ASTM A312 TP304 Stainless Steel Seamless Pipes, 304 Stainless Steel Pipes

What is 304 Stainless Steel?

304 (also known as UNS S30400, 1.4301, SUS304) is a widely used austenitic stainless steel, renowned for balancing corrosion resistance, formability and cost-effectiveness. Its chromium-nickel composition forms a dense passivation film on the surface, providing reliable protection in most common environments like fresh water and dry air.

 

Grade		C	Mn	Si	P	S	Cr	Mo	Ni	N
304	min.	-	-	-	-	-	18.0	-	8.0	-
	max.	0.08	2.0	0.75	0.045	0.030	20.0		10.5	0.10
304L	min.	-	-	-	-	-	18.0	-	8.0	-
	max.	0.030	2.0	0.75	0.045	0.030	20.0		12.0	0.10
304H	min.	0.04	-	-	-0.045	-	18.0	-	8.0	-
	max.	0.10	2.0	0.75		0.030	20.0		10.5

Equivalent Grades

304 stainless steel corresponds to: UNS S30400 (American standard), JIS SUS304 (Japanese standard), GB 06Cr19Ni10 (Chinese standard) and EN X5CrNi18-10 (European standard).

 

Chemical Composition (wt%)

Carbon ≤0.08, Silicon ≤1.00, Manganese ≤2.00, Phosphorus ≤0.045, Sulfur ≤0.030, Chromium 18.00-20.00, Nickel 8.00-10.50, Nitrogen ≤0.10, Iron (balance).

 

Key Properties (20°C, Annealed Condition)

Physical properties: Density 7.93g/cm³, melting point 1400-1450°C.Mechanical properties: Tensile strength 515-690N/mm², 0.2% yield strength ≥205N/mm², elongation ≥40%, hardness ≤201HB.

 

Core Characteristics

Corrosion resistance: Excellent in fresh water, dry air and weak acids, but less resistant to high-chloride environments compared to 316.

Formability & weldability: Suitable for bending, stamping and welding without preheating.

Cost-effectiveness: The first choice for general civilian and industrial applications with moderate corrosion requirements.

Hardness & Density

Hardness: ≤201HB in annealed state; cold working can increase hardness (up to 300HB), and annealing (1050-1100°C) restores ductility.

Density: 7.93g/cm³, consistent with other austenitic stainless steel grades.

Difference Between 304 and 304L

The core difference is carbon content: 304 (≤0.08%) vs 304L (≤0.03%). 304L avoids intergranular corrosion after welding without heat treatment but has slightly lower tensile strength (485-650N/mm²). 304 is preferred for non-welding, cost-sensitive scenarios, while 304L suits welding-intensive applications.

 

304 Stainless Steel Suppliers

If you have project requirements for 304 stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.