Alloy 347 exhibits excellent resistance to intergranular corrosion.

Alloy 347 from NeoNickel offers superior resistance to intergranular corrosion. It’s also suitable for high temperature service, due to its good mechanical properties. Alloy 347 is now available from NeoNickel Hranice.

  • UNS Number: UNS S34700
  • AMS: 5512, 5646, 5680

Product availability

Round Bar
Welding Wire

Chemical analysis



  • Oil Refineries
  • Fluid catalytic cracking units
  • Hanger rods
  • Recuperator tube sheets
  • Fired heater tubes
  • Equipment in and around reactors

About Alloy 347

Alloy 347 is generally used where corrosive conditions are severe, such as aircraft exhaust stacks, manifolds and ring collectors. Type 347 is also used for heavy welded assemblies which cannot be annealed after welding or where the operating conditions cause exposure within the temperature range between 426.67° to 815.55°F.

  • Density: 7.916 g/cm³
  • Electrical resistivity: 8.89 x 10^ -7 Ωm

Mechanical & Physical Properties

Mechanical & Physical Properties21.1°C100°C500°C
Coefficient of Thermal Expansion, µm/m⁰C16.6
Thermal Conductivity/ kcal/(hr.m.°C)167.4219.8
Modulus of Elasticity Dynamic/ x105 MPa1.93

Minimum Specified Properties, ASTM A240

75Tensile strength, ksi
300.2% Yield Strength, ksi
40Elongation, %
201Hardness Max, Brinell

Typical Tensile and Impact Properties

Temperature, °C20°C204.44°C426.66°C537.77°C648.88°C732.22°C815.55°C
Ultimate Tensile Strength, ksi93.373.669.563.552.339.326.4
0.2% Yield Strength, ksi36.536.629.727.424.522.818.6
Proud members of the British Valve & Actuator AssociationProud members of the British Valve & Actuator Association