Stainless Steel / 321/321 H ANN

321/321H is a general purpose austenitic stainless steel that is stabilized against carbide precipitation and designed to work within the carbide precipitation temperature range 427 to 816C (800 to 1500F). The H indicates a higher carbon content (0.04 0.10). It was developed for enhanced creep resistance and for higher strength at temperatures above 1000F (537C). The carbon content of the material enables dual certification listed as 321/321H. Alloy 321 cannot be hardened by heat treatment, only by cold working. It can be easily welded and processed by standard shop fabrication practices. It is non-magnetic in the annealed condition. The material is often used in Aerospace Piston Engine Manifolds, Chemical Processing, Expansion Joints, Food Processing, Petroleum Refining and Waste Treatment. (UNS S32100 & UNS S 32109)

Chemical Makeup

Element Min Max
Carbon, C 0.8
Manganese, Mn - 2
Silicon, Si - 1
Sulfur, S - 0.03
Phosphorus, P 0.04
Chromium, Cr 17 19
Nickel, Ni 8 12
Copper, Cu - 0.75
Molybdenum, Mo 3 0.75
Nitrogen, N - 0.1

Common Applications

  • Aerospace Aerospace
  • Industrial Industrial


  • Corrosion Resistance
  • Easily Welded
  • High Creep & Stress Rupture Properties
  • Good Low Temperature Toughness

We stock 321/321 H ANN to the following specifications:

  • AMS-5645
  • AMS-QQ-S-763
  • ASME-SA-479
  • ASTM-A-193 GRD B8T CL 1
  • ASTM-A-276
  • ASTM-A-320 GRD B8T CL 1 (EXC. FLTS)
  • ASTM-A-479
  • ASTM-A-484
  • QQS-763

Click on a cross-section to see the sizes we stock:

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