Stainless Steel Grade 334 (UNS S33400)

Topics Covered

Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties


Stainless steel grade 334 is a titanium and aluminum based austenitic stainless steel. This alloy provides better temperature scaling resistance than chromium-nickel stainless steels such as grade 304. It also has good oxidation resistance of up to 1038°C (1900°F). Grade 334 is commonly used as a sheathing material.

The following sections will discuss in detail about stainless steel grade 334.

Chemical Composition

The chemical composition of stainless steel grade 334 is outlined in the following table.

Element Content (%)
Nickel, Ni 19-20
Chromium, Cr 19-19.5
Manganese, Mn 1
Silicon, Si 0.75
Phosphorus, P 0.02
Sulfur, S 0.015
Titanium, Ti 0.4
Aluminum, Al 0.4
Copper, Cu 0.2
Carbon, C 0.03
Iron, Fe Balance

Physical Properties

The physical properties of stainless steel grade 334 are tabulated below.

Properties Metric Imperial
Density 8.03 g/cm3 0.290 lb/in3

Mechanical Properties

The following table shows mechanical properties of stainless steel grade 334.

Properties Metric Imperial
Tensile strength 572.4 MPa 83020 psi
Yield strength 241.4 MPa 35010 psi
Modulus of elasticity 200 GPa 29000 ksi
Elongation at break 40% 40%
Hardness, Rockwell B 82 82

Thermal Properties

The thermal properties of stainless steel grade 334 are tabulated below.

Properties Metric Imperial
Thermal expansion co-efficient (@20-100°C/68-212°F) 17.04 µm/m°C 9.467 µin/in°F
Thermal conductivity 12.9 W/mK 89.5 BTU in/hr.ft².°F


Stainless steel grade 334 can be applied in these areas:

  • Automotive exhaust systems
  • Sheathing material for heating elements
  • Emission control systems
  • In applications where resistance to high temperature degradation is essential

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