. Chemistry and mechanical data for each product form are on the form pages linked above. Contact us for stock availability and pricing.