Alloy 304 • UNS S30400 • WNR 1.4301

Alloys 304 (S30400) and 304L (S30403) stainless steels are variations of the 18 percent chromium – 8 percent nickel austenitic alloy, the most familiar and most frequently used alloy in the stainless steel family.

High strength, excellent corrosion resistance and minimized carbon content make Alloy 304 and 304L Stainless Steels useful for applications where welding is required. Uses include architectural mouldings and trim, welded components of chemical, textile, paper, pharmaceutical and chemical industry processing equipment.

Other advantages are its resistance to oxidation, excellent formability, ease of fabrication and cleaning, excellent strength to weight ratio and good toughness at cryogenic temperatures.

For severely corrosive environments,the lower content of Type 304L is preferred because of its greater immunity to intergranular corrosion.

Available tube product forms

Typical Applications

Typical manufacturing specifications

  • AMS 5566
  • AMS 5569
  • AMS5647
  • AMS 6845
  • BS 10216 Pt 5
  • ASTM A213
  • ASTM A269
  • ASTM A312
  • ASTM A632
  • BS 3605 Pt 1
  • NFA 49-117
  • NFA 49-217
  • Mil-T 8504
  • Mil-T 8606
  • Also individual customer specifications.

Industries predominantly using this grade            

Technical Data

Mechanical Properties

Temper 304 304L
Tensile Rm 76 ksi (min) 70 ksi (min)
Tensile Rm 517 MPa (min) 485 MPa (min)
R.p. 0.2% Yield 31 ksi (min) 25 ksi (min)
R.p. 0.2% Yield 207 MPa (min) 170 MPa (min)
Elongation (2" or 4D gl) 40 % (min) 40 % (min)


Physical Properties (Room Temperature)

Specific Heat (0-100°C) 500 J.kg-1.°K-1
Thermal Conductivity 16.2 W.m -1.°K-1
Thermal Expansion 17.2 mm/m/°C
Modulus Elasticity 19.3 GPa
Electrical Resistivity 7.23 μohm/cm
Density 8.0 g/cm3


Chemical Composition (% by weight)

  304 304L
Element Min Max Min Max
C - 0.08 - 0.08
Mn - 2 - 2
Ni 8 10.5 8 12.0
Cr 18 20 18 20
S - 0.03 - 0.03
N - 0.1 - 0.1
Si - 0.75 - 0.75
P - 0.045 - 0.045
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