How to tell if stainless steel is 304

How to Tell if Stainless Steel is 304

What is Stainless Steel 304?

Stainless steel 304 is a widely used austenitic alloy, known as sa 240 304 material or UNS S30400, prized for its corrosion resistance, formability, and strength. It contains 18% chromium and 8% nickel, making it non-magnetic in its annealed state (ss 304 non magnetic). Specified under ASME SA240 and ASTM A240, it’s ideal for applications like sa 240 gr 304 plate in chemical tanks or sa 240 gr 304 pipe in food processing. Identifying 304 is critical to ensure it meets project requirements, especially when compared to grades like 316 or 201. Gangsteel, a leading manufacturer and exporter in China, supplies certified 304 stainless steel compliant with ASME SA240 stainless steel plates. This guide details methods to confirm if stainless steel is 304, incorporating keywords like ss 304 plate density and sa-240 304l material.

Method 1: Magnet Test for Non-Magnetic Properties

304 stainless steel is typically ss 304 non magnetic due to its austenitic structure. To test:

• Procedure: Clean the surface of the material (e.g., sa 240 304 plate) and place a strong neodymium magnet on it. If the magnet doesn’t stick or only weakly attracts, it’s likely 304. If it sticks firmly, it’s probably a magnetic grade like 430.
• Limitation: Cold working (e.g., bending sa240 304 stainless) can induce slight magnetism due to martensite formation, so this test isn’t definitive.
• Relevance: Useful for distinguishing sa-240-304 material from ferritic or martensitic steels but not from 316, which is also non-magnetic.

Method 2: Molybdenum Spot Test for Chemical Composition

304 lacks molybdenum, unlike 316, which has 2-3%. A chemical spot test can differentiate:

• Procedure: Apply a molybdenum test solution (available from industrial suppliers) to a clean surface of materiale sa 240 304 or sa 240 304l material. No color change after 1-2 minutes indicates 304 (or 304L). A yellow or green hue suggests molybdenum, pointing to 316.
• Accuracy: Highly reliable for sa 240 type 304 304l vs 316, but requires proper chemical handling.
• Relevance: Essential for applications like sa 240 gr 304 pipe where chloride resistance matters.

Method 3: Spark Test for Visual Identification

Grinding stainless steel produces distinct spark patterns:

• Procedure: Use a bench grinder on sa 240 304 material or plat stainless 304. 304 produces long, thin, orange sparks with few forks due to low carbon (≤0.08%). Ferritic steels like 430 produce bushy, bright sparks.
• Limitation: Requires experience to differentiate from 316, which has similar sparks but denser due to molybdenum.
• Relevance: Useful in workshops for quick checks on sa 240 gr 304 plate or plat ss 304 3 mm.

Method 4: Chemical Composition Analysis

For precise identification, use spectrometry (XRF or OES):

• Procedure: Analyze the alloy content of sa240-304 material. 304 has 18-20% Cr, 8-10.5% Ni, and no molybdenum. Compare with 316 (2-3% Mo) or 201 (lower Ni, higher Mn).
• Accuracy: Lab-grade accuracy for sa 240 304h material or sa 182 f304 material.
• Relevance: Ideal for critical applications like sa 240 gr 304/304l in pressure vessels.

Method 5: Check Certification and Labeling

Verify documentation or markings:

• Procedure: Look for labels like AISI 304, UNS S30400, or EN 1.4301 on sa240 304l material. Mill test certificates (MTCs) from suppliers like Gangsteel confirm specs for sa 240 tp 304/l.
• Accuracy: Most reliable if documentation is available.
• Relevance: Essential for compliance in sa 240 304 steel or sa 240 304 plate projects.

Physical Properties: Density and Hardness

Check physical properties to narrow down:

• Density: ss 304 plate density and sa 240 304l density are 7.93 g/cm³. Measure with a density meter to rule out other alloys.
• Hardness: 304 has a maximum hardness of 201 HBW or 92 HRB, tested with a Brinell or Rockwell tester.
• Relevance: Useful for sa240-304 a240-304 or sa240 304 stainless in structural design.

Price and Market Considerations

Ss sheet 304 price, ss 304 steel price, ss 304 sheet price, and 304 ss plate price range from $1,820 to $3,584 per metric ton in October 2025. Gangsteel offers competitive rates for sa240-304 material and sa 240 gr 304 means applications.

Why Choose Gangsteel for Stainless Steel 304?

Gangsteel provides 304 with:

• Quality Compliance: Meets ASME SA240 and ASTM A240 standards.
• Customization: Sizes like plat ss 304 3mm for specific needs.
• Global Delivery: Fast shipping for sa 240 304 density projects.
• Variety: Including SA240 Gr 347 and SA240 Gr 904L.

Conclusion

Identifying stainless steel 304 involves magnet tests, molybdenum tests, spark tests, or chemical analysis. For what is sa 240 304 or what is 240 steel, it’s a reliable austenitic alloy. Gangsteel’s solutions ensure quality for sa240 type 304 needs. Contact for UNS stainless steel plates.

FAQ

What is SA 240 304 stainless steel?

What is sa 240 304refers to ASME SA240 Grade 304, an austenitic stainless steel with excellent corrosion resistance and formability, used in sa 240 gr 304 plate.

How does 304 differ from 316 stainless steel?

Ss204 vs ss 304shows 304 has higher nickel for better corrosion resistance; 316 has molybdenum for chloride environments.

What is the density of 304 stainless steel?

Ss 304 plate densityand sa 240 304 density are 7.93 g/cm³, used for weight calculations in sa 240 304 plate designs.

Is 304 stainless steel non-magnetic?

Yes, ss 304 non magnetic in annealed form, but cold working may induce slight magnetism in sa-240-304 material.

What is the price of 304 stainless steel?

Ss sheet 304 priceand 304 ss plate price range $1,820-$3,584/MT as of October 2025, varying by region.

How does 304L compare to 304?

Sa 240 304l materialhas lower carbon (≤0.03%) for better weldability than 304 (≤0.08%), ideal for sa 240 tp 304/304l welded structures.

What is SA240 material used for?

What is SA240is the ASME standard for stainless steel like sa240 material, used in sa240 304l material for tanks and piping.

Can a spark test distinguish 304 from other grades?

Yes, 304 produces thin, orange sparks with few forks, unlike ferritic grades, useful for sa240 grade 304 identification.