ASTM A269 / A269M (ASME SA-269): Seamless & Welded Austenitic Stainless Steel Tubing for General Service
ASTM A269 / A269M is the standard specification governing seamless and welded austenitic stainless steel tubing for general service. It spells out the grades, chemical composition, mechanical properties, dimensions and tolerances, and testing that stainless tube (specified by outside diameter × wall thickness) has to meet for fluid and gas transport, chemical processing, and instrumentation lines. ASTM International's Committee A01 on Steel publishes the standard, and it's been adopted into the ASME Boiler & Pressure Vessel Code as ASME SA-269.
ASTM A269 covers material and dimensions only. It isn't a pressure-class rating, and it stands apart from ASTM A213 (boiler and heat-exchanger tube), ASTM A312 (stainless pipe, sized by NPS), and A270 (sanitary tube). Crestflo supplies A269-conforming stainless instrumentation tubing in the austenitic grades. Every shipment comes with a material test certificate and heat-number traceability.
Also Known As: ASTM A269/A269M, ASME SA-269, SA269 & A269 TP316L
Specifiers, buyers, and mills reference this standard under several designations. It's written as ASTM A269/A269M (the imperial and metric companion together) and shortened to A269, A-269, or A269M (the metric-unit version). In full, the designation stands for the Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service, that's the A269 full form and meaning. In ASME code work it shows up as ASME SA-269, SA-269, SA269, or SA 269, the ASME equivalent adopted into the Boiler & Pressure Vessel Code. Grade-qualified call-outs such as A269 TP316, A269 TP316L, A269 316L, A269 TP304, A269 TP304L, and SA269 TP316 each point to a distinct austenitic grade defined inside this one specification.
Scope, Designation & Current Revision
ASTM A269 covers stainless steel tubing for general corrosion-resisting and low- or high-temperature service. Think of the everyday process, sample, impulse, and instrument lines, the ones that don't fall under a boiler, heat-exchanger, or sanitary specification. It's a dual-unit standard. A269 carries inch-pound values, while A269M carries SI (metric) values, and the two are treated as separate but parallel documents. ASTM revises the specification periodically; editions such as A269-13, A269-15a, A269-22, and A269-24 have all been issued. Buyers should cite whatever edition their project or purchase order calls out, not assume there's a single "current" or "latest" version. The authoritative standard isn't a free download. ASTM sells the licensed PDF, the A269-24 PDF, for instance, through its store, and this page presents the grade, chemistry, and test data in HTML so it can be read and cited directly without reproducing the copyrighted text. Values below are stated per ASTM A269/A269M and can be adjusted to requirement.
What ASTM A269 Covers: Seamless and Welded Tube Forms
A269 permits tube produced in two forms: seamless, meaning no weld seam, and welded, which is formed and seam-welded from strip. Both come in the solution-annealed condition. That keeps the austenitic tube soft and ductile, so it can be bent and so a ferrule can seat and grip properly during compression-fitting make-up. If your specification calls for one form specifically, order to it explicitly. Both are acceptable under A269. Crestflo supplies A269 tube as seamless tubing, welded tubing, instrumentation tubing, hydraulic tubing, and coiled tubing.
ASTM A269 Grades: TP304/304L, TP316/316L & UNS Numbers
A269 covers austenitic stainless grades only, nothing else. Instrumentation work leans hardest on 304/304L and 316/316L. The standard's grade table lists other austenitic grades too, among them TP321, TP347, TP317, TP309, and TP310, meant for higher-temperature or specialized service.
| Grade | UNS | Notes | Material reference |
|---|---|---|---|
| TP304 | S30400 | General corrosion-resisting service | 304 / 304L |
| TP304L | S30403 | Low-carbon, improved weldability | 304 / 304L |
| TP316 | S31600 | Molybdenum-bearing, chloride resistance | 316 / 316L |
| TP316L | S31603 | Low-carbon, the default instrumentation grade | 316 / 316L |
| TP321 / TP347 / TP317 / TP309 / TP310 | Various | Other austenitic grades in the A269 grade table | instrumentation-grade alloys |
Higher-alloy tube, 904L, duplex 2205 / super duplex 2507, and nickel alloys, isn't covered by A269. Duplex tube falls under ASTM A789, and each alloy carries its own specification. Trying to pick between the two most common grades? See 316 vs 316L.
ASTM A269 Chemical Composition (TP304, TP304L, TP316, TP316L)
Representative composition limits (weight %, maximum unless a range is shown) for the core austenitic grades, per the ASTM A269/A269M grade table:
| Element | TP304 | TP304L | TP316 | TP316L |
|---|---|---|---|---|
| Carbon (C) | 0.08 | 0.035 | 0.08 | 0.035 |
| Manganese (Mn) | 2.00 | 2.00 | 2.00 | 2.00 |
| Phosphorus (P) | 0.045 | 0.045 | 0.045 | 0.045 |
| Sulfur (S) | 0.030 | 0.030 | 0.030 | 0.030 |
| Silicon (Si) | 1.00 | 1.00 | 1.00 | 1.00 |
| Chromium (Cr) | 18.0–20.0 | 18.0–20.0 | 16.0–18.0 | 16.0–18.0 |
| Nickel (Ni) | 8.0–11.0 | 8.0–13.0 | 11.0–14.0 | 10.0–15.0 |
| Molybdenum (Mo) | — | — | 2.0–3.0 | 2.0–3.0 |
Values per applicable standard; customizable to requirement.
ASTM A269 Mechanical Properties & Hardness
Minimum mechanical properties for the annealed austenitic grades, per ASTM A269/A269M:
| Property | 304 / 304L | 316 / 316L |
|---|---|---|
| Tensile strength, min | 75 ksi [515 MPa] (L: 70 ksi [485 MPa]) | 75 ksi [515 MPa] (L: 70 ksi [485 MPa]) |
| Yield strength, min | 30 ksi [205 MPa] (L: 25 ksi [170 MPa]) | 30 ksi [205 MPa] (L: 25 ksi [170 MPa]) |
| Elongation, min | 35% | 35% |
| Hardness, max | 90 HRB | 90 HRB |
Hardness tops out at 90 HRB on the Rockwell B scale. The tube gets its low hardness and high ductility from the solution-annealed heat-treatment condition, which is what makes tube bending possible and lets the ferrule seat correctly in a compression fitting. Values follow the applicable standard, though they can be adjusted to requirement.
ASTM A269 Dimensions, Wall Thickness & Tolerances
A269 tube is specified by outside diameter × wall thickness, not by NPS/schedule. Common instrument sizes run from 1/4 in. to 1 in. OD with typical walls of 0.028, 0.035, 0.049, and 0.065 in.; the standard also covers smaller and larger sizes for general service. Wall can be ordered as minimum wall or average wall, and A269 sets permissible variations (OD tolerance and wall-thickness tolerance) on OD, wall thickness, length, and straightness in its dimensional tables. Because A269 and A269M are separate unit systems, an order specifies whichever governs, inch-pound values under A269, SI values under A269M. See the tubing size chart for reference dimensions and tube sizing & wall thickness for selection guidance.
ASTM A269 Testing, Marking & Traceability
A269 lays out a test regime a conforming heat and tube has to pass:
| Test | Applies to | Purpose |
|---|---|---|
| Chemical analysis | Every heat | Confirm grade composition |
| Tension | Every grade | Verify tensile, yield, elongation |
| Hardness | Every grade | Confirm the hardness limit |
| Flattening / flaring | As applicable to form | Verify ductility and soundness |
| Hydrostatic or nondestructive electric (eddy-current) | Every tube | Detect leaks and defects |
The standard also requires marking (stenciled onto each length) with the specification, grade, size, and heat identification. Crestflo furnishes A269 tube with a material test certificate to EN 10204 3.1 (3.2 on request) and a heat/lot number on every length, plus PMI and in-house NDT, see heat-number traceability & MTC, EN 10204 3.1 / 3.2 certificates, and testing & inspection.
Does ASTM A269 Give a Pressure Rating? The Honest Answer
No. ASTM A269 assigns no pressure class. It's a material and dimensional specification only, nothing more. Allowable working pressure gets calculated from the tube's OD, wall thickness, and the allowable stress of the grade under the governing design code, for process piping, that's ASME B31.3. A269 gives you a qualified, traceable tube. The design code and your service conditions determine the pressure it can actually carry. Work an allowable pressure with the tube pressure & wall-thickness calculator, and check pressure, temperature derating for elevated-temperature service.
ASTM A269 vs A213, A312, A270 & A789
A269 gets mixed up with neighboring tube and pipe standards all the time. The differences boil down to product form, service focus, and grade family.
| Standard | Product form | Service focus | vs A269 | Reference |
|---|---|---|---|---|
| A269 | Tube (OD × wall), seamless + welded | General service, instrumentation | — | This page |
| A213 | Seamless tube | Boiler, superheater, heat-exchanger (high temperature) | Higher-temperature seamless tube; often dual-certified with A269 | ASTM A213 |
| A312 | Pipe (NPS / schedule) | Corrosive and high-temperature piping | Pipe, not tube; sized by NPS | ASTM A312 |
| A270 | Tube | Sanitary (dairy / pharmaceutical) | Hygienic ID finish; not general service | Adjacent standard |
| A249 | Welded tube | Boiler / heat-exchanger | Welded, heat-treated boiler tube | Adjacent standard |
| A789 | Tube | Duplex stainless service | Duplex, not austenitic | ASTM A789 |
ASTM A269 Tube in Instrumentation Systems
Annealed 316/316L A269 tube is the standard choice for impulse, instrument, analyzer, sample, and hydraulic lines. It brings chloride resistance together with the soft, ductile temper a compression fitting actually needs. Seal integrity in a tube fitting comes down to whether the tube meets A269's hardness, wall, and ovality limits. Get any of those out of spec and the ferrule won't seat or grip the way it should. As for A269 versus A213 in instrumentation work, A269 covers everyday general-service and instrumentation applications, while A213 governs elevated-temperature boiler and heat-exchanger tube. Instrument tube often carries dual certification to both standards. Specifying A269 tube alongside your fittings remains the simplest way to keep the tube-to-fitting connection working as it was designed to.
ASTM A269 Tube from Crestflo: Products & Request
As a US-serving ASTM A269 stainless steel tube supplier and manufacturer, Crestflo makes A269-conforming 304/304L and 316/316L stainless tubing, instrumentation tubing, seamless tubing, welded tubing, hydraulic tubing, and coiled tubing, in imperial and metric sizes alike. Standard items ship from ready stock; specials are made to order, with delivery running 6–8 weeks. Origin is Indian. US or European melt can be arranged on request, and full material traceability comes with it.
- Request a quote for A269 tube
- Request a sample
- Browse stainless steel & alloy tubing
Why Crestflo for A269-Conforming Tube
Crestflo is the instrumentation division of a four-decade-old, Government-of-India-recognized export house with a Middle-East delivery track record, and is ISO 9001 / 14001 / 45001 & PED certified. Every A269 tube carries a heat/lot number and ships with an EN 10204 3.1 material test certificate (3.2 on request), backed by PMI and in-house NDT. Certifications are stated, not published by number, on content pages; the underlying certificates live in the quality area. Origin is handled honestly, Indian origin, with US / European melt on request where domestic-melt or TAA sourcing is required (see US-origin compliance). We manufacture to the applicable standard and customize to your requirement, with small MOQ and private label available. We Engineer Confidence.
Frequently Asked Questions
What is ASTM A269 material?
ASTM A269 isn't one single material. It's a specification, covering seamless and welded austenitic stainless steel tubing in grades TP304, TP304L, TP316, TP316L and others, meant for general service. The grade you actually order, most often 316/316L, is what determines the real chemistry and properties.
What is the difference between ASTM A269 and A312?
A269 covers stainless tube, specified by OD × wall, for general and instrumentation service. ASTM A312 covers stainless pipe, sized by NPS and schedule, for piping systems. They are different product forms with different sizing conventions.
What is the difference between ASTM A269 and A213?
Both cover stainless tube, but ASTM A213 targets seamless boiler, superheater, and heat-exchanger tube for elevated-temperature service, while A269 covers general-service and instrumentation tube in seamless or welded form. Tube is frequently dual-certified to A213 and A269.
How does ASTM A270 differ from A269?
A270 covers sanitary tube (dairy and pharmaceutical work) and calls for hygienic inside-diameter finishes. A269, by contrast, is for general-service and instrumentation tubing, and it doesn't carry those sanitary finish requirements.
Does ASTM A269 specify a pressure rating?
No. A269 covers material and dimensions, nothing more. Working pressure gets calculated separately, pulling from the tube's OD, its wall thickness, and the allowable stress set by whatever design code governs the job, ASME B31.3 among them.
Which grades does ASTM A269 cover, and which suit instrumentation?
Austenitic stainless grades include TP304, TP304L, TP316, and TP316L, along with TP321, TP347, TP317, TP309, and TP310. For instrumentation work, 316/316L is the go-to choice, thanks to its resistance to chlorides.
Is ASTM A269 tube seamless or welded?
Both forms are permitted, so specify whichever your project calls for. Crestflo supplies A269 tube as seamless or welded.
Can I get 904L, duplex, or Inconel tube "to A269"?
Not exactly. A269 covers austenitic stainless. 904L, duplex 2205 and 2507, and the nickel alloys sit under different specs entirely, duplex tube, for instance, falls under ASTM A789. Give us the alloy and we'll tell you which standard applies.
Do you supply A269 tube with a material test certificate?
Crestflo provides an EN 10204 3.1 material test certificate on every length, with a 3.2 version available on request. Each one carries a heat/lot number. PMI and in-house NDT come standard.
Is ASME SA-269 the same as ASTM A269?
Effectively, yes. SA-269 is ASME's Boiler & Pressure Vessel Code adoption of ASTM A269. The two documents are technically identical, and SA-269 is what gets used for ASME code work.
What sizes and tolerances does ASTM A269 cover?
Tube gets specified by OD × wall, common instrument sizes run 1/4 in. to 1 in. OD, with walls of roughly 0.028 to 0.065 in. Permissible variations on OD, wall, length, and straightness show up in the standard's tables.
Related Standards & Pages
- ASTM A213, seamless boiler & heat-exchanger tube
- ASTM A312, austenitic stainless pipe
- ASTM A789, seamless & welded duplex tube
- ASME B31.3, process-piping design pressure
- EN 10204, 3.1 / 3.2 material test certificates
- NACE MR0175, sour-service materials
- All instrumentation tube & fitting standards
- 316 / 316L tube grade, TP316 / TP316L
- 304 / 304L tube grade, TP304 / TP304L
- 316 vs 316L, grade selection