Stainless steel grades
Enquire for SS 321 pipe or tubing. Share your standard, dimensions and quantity, and confirm whether the order calls for 321 or 321H.
Request a quoteTechnical reference
| Field | Order reference |
|---|---|
| Standard | A312 TP321 pipe or the specified tube standard |
| Product or route | Titanium-stabilised austenitic stainless, UNS S32100 |
| Critical dimensions and fit | State the approved forming condition, critical OD tolerance and bend layout if required |
| Supply enquiry | Confirm sizes, lengths, route, documentation and lead time for your order |
Selected ASME B36.19 dimensions. Schedule columns give nominal wall thickness. Theoretical inside diameter and mass use nominal dimensions, with a reference density of 8,000 kg/m³. Actual mass varies by grade and tolerances.
| NPS | OD (mm) | 10S wall (mm) | 40S wall (mm) | 80S wall (mm) | 40S ID (mm) | 40S kg/m |
|---|---|---|---|---|---|---|
| 1 | 33.40 | 2.77 | 3.38 | 4.55 | 26.64 | 2.55 |
| 2 | 60.33 | 2.77 | 3.91 | 5.54 | 52.51 | 5.54 |
| 3 | 88.90 | 3.05 | 5.49 | 7.62 | 77.92 | 11.51 |
| 4 | 114.30 | 3.05 | 6.02 | 8.56 | 102.26 | 16.38 |
| 6 | 168.28 | 3.40 | 7.11 | 10.97 | 154.06 | 28.80 |
Reference ASME B36.19 dimensional standard · Tonkin stainless pipe dimensional chart
For tubing, order by actual outside diameter and wall. Drawing example: 25.4 × 2 mm straight tube or NPS 2 Sch 40S pipe.
Use the approved design code and service conditions. The applicable rating depends on material, temperature, minimum effective wall, joint details and the limits of the connected assembly. A schedule or a hydrostatic test result alone cannot establish an operating pressure.
Reference ASME process piping code B31.3
Selected chemistry by mass for the A312 pipe designations below. The ordered edition, full element limits and any applicable notes govern acceptance. A dash means the value is omitted here.
| Grade | UNS | C (%) | Cr (%) | Mo (%) | Grade feature |
|---|---|---|---|---|---|
| TP321 | S32100 | ≤0.08 | 17–19 | — | Titanium stabilised |
Reference ASTM A312/A312M scope · Centravis tubular product catalogue · Alleima high-temperature tubular grades
Selected minimum room-temperature tensile and yield strengths for A312 pipe. Elongation acceptance depends on the specimen orientation and applicable thickness basis. For tube orders, apply the nominated tube specification.
| Grade | Tensile minimum (MPa) | Yield minimum (MPa) |
|---|---|---|
| TP321 | 515 | 205 |
Reference ASTM A312/A312M scope · CTS A312 technical reference · Tioga A312 pipe grade reference
Check the titanium-stabilised grade and relevant heat treatment evidence.
| When | What to check |
|---|---|
| Before ordering | Document the required test method, edition and any witness points |
| At delivery | Match the material report and heat or lot identification to the shipment |
321H has its own material requirements for a hot-duty order.
For the enquiry, state the approved forming condition, critical OD tolerance and bend layout if required.
A312 TP321 pipe or the specified tube standard · 25.4 × 2 mm straight tube or NPS 2 Sch 40S pipe. Add quantity, lengths, delivery city and the required reports.
Ordering guidance
For a 321 requirement, state the grade exactly as specified and include the product standard. A similar grade name or dimensional match does not establish that a quoted item satisfies the same material requirement.
For a pipe spool, give the nominal size, schedule, length and end preparation. For a tube, give actual outside diameter, wall, length and finish. If the project requires tests beyond the nominated standard, include them on the purchase list.
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Buyer’s guide
321 (UNS S32100) is a titanium-stabilised austenitic stainless grade. It is specified for some welded or temperature-exposed assemblies. If the drawing calls for 321, carry that exact designation through the material enquiry. 321H is a separate grade with its own requirements under the applicable product standard.
For a welded spool, give nominal pipe size, schedule or wall, end preparation and the relevant specification. For tube forming, identify actual OD and wall, the delivery condition and any bending details the fabricator needs. If an outside diameter has to fit through an existing sleeve, state the tolerance on the purchase line instead of relying on a nominal size.
Check the offer for grade, standard, route, delivery condition and length. Where the project imposes material traceability or additional test records, attach the inspection schedule. Give any permitted alternatives their own line and have the project reviewer compare them to the approved design.
For a thermal-cycling assembly, send the drawing with the 321 material callout, tube length, outside diameter, wall and the bend layout. Identify whether the supplier is pricing straight stock or finished bent sections.
The radius is set by the drawing and forming requirements. Give it explicitly if ordering a finished component.
Technical references Alleima 321 grade data · Alleima high-temperature tube grades
Prepare your enquiry
| Item | What to send |
|---|---|
| Product details | 321 · product standard · NPS or OD · wall · finish · additional tests |
| Delivery | Quantity with units, delivery city and required date if known |
| Acceptance | Required certificates and inspection scope; attach the drawing revision where applicable |
UNS S32100 — A titanium-stabilised austenitic grade. Confirm 321 versus 321H on the purchase order.
Use the 321H page and call out the H grade in the enquiry so it is quoted and checked separately.
Technical reference: Grade designation reference
Related products and standards
Project enquiries
Send your dimensions, quantities and delivery city. Include any inspection or material certificate requirements so they can be quoted against the same line items.
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