321H Stainless Steel Plate - UNS S32109

321H is a widely used stainless steel, where parts are heated within carbide-precipitation temperature range (800°F-1500°F) and exposed to corrosive atmosphere.  321H is similar to 304, but with higher nickel content and stabilized with titanium. Titanium preferentially reacts with carbon in the steel and prevents precipitation of chromium carbides at the grain boundaries, thus preserving corrosion-resistant properties by preventing depletion of chromium near the grain boundaries during exposure within critical temperature range. This grade responds well to hardening by cold working. It has good welding characteristics; and post-weld annealing is not normally required to restore its excellent performance in a wide range of corrosive conditions. 

United Performance Metals supplies 321H stainless steel plate in a variety of lengths and widths and can custom cut to your exact specifications.


Standard Industry Specifications 

  • UNS S32109
  • ASTM A 240
  • GE-S400/1000
  • RR SABRe Edition 2
  • DFARS Compliant

Common Trade Names

  • ATI 321 (™ Allegheny Technologies)

Common Applications of 321H Stainless Steel

  • Heat exchangers 
  • Aircraft industry 
  • Fabrication industry 
  • High temperature chemical process equipment
  • Refinery industry equipment oil refineries 

Inventory Size Range

  • Plate : 0.007" - .500"

Please contact us for more details.

The technical data provided is for information only and not for design purposes. It is not warranted or guaranteed.

321H Chemical Composition

Element Percent by Weight
Chromium 17.0 - 19.0
Manganese 2.0 Maximum
Silicon 0.75 Maximum
Nickel 9.0 - 12.0
Phosphorus 0.045 Maximum
Sulfur 0.030 Maximum
Carbon 0.080 Maximum
Nitrogen 0.1 Maximum
Titanium 5 (C+N) - 0.700


321H Physical Properties

  • Density: 7.9 kg/m3
  • Melting Range: 1400 - 1450°C
Specific Heat Capacity 500 J/kgK
Thermal Conductivity (@100°C) 16.2 [W/mK]
Modulus of Elasticity 193


Mechanical Properties and Yield Strength of 321H

Yield Strength, ksi 30
Tensile strength, ksi 75
Elongation, % 40
Hardness [HRB] 95


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