321 Stainless Steel - AMS 5510, AMS 5645

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321 SS (UNS S32100) is a titanium stabilized austenitic stainless steel that features improved resistance to intergranular corrosion. This grade is suitable for high-temperature applications up to 1500°F (815°C), where the addition of titanium stabilizes the material against chromium carbide formation. Since titanium has a stronger affinity for carbon than chromium, titanium carbide precipitates within the grain instead of forming at the grain boundaries. While corrosion resistance is similar to 304 and 304L in the annealed condition, it features higher creep and stress rupture properties, making it ideal for pressure vessels and boiler applications. 321 stainless steel is non-magnetic and heat resistant for continuous service at elevated temperatures.


321 Inventory Size Ranges

Sheet & Coil

0.010" - 0.125"

Sheet | Coil Quote
Plate

0.1875" - 0.250"

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Bar

0.375" - 9.000"

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Hex Bar

0.250” - 1.125”

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Custom Engineered Strip

0.0008" - 0.012"

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Working with 321 stainless

321 stainless materials cannot be hardened through heat treatment, only cold working. It is easily welded by all standard methods, and post-weld annealing is not required. This product is ductile and can be formed with ease. While corrosion resistance is generally excellent, especially against dilute organic acids, 321 SS is not suitable for chloride solutions, where it is susceptible to pitting and crevice corrosion. 

Machining 321 stainless

Alloy 321 is prone to work hardening and can be difficult to machine due to the addition of titanium – recommend rigid, powerful machining with minimal vibration and a quality lubricant, with tools kept sharp at all times.  Avoid interrupted cuts to prevent unnecessary work hardening.

Purchasing 321 stainless steel in sheet, coil, round bar, and hex bar

We are suppliers of 321 stainless steel sheet, coil, hex bar, and round bar stock in a variety of lengths and widths, and we can custom cut this material to your exact specifications. Our stainless steel coil can also be slit to your desired width.


Not finding what you are looking for? Connect with our sourcing group at sourcing@upmet.com


Standard Inventory Specifications

  • UNS S32100
  • UNS S32109
  • AMS 5510
  • AMS 5645
  • ASTM A 167
  • ASTM A 240
  • ASTM A 276
  • ASTM A 479
  • ASME SA 167
  • ASME SA 240

Other industry standards we comply with:

  • PWA-LCS
  • GE Aircraft Engine (GT193)
  • RR SABRe Edition 2
  • DFARS Compliant

Common Trade Names

  • ATI 321 (™ Allegheny Technologies)

Common Applications of 321

  • Useful in the chromium carbide precipitation range (800-1500°F, 427-815°C)
  • Aircraft exhaust stacks
  • Manifolds
  • Chemical processing equipment
  • Welded equipment
  • Jet engine parts
  • Heat Exchangers
  • Expansion joints
321 Chemical Composition
Element Percent by Weight
C Carbon 8.00%
Mn Manganese 200.00%
P Phosphorus 4.50%
S Sulfur 0.03
Si Silicon 75.00%
Cr Chromium 17.00-19.00
Ni Nickel 9.00-12.00
Ti Titanium 5x(C+N) min to 0.70 max
N Nitrogen 0.1
Fe Iron Balance

321 Physical Properties

 
Grade Density Modulus of Elasticity in Tension Melting Range
g/cm3 lb/in3
321 7.92 0.286 28 x 106 psi
193 GPa
1398-1446°C
2550-2635°F
347 7.96 0.288 28 x 106 psi
193 GPa
1398-1446°C
2550-2635°F

 

Mean Coefficient of Linear Thermal Expansion

Temperature Range Coefficients
°C °F cm/cm/°C in/in/°F
20-100 68-212 16.6 x 10-6 9.2 x 10-6
20-600 68-912 18.9 x 10-6 10.5 x 10-6
20-1000 68-1832 20.5 x 10-6 101.4 x 10-6

 

Thermal Conductivity

Temperature Range W/m·K Btu · in / hr · ft2 · °F
°C °F
20-100 68-212 16.3 112.5
20-500 68-932 21.4 147.7

 

Specific Heat

Temperature Range J/kg K Btu/lb · °F
°C °F
0-100 32-212 500 0.12

Magnetic Permeability

  • H/m Annealed
  • 1.02 Max

Electrical Resistivity

Temperature Range microhm·cm
°C °F
20 68 72
100 213 78
200 392 86
400 752 100
600 1112 111
800 1472 121
900 1652 126

Mechanical Properties and Yield Strength of 321

Mechanical Properties

Property Type 321 Type 347
Yield Strength, 0.2% Offset
psi
MPa
30,000
205
30,000
205
Ultimate Tensile Strength,
psi
MPa
75,000
515
75,000
515
Percent Elongation in 2 in. or 51 mm 40.0 40.0
Hardness, Max.,
Brinell (Plate)
RB (Sheet & Strip)
217
95
201
92

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.