Type 304 Square Tubes

Type 304 is the most common austenitic stainless steel, with 18% chromium and 8% nickel for superior resistance to oxidation and corrosion. Its non-magnetic properties in the annealed condition and excellent formability make it highly versatile. This grade delivers a good balance of strength, toughness, and fabrication characteristics - a reliable choice for structural and decorative projects where environmental exposure is a concern.

The square tube shape provides structural efficiency for frames, supports, and posts, offering high strength-to-weight ratios and clean aesthetic lines. It's easily welded, cut, and formed, simplifying fabrication for handrails, support columns, and machine frames. Available in standard mill finish or polished 180 grit satin finish for architectural applications, it adapts to both functional and cosmetic requirements.

Our Quality Guarantee

Every order of 304 square tubes comes with full traceability. We provide MTR (Mill Test Report) with chemical composition and mechanical properties for each batch. Our defect rate has been under 0.02% over the past 3 years — if any tube fails to meet ASTM A269 standards, we replace it free of charge.

For stock sizes (1/2" to 2" side), we ship within 48 hours. Custom production orders ship within 7-10 business days. Free 300mm samples available — let your clients test quality before committing to a bulk order.

⚠️ Reference Data Only: Values shown are typical industry standards and may vary by manufacturer, lot, and heat treatment. For critical applications, please contact us to verify specifications or request a Mill Test Report (MTR).

Mechanical Properties

Chemical Composition (Typical)

Applicable Standards

ASTM A269: Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service

ASTM A554: Standard Specification for Welded Stainless Steel Mechanical Tubing

Available Square Tube Dimensions

Browse our 304 stainless steel square tube size chart below. Common dimensions include 1/2" square tubing, 1" square tube, and 2" square tube — all available in multiple wall thicknesses for structural and decorative use.

Standard Length: 20 ft (240"). Custom lengths available. Sizes above 2" available upon request.

Available Finishes

Choosing the right grade depends on your application environment, welding requirements, and budget. Here's a direct comparison:

Which one should you choose?

Choose 304 for most general square tube applications — frames, supports, railings. Best balance of performance and cost.

Choose 304L for extensive welding on thick sections where carbide precipitation is a concern.

Choose 316 for coastal or chemical environments where chlorides cause pitting.

Architectural:

Handrails, guardrails, and decorative trim - Excellent corrosion resistance and available polished finish.

Food & Beverage:

Equipment frames, support structures, and conveyor systems - Resists corrosion from food acids and cleaning solutions.

Structural Framing:

Lightweight frames for carts, workbenches, and enclosures - Good strength-to-weight ratio and easy fabrication.

Marine:

Non-critical components like grab rails and trim (for freshwater) - Good general corrosion resistance.

Automotive:

Custom framework and support brackets - Resists moderate temperatures and corrosive environments.

Medical:

Framework for medical stands and non-critical equipment - Easily sanitized and non-reactive.

Signage:

Posts and frames for indoor and outdoor signs - Withstands weather exposure and provides a clean look.

Machining

304 stainless is tougher than carbon steel and tends to work-harden. Use sharp tooling, rigid setups, and slow speeds with heavy, constant feeds to prevent glazing. The use of chip breakers and a suitable coolant is recommended.

Welding

Excellent weldability with all common fusion and resistance methods, both with and without filler metals. For heavier sections, post-weld annealing may be required to restore maximum corrosion resistance by redissolving chromium carbides. Use AWS E/ER 308 filler rods.

Finishing

Can be mechanically polished to various finishes, including a #4 satin (180 grit) or a #8 mirror finish. It can also be passivated to enhance its natural corrosion resistance by removing free iron from the surface after fabrication.

Bending & Forming

304 square tubes can be bent using standard tube benders. Due to the square cross-section, internal mandrel support is recommended to prevent wall collapse and corner distortion. Minimum bend radius is typically 3x the side dimension. For tight-radius bends, use a mandrel bender to maintain the square profile. For structural applications, consider the reduced wall thickness on the outer radius after bending.

Q: What is the difference between 304 and 316 stainless steel square tube?

A: 316 stainless steel contains molybdenum, which significantly enhances its resistance to chlorides and pitting corrosion, making it a better choice for marine or coastal environments. 304 is more cost-effective and suitable for most other applications.

Q: Is 304 stainless steel magnetic?

A: In its annealed, as-supplied condition, 304 stainless is austenitic and therefore non-magnetic. However, it can become slightly magnetic after cold working, such as bending or forming, due to the formation of martensite in the steel's crystal structure.

Q: Can I use 304 square tubing for a boat railing?

A: While 304 has good corrosion resistance, for saltwater marine environments, 316 stainless steel is strongly recommended. 304 is acceptable for freshwater boating applications or areas with minimal exposure to salt spray, but 316 provides superior long-term protection against pitting corrosion.

Q: What is the minimum order quantity (MOQ) for square tubes?

A: For stock sizes, MOQ is typically 100 ft per size. For custom sizes or large-volume orders, MOQ varies. Contact us for a quote specific to your needs.

Q: Can you cut square tubes to custom lengths?

A: Yes. Standard length is 20 ft (240"). We can cut to any custom length you specify. Tolerance on custom cuts is typically ±1/8". Contact us with your exact requirements.

Q: Do you provide Material Test Reports (MTR)?

A: Yes. Every order of 304 square tubes comes with a Mill Test Report certifying chemical composition and mechanical properties per ASTM A269. Third-party inspection (SGS, TUV) is also available upon request.

Q: What is the difference between seamless and welded 304 square tube?

A: Seamless tube is manufactured from a solid billet with no welded joint — uniform wall thickness, higher strength. Welded tube is made from strip rolled and longitudinally welded — more economical, suitable for most architectural and structural applications. Both are available per ASTM A269.

Q: How long does shipping take?

A: For stock sizes, we ship within 48 hours. For production orders (5000+ ft or custom specs), typical lead time is 7-10 business days. We ship to over 100 countries worldwide.

Q: Can I get a sample before ordering?

A: Yes. We provide free 300mm (approx. 12") samples so you can evaluate quality, finish, and dimensions before committing to a larger order. Just cover the shipping cost.

Q: Can 304 stainless steel square tube be used outdoors?

A: Yes, 304 is suitable for most outdoor environments (non-coastal). It offers good resistance to atmospheric corrosion and weather exposure. For coastal or high-chloride environments, 316 grade is recommended for longer service life.

Q: What is the weight of 1 inch 304 stainless steel square tube per foot?

A: 1" x 1" 304 square tube with 0.065" wall weighs approximately 0.82 lb/ft. For 0.095" wall the weight is 1.17 lb/ft, and for 0.120" wall it is 1.43 lb/ft. See our dimension table above for full weight specifications by size and wall thickness.

Q: Where can I buy 304 stainless steel square tube directly from a China manufacturer?

A: Henan Shuangzhong manufactures 304 square tubes per ASTM A269 standards, ships to over 100 countries worldwide, and offers factory-direct pricing with full traceability. Free 300mm samples are available — contact us for a quote or to request a Mill Test Report.