Type 304H Stainless Steel

Unlike 304L, Type 304H has a higher carbon content making the steel more suitable for use in applications where elevated temperatures are present. It is an austenitic chromium-nickel steel alloy and the greater carbon content delivers an increased tensile and yield strength.

The material is recommended for use in ASME pressure vessels in working service above 525 °C due to the grade’s heat resistant properties.

Benefits of using 304H Stainless Steel

  • Higher carbon content gives the material greater heat resistant qualities
  • Higher tensile yield strength
  • Greater short and long term creep strength

304H alloy is commonly found in the oil refining, gas and chemical industry and is used in industrial boilers, pressure vessels, heat exchangers, pipelines and condensers. The material is also used throughout the power generation industry.

Mechanical Properties of 304H

Description Type 304H
Proof Stress 0.2% (MPa) 205
Tensile strength (MPa) 515
Elongation A5 (%) 40
Hardness HB: 201
HRB: 92

Chemical Composition of 304H

UNS No S30409
EN 1.4948
Carbon (C) 0.04/0.10
Silicon (Si) 0.75
Manganese (Mn) 2.00
Phosphorus (P) 0.045
Sulphur (S) 0.030
Chromium (Cr) 18.00 – 20.00
Molybdenum (Mo)
Nickel (Ni) 8.00 – 10.50
Nitrogen (N)