TP309 Seamless Stainless Steel Tube
At a glance — TP309 Tube
| Specification | ASTM A213 — the edition cited on the PO governs |
| Ordering basis | OD × wall × length, wall basis stated (minimum or average) |
| Sourcing range | OD 6 – 257 mm · wall 0.5 – 35 mm · length ≤ 18 m; each standard × OD × wall × length × condition confirmed in writing |
| Condition | Solution annealed; pickled & passivated, bright annealed or polished |
| Documents | EN 10204 3.1 MTC as standard (3.2 on request); hydrostatic or NDT electric test on every length |
Sourcing capability, not a stock list — availability, MOQ and lead time are stated in the written quotation.
Grade note — TP309 (UNS S30900) has been withdrawn from the current editions of ASTM A213 and A312 and can no longer be ordered as a TP grade. The data on this page are for TP309S (UNS S30908), the low-carbon grade currently produced for this duty. For creep-limited service, the high-carbon variant is TP309H (UNS S30909).
Sizes, Wall Basis and Ordering
Two figures are kept apart here: the overall sourcing range — what we can supply ex-stock or source mill-direct — and the confirmed combination for your order (standard × OD × wall × length × manufacturing condition). The tables state the first; the written quotation fixes the second.
Supply combinations by outside diameter
| OD band, mm | Wall range, mm | Supply route (ex-stock / mill-direct) | Order status |
|---|---|---|---|
| ≤ 25 | 0.5 – 3.0 | Cold-drawn / cold-pilgered | In stock · 3–7 days / mill-direct · 25–35 days |
| > 25 – 60 | 0.8 – 6.0 | Cold-drawn | In stock · 3–7 days / mill-direct · 25–35 days |
| > 60 – 114.3 | 1.5 – 10.0 | Cold-drawn; hot-finished above 8 mm wall | In stock · 3–7 days / mill-direct · 25–35 days |
| > 114.3 – 219.1 | 2.5 – 20.0 | Hot-finished; cold-finished on request | In stock · 3–7 days / mill-direct · 25–35 days |
| > 219.1 – 257 | 4.0 – 35.0 | Hot-finished (extruded) | In stock · 3–7 days / mill-direct · 25–35 days |
Stock items are marked In stock; everything else is mill-direct with a stated lead time. Wall figures give the range that can be drawn or rolled for that OD band; the ordered wall is always stated with its basis. Above 225 mm OD the tabulated dimensional bands no longer apply and the basis is agreed in writing before the order is accepted.
Ordering options
| Item | What can be ordered |
|---|---|
| Outside diameter | 6 – 257 mm — drawn to the ordered OD, not to NPS |
| Wall thickness | 0.5 – 35 mm — minimum or average basis, stated on the order |
| Length | Random 5–7 m, fixed up to 18 m, or cut to length |
| Ends | Plain, bevelled, or capped for export packing |
| Surface | Pickled and passivated, bright annealed, or polished |
| Delivery condition | Solution annealed; hardness and grain size reported on request |
Sizes at the edge of a band, and anything above 225 mm OD, are quoted after technical review. If your enquiry is written in NPS and schedule, the quotation will restate it as OD × wall so both sides work from the same numbers.
Ordering Standards: A213 vs A269
Both specifications can describe the same tube, but they do not ask for the same evidence. A213 is the primary specification for this page: each tube carries an integrity test and the wall is ordered on a stated basis. A269 is the adjacent specification, and whether it applies depends on the test regime and the design code. Which one applies is a purchasing decision — state it on the enquiry.
| Item | ASTM A213 | ASTM A269 |
|---|---|---|
| Scope | Tube for heat exchangers, condensers, boilers and superheaters | General-purpose tube and pressure tubing; scope depends on the edition |
| Ordering basis | OD × wall × length, wall basis stated | OD × wall × length; average or minimum wall as agreed |
| Wall basis | Minimum wall unless the order states average | Average wall unless minimum is specified |
| Testing | Integrity test on every length, plus flattening, flare or bend as specified | Integrity test and product analysis; tension per lot |
| Typical use | Heat transfer and pressure parts | Instrumentation, process lines and general corrosion service |
Duplex and super duplex tube is ordered to A789, which carries the same testing logic as A213 but its own chemistry and mechanical tables. Nickel alloys follow the B-series: state the specification and edition, because mechanical values differ between B622, B163, B407, B444 and B167.
Chemical Composition (TP309S Heat-Analysis Limits)
Chemical composition, % by weight:
| Cr | Ni | Mn | Si | P | S | Fe | C |
|---|---|---|---|---|---|---|---|
| 22.00–24.00 | 12.00–15.00 | ≤ 2.00 | ≤ 0.75 | ≤ 0.045 | ≤ 0.030 | Bal | ≤ 0.08 |
Values are the heat-analysis limits of the specification named above. Product analysis on the finished tube or pipe may differ within the tolerances the standard permits, and the actual heat analysis is printed on the mill test certificate.
Mechanical Properties and Physical Data
Mechanical properties:
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 515 MPa | ≥ 205 MPa | ≥ 35% | ≤ 192 HBW |
Typical physical properties:
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 7.9 g/cm³ | 1400–1450 °C approx. | 16.5 µm/m·°C (20–100°C) | 14.2 W/m·K (20°C) | 200 GPa | 0.78 x 10⁻⁶ Ω·m (20°C) |
Tensile and yield values are specification minima at room temperature; hardness and grain size are reported when the purchase order asks for them. Design values at service temperature must be taken from the applicable code, not from this table.
Permissible Variations in Dimensions (A213)
Dimensional acceptance follows the tables of the primary specification — A1016/A1016M for A213 and A789 tube. The bands below are the ones buyers ask about most; the edition cited on the purchase order governs, and measured values are recorded on the mill test certificate.
Outside diameter
| Outside diameter, mm | Permissible variation |
|---|---|
| ≤ 25 | ± 0.10 mm |
| > 25 – 40 | ± 0.15 mm |
| > 40 – 50 | ± 0.20 mm |
| > 50 – 100 | ± 0.38 mm |
| > 100 – 200 | ± 0.76 mm |
| > 200 – 225 | ± 1.14 mm |
| > 225 – 257 | Not tabulated — agreed in writing |
Variations apply to the individual measurement, not to the average of the length. For U-bent tube the bend radius and leg length tolerances are agreed separately.
Wall thickness
| Condition | Permissible variation |
|---|---|
| Cold-finished, minimum-wall basis | ± 10 % of ordered wall, no point below the minimum |
| Cold-finished, average-wall basis | ± 10 % of ordered wall on the average of the length |
| Hot-finished | + 22.5 % / − 0 % of ordered wall |
The basis must match the design calculation. A tube ordered on minimum wall and a tube ordered on average wall are not interchangeable, even at the same nominal size.
Fixed lengths: + 3 mm / − 0 mm. Random lengths 5–7 m unless a fixed length is ordered; straightness 1 in 600, and end squareness is inspected before packing.
Inspection, Testing and Mill Test Certificates
Three groups of evidence are separated here, because only the first is inside the base price. Anything in the second and third groups has to be written on the purchase order — it cannot be added after the mill test certificate has been issued.
| Group | Content | How it is triggered |
|---|---|---|
| 1 — Included | Chemical analysis, tensile test, flattening or bend test, hydrostatic or nondestructive electric test, dimensional check, EN 10204 3.1 certificate | Standard supply; no extra instruction needed |
| 2 — Written on the PO | Ultrasonic or eddy-current testing to a stated acceptance level, PMI on each heat, intergranular corrosion test, grain size, hardness survey, 3.2 certificate | Must appear on the purchase order; priced per order |
| 3 — Third party | TPI witness (SGS, BV, TÜV, Lloyd's), destructive sampling, third-party laboratory, packing inspection, pre-shipment photographs | Arranged per order; extends the lead time |
The test route is not interchangeable after the fact: if the certificate has to show ultrasonic testing, say so on the enquiry, because a hydrostatic-only pipe cannot be re-certified as ultrasonically tested.
What the mill test certificate records
| Heat number | The melt the item came from, traceable to the raw-material certificate |
| Grade and specification | Grade designation plus the standard and edition the order cites |
| Chemical analysis | Actual values for each element, not the range |
| Mechanical results | Tensile, yield, elongation and hardness as tested |
| Test route | Hydrostatic or nondestructive electric test, plus any agreed NDT with the method reference |
| Heat treatment | Solution-annealing temperature range and cooling method |
| Dimensions | Ordered OD, wall and length, with the measured values on request |
TP309 Tube Applications and Points to Confirm
Each application below names the duty the grade is normally chosen for, and what should be settled before the order is placed — the third column decides whether this grade is the right one:
| Industry | Typical duty |
|---|---|
| Industrial furnaces | furnace and kiln duty |
| Power generation | boiler, superheater and feedwater duty |
| Petrochemical & refining | hydrocarbon and sour-service duty |
| Chemical processing | aggressive reaction and transfer duty |
| Cement & lime | dusty, alkaline kiln duty |
| Automotive | exhaust and thermal-cycle duty |
Points to confirm before ordering
- Medium, concentration and chloride content — the figures that decide whether this grade holds
- Design temperature and pressure, including upset and cleaning cycles
- Whether the joint is welded, and the post-weld condition required
- Inspection and document scope: NDT level, PMI, third-party witness
Send the medium, concentration, temperature, pressure and chloride level, and we will confirm the grade — or propose the next one up if the margin is narrow.
Grade Selection: TP309 vs TP310
| Property | TP309 | TP310 |
|---|---|---|
| PREN, typical | 22 | 25 |
| Molybdenum | — | — |
| Yield strength, min. | ≥ 205 MPa | ≥ 205 MPa |
| Service temperature | ≈ 1000 °C | ≈ 1100 °C |
| Choose when | General corrosion service, welded assemblies, cost-sensitive projects | Lower alloy content is enough for the duty |
PREN is indicative only and is calculated from the composition ranges above — it is not an acceptance value. Where the duty sits between two grades, the deciding factors are usually chloride content, temperature and whether the joint is welded.
Frequently Asked Questions
What sizes can be supplied in TP309 tube?
The overall sourcing range is OD 6 – 257 mm, wall 0.5 – 35 mm, length 18 m. The band table shows the wall range normally held or supplied for each OD band; the exact combination of standard, OD, wall, length and manufacturing condition is confirmed in the quotation. Sizes at the edge of a band are quoted after technical review.
Is this page a stock list?
In part. Stocked sizes are marked In stock and ship in 3–7 days; everything else is mill-direct with a 25–35 day lead time, confirmed per item in the quote.
Should the wall be ordered minimum or average?
Either, but it must be stated. A213-type tube is normally ordered on a minimum-wall basis, which is what the tolerance table in the dimensional section assumes. If your design code calls for average wall, say so on the enquiry and the quotation changes basis.
Which specification applies — A213 or A269?
ASTM A213 is the primary specification for this tube and the one the page describes. ASTM A269 is the adjacent specification; whether it applies depends on the ordered form, the test regime and the design code. State the standard and edition on the enquiry and the certificate will cite the same one.
Which tests and documents are included?
Mandatory: one integrity test per length (hydrostatic or nondestructive electric), tensile test per lot, dimensional check and an EN 10204 3.1 mill test certificate. Optional and only when written on the order: ultrasonic or eddy-current testing to a stated level, PMI, intergranular corrosion test, grain size, third-party witness and 3.2 certification.
How does TP309 compare with TP310?
TP310 is the usual comparison grade. TP309 carries PREN of about 22 against 25 for TP310, with a minimum yield of 205 MPa. The change is normally made when the duty — chloride level, temperature or pressure — leaves TP310 without margin over the design life.
Request a TP309 Tube Quotation
Send: specification and edition, OD or NPS, wall and wall basis, length, quantity, surface finish, inspection scope and documents, and destination port. The quotation will restate the confirmed size combination, delivery condition, documents included and lead time for TP309 Tube.
Related Product Forms and Grades
Other forms and neighbouring grades, each with its own specification — confirm the applicable standard on every order:
- TP309 seamless pipe — UNS S30908 · W-Nr 1.4833
- TP310 seamless tube — TP310 — the grade normally compared with TP309 on this duty
- Contact the sales team — Sizes outside the range, non-standard lengths and third-party inspection
Technical data compiled from the ASTM/ASME specification tables cited above and from published mill data. Page reviewed by the Xinzhe technical team, 09–11-2026. All values must be confirmed against the edition current at the time of order and against the heat certificate.
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