UNS: S30403
EN-DIN: 1.4306
Industries supplied include: Process equipment in mining, chemical, cryogenic, food, dairy, and pharmaceutical industries. 304 grade stainless has excellent welding and formability characteristics and is one of the most utilized stainless steels. 304L is an extra low carbon grade with a 0.03% max carbon content that eliminates carbide precipitation due to welding.
The Chemical Composition and Mechanical Properties of the most common variants of Type 304 are as follows:
| Type 304 | Type 304L | Type 304H | |
| ASTM A240/A240M (UNS Designation) | S30400 | S30403 | S30409 |
Chemical Composition | |||
Chromium | 17.5-19.5% | 17.5-19.5% | 18.0-20.0% |
Nickel | 8.0-10.5% | 8.0-12.0% | 8.0-10.5% |
Carbon (max.) | 0.070% | 0.030% | .040-.100% |
Manganese (max.) | 2.000% | 2.000% | 2.000% |
Silicon (max.) | 0.750% | 0.750% | 0.750% |
Sulfur (max.) | 0.030% | 0.030% | 0.030% |
Phosphorus (max.) | 0.045% | 0.045% | 0.045% |
Nitrogen (max.) | 0.100% | 0.100% | |
Mechanical Properties (annealed) | |||
Tensile (min. psi) | 75,000 | 70,000 | 75,000 |
Yield (min. psi) | 30,000 | 25,000 | 30,000 |
Elongation (in 2″, min %) | 40 | 40 | 40 |
Hardness (max Rb) | 92 | 92 | 92 |
T304, type 304 and grade 304 are interchangeable terms for 304 stainless steel.
T304L, type 304L and grade 304L are interchangeable terms for 304L stainless steel.
T304H, type 304H and grade 304H are interchangeable terms for 304H stainless steel.
Physical Properties At 70°F (At 20°C)
Density
0.29 lb./in3 / (8.03 g/cm3)
Modulus of Elasticity (E)
28.0 x 103 ksi / (193 x 103MPa)
Coefficient of Expansion
9.4 x 10-6 microinches/in.-°F (70-600°F) / (16.9 μm/m-°C) (20-300°C)
Electrical Resistivity
28.4 μ ohm.in / (72 μ ohm.cm)
Thermal Conductivity
9.4 Btu-in./ft.2hr.-°F / (16.2 W/m-K)
