904L Stainless Steel

904L stainless steel is a high-alloy austenitic steel composed primarily of iron, nickel, chromium, and molybdenum, with additions of manganese and copper.

This grade contains 19–23% chromium and 23–28% nickel—significantly higher than standard grades such as 304 and 316—giving it superior corrosion resistance in aggressive environments.

The “L” in its name denotes a low carbon content, which enhances weldability and reduces the risk of intergranular corrosion after welding.

A key feature of 904L is its 1–2% copper content, which provides excellent resistance to reducing acids like sulfuric acid. Combined with 4–5% molybdenum, the alloy also offers enhanced resistance to pitting and crevice corrosion, making it ideal for demanding applications in chemical processing, marine, and pollution control industries.

904L Stainless Steel Chemical Analysis

Weight Percentage

Nickel	23.0 min. to 28.0 max.
Silicon	1.00
Chromium	19.0 min. To 23.0 max.
Phosphorus	0.045
Molybdenum	4.0 min. To 5.0 max.
Sulfur	0.035
Copper	1.0 min. To 2.0 max.
Iron	Balance
Manganese	2.00

(Room Temperature)

Thermal Conductivity	11.5	W.m -1.°K-1
Thermal Expansion	15.8	μm/μm/°C
Specific Heat (0-100°C)	450	J.kg-1.°K-1
Density	7.95	g/cm3
Electrical Resistivity	9.52	μohm/cm
Modulus Elasticity	190	GPa

Temper	Annealed
Tensile Rm	490	MPa (min)
Tensile Rm	71	ksi (min)
Elongation (2” or 4D gl)	35	% (min)
R.p. 0.2% Yield	220	MPa (min)
R.p. 0.2% Yield	32	ksi (min)