304 Stainless Steel Welded Pipe
304 welded stainless steel pipe or tube is quoted as longitudinally welded product by ASTM A312, A249 or A554, grade, NPS and schedule or OD × wall. Common inquiry range: 6–406 mm round, 6 m or cut-to-length. Seamless is quoted as a separate route.
Supply routes
- In-house production or processing
- Qualified partner-mill sourcing
- Stock coordination
Grade datasheets:304
Where this product solves the job
- Process piping when the governing specification permits welded ASTM A312 material and the piping class defines the required schedule and tests.
- Heat-transfer or equipment tubing when the drawing and applicable tube standard define OD, wall, weld treatment and inspection.
- Architectural or structural tube when the order prioritizes geometry and finish under the appropriate non-pressure product standard.
When we recommend another route
- Project specifications or design codes that explicitly require seamless construction.
- Hygienic product-contact systems ordered without a sanitary tube standard, internal finish, weld treatment and cleaning criteria.
- An RFQ that mixes pressure pipe, exchanger tube and decorative tube requirements under one unspecified 304 welded tube description.
Standards we quote against
Send the product standard, edition and any dimensional or finish standard with the RFQ. We quote the ordered combination, not a generic grade name.
Ordered product standards: ASTM A312/A312M
What to send so we can quote the right route
- Start with the governing product standard and edition, grade and whether the item is pressure pipe, exchanger tube or mechanical tube.
- Define NPS and schedule or actual OD and wall thickness, dimensional tolerances, length, straightness and section shape.
- State the manufacturing and heat-treatment condition, permitted weld treatment and required NDE or pressure test from the purchase specification.
- Identify internal and external finish, critical face, weld-bead condition, roughness or reference sample where relevant.
- Specify plain or beveled ends, cut-length tolerance, marking, ordered documents, traceability and package protection.
Specifications
| Grade | 304 / 304L |
|---|---|
| Standard | ASTM A312 (industrial), A249 (heat exchanger), A554 (decorative) |
| Outer diameter | Common inquiry range: 6–406 mm round; squares 10×10–150×150 mm. |
| Wall thickness | Common inquiry range: 0.4–6.0 mm. |
| Length | Common inquiry range: 6 m standard, cut to length available. |
| Finish | Mill, polished 180/320/400/600 grit, hairline |
| End condition | Plain, capped for polished tube |
| Commercial basis | Quantity, MOQ, production route and delivery schedule are quoted for the ordered specification. |
Dimensions and Tolerances
| Thickness | Common inquiry range: 0.4–6.0 mm. |
|---|---|
| Length | Common inquiry range: 6 m standard, cut to length available. |
| Outer Diameter | Common inquiry range: 6–406 mm round; squares 10×10–150×150 mm. |
| Wall Thickness | Common inquiry range: 0.4–6.0 mm. |
| Order basis | Governing product and dimensional standard, delivery condition and any drawing-specific limits. |
| Special tolerances | Send special tolerances in the RFQ; we quote the accepted production route. |
Published ranges are technical references, not a live-stock or production-capability promise. We confirm the ordered size range, MOQ and delivery schedule in the quotation.
Edge or end condition
- Plain, capped for polished tube; final condition as ordered.
Testing and inspection
- Tests required by the purchased product standard.
- PMI, NDE, corrosion, roughness or other supplementary inspection quoted when the RFQ names method, lot scope and acceptance.
Order documents
- Heat identity with EN 10204 3.1, or the inspection document named in the RFQ, against mill, stock or partner-mill route.
- Supplementary reports linked to the ordered test plan.
Export packaging
- Pipe or tube ends capped, bundles strapped and covered for sea freight.
- Thin-wall or prepared ends cased when the ordered finish needs it; packing method stated in the quotation.
Quote the standard with the pipe
The same “304 pipe” phrase can describe products bought under different standards. A554 addresses mechanical tubing where geometry and appearance often drive the order. A312 covers austenitic stainless pipe for the specified service, while exchanger tubing follows its applicable tube standard. Send the exact product standard with the RFQ; we quote that route.
Quote the polish
Send the starting surface, critical side, abrasive route or reference sample, roughness where relevant, grain direction and acceptable weld visibility. We quote sleeves and other protection with the finish, tube geometry and packing route.
Related datasheets
See the 304 grade page for chemistry and equivalents; estimate order weight with the weight calculator.
Common ordering mistakes
- Using ASTM A312, A249 and A554 as interchangeable labels even though they serve different product and acceptance contexts.
- Ordering by outside diameter alone and omitting schedule or wall thickness, which prevents a complete dimensional definition.
- Requesting polished pipe without naming the critical surface, weld condition, roughness or reference appearance.
- Assuming welded construction can replace seamless where the project specification or client approval fixes the manufacturing route.
Handling and transport risks
- Thin-wall tube can ovalize or dent when bundle supports, straps and fork positions are not matched to section and length.
- Prepared bevels and cut ends can be damaged or contaminated if end protection is not defined for the transport route.
- Polished surfaces can suffer sleeve rub, strap marks or carbon-steel contamination during bundling and site handling.
- Water retained inside capped lengths can stain internal surfaces if drying and closure timing are not controlled.
Technical content updated: 2026-07-31
Published by Tsingshan (Shandong) Iron & Steel Co., Ltd..Sources, update policy and technical limitations.
Typical Applications
Related technical resources
Grades
Published standards
Applicable standards
ASTM A312/A312M
What to Include in Your RFQ
Send the known values first. We use them to quote the ordered option, inspection plan and delivery route.
- Grade and governing standard
- 304; ASTM A312/A312M. State the exact ordered combination.
- Dimensions and tolerances
- Provide thickness, length, outer diameter, wall thickness and identify which order basis, special tolerances requirements govern acceptance.
- Finish, processing and edge or end condition
- Hairline; Stainless Steel Cut-to-Length and Leveling, Stainless Steel Polishing and Surface Finishing; Plain, capped for polished tube; final condition as ordered..
- Inspection, documents and packing
- Testing: Tests required by the purchased product standard.; PMI, NDE, corrosion, roughness or other supplementary inspection quoted when the RFQ names method, lot scope and acceptance. Documents: Heat identity with EN 10204 3.1, or the inspection document named in the RFQ, against mill, stock or partner-mill route.; Supplementary reports linked to the ordered test plan. Packing: Pipe or tube ends capped, bundles strapped and covered for sea freight.; Thin-wall or prepared ends cased when the ordered finish needs it; packing method stated in the quotation.
- Quantity, destination and requested delivery window
- Send quantity per size, unit, destination city or port, trade term and requested delivery window so we can quote the supply and freight route.
Product RFQ Example
RFQ example: ASTM A312/A312M TP304L welded pipe, NPS 2 Schedule 10S, solution-treated condition required by the ordered specification, 6 m random lengths, plain ends, dimensional and test requirements to the named edition, ordered inspection document with heat traceability, end protection and export bundles for delivery to the named port; quote welded availability and delivery separately.
Frequently Asked Questions
Is ASTM A554 decorative tube suitable for an ASTM A312 pressure-pipe order?
Not by description alone. The products have different intended use and acceptance requirements. Pressure service should be purchased to the product specification and piping design requirements named by the project.
Should a welded tube RFQ use NPS and schedule or OD and wall?
Use the dimensional system required by the governing standard and drawing. Process pipe is commonly defined by NPS and schedule, while equipment or mechanical tube is often ordered by actual OD and wall thickness.
Which weld details matter on a polished 304 tube?
State internal and external weld-bead condition, heat treatment, critical surface, required roughness or appearance sample, grain direction and whether the seam location affects fabrication or viewing.
Can welded 304 pipe be quoted against a seamless requirement?
It can be offered only as a clearly identified alternative for project review. It must not be treated as compliant when the governing specification, design code or client document requires seamless construction.
How should cut lengths and ends be specified?
Give finished length and tolerance, squareness, burr removal, plain or beveled end geometry, cap or protector requirement, marking location and any fit-up criteria from the fabrication drawing.
Quote request
Get a Stainless Steel Quote
Send the product, grade and quantity you already have. We will complete the specification and quote the supply route.