How to Identify Genuine 904L Stainless Steel by Standard Code?

When sourcing stainless steel for chemical, marine, or high-corrosion environments, 904L stainless steel (UNS N08904 / 1.4539) is a premium choice. However, due to its high nickel and molybdenum content, some suppliers may mix it with cheaper grades like 316L or 317L. To avoid costly mistakes, buyers must know how to identify genuine 904L stainless steel by standard codes.

 

Standard Codes for 904L Stainless Steel

	904L (UNS N08904)	ASTM B625 (plate), ASTM B677 (tubing), ASTM B673 (pipe)
	1.4539	X1NiCrMoCu25-20-5
	W.Nr. 1.4539	–
	SUS 890L
	X1NiCrMoCu25-20-5	–

in the material test certificate (MTC), the product may not be genuine 904L.

Corrosion Resistance: Withstands stress-free corrosion in a 40% calcium chloride solution for 1000 hours. Stable in pure sulfuric acid below 40℃ and pure phosphoric acid below 85% concentration.
Mechanical Properties: Tensile strength >= 490 MPa, yield strength >= 215 MPa, elongation >= 35%.
If the material meets both the above standard codes and chemical composition characteristics, it can be confirmed as genuine 904L stainless steel.

 

What is the difference between 904L and 316L in standard code?

316L → ASTM A240 / UNS S31603 / EN 1.4404

904L → ASTM B625 / UNS N08904 / EN 1.4539
 

Can 904L be replaced by cheaper stainless steel?

Not always. 316L and 317L cannot match 904L's resistance to sulfuric acid and seawater chloride corrosion.

 

Why is 904L stainless steel more expensive?

Because it contains very high Nickel + Molybdenum + Copper, making it much costlier than 304/316 but with superior performance in aggressive environments.

 

Which ASTM standards cover 904L products?

ASTM B625 → Plate & Sheet

ASTM B677 → Tubing

ASTM B673 → Pipe

ASTM A182 → Forged fittings & flanges

 

Need 904L stainless steel? Feel free to place your order with GNEE! We stock a large selection of popular products in stock, processed into a variety of practical forms, including plates, coils, tubes, bars, and wire. For detailed chemical composition information or free samples, please contact our factory today. All stocked plates, tubes, coils, and accessories strictly comply with ASTM, EN, and JIS standards and are ISO, SGS, and BV certified, with full traceability (EN 10204 3.1 MTC). We also offer custom processing services (cutting, bending, welding, and polishing).