What temperature can 309 stainless steel pipe withstand?

309 stainless steel resists oxidation up to approximately 1900 degrees Fahrenheit (1038 degrees Celsius) under non-cyclic conditions, and approximately 1850 degrees Fahrenheit (1010 degrees Celsius) under conditions involving frequent thermal cycling.

What forms of stainless steel 309 pipes and tubes are available?

Stainless steel 309 is available in seamless and welded (ERW and EFW) forms, in round, square, rectangular, and hollow-section shapes, in sizes from half-inch NB up to 24-inch NB for pipe and half-inch OD up to 12-inch OD for tubing.

What documentation is provided with 309 pipe and tube orders?

Orders are supplied with EN 10204 3.1 Mill Test Certificates, with IBR Form III-D available for boiler-code projects in India, along with Positive Material Identification (PMI) testing and third-party inspection on request.

Do you export stainless steel 309 pipes and tubes worldwide?

Yes, stainless steel 309 pipes and tubes are stocked in Mumbai, India and exported worldwide with complete shipping and export documentation.

SS 309 Pipes & Tubes | ASTM A312 TP309 Stainless Pipe

Q: What is the UNS number and Werkstoff number for SS 309?

The UNS number for stainless steel 309 is S30900, with corresponding Werkstoff number 1.4828.

Q: What is the difference between SS 309 and SS 309H pipe?

Standard 309 has an unrestricted carbon floor and a maximum of 0.08 percent carbon, while 309H carries a controlled higher carbon range of 0.04 to 0.10 percent, which ASME code requires for assigning elevated-temperature allowable stress values. Standard 309 is generally chosen for easier welding and fabrication, while 309H is specified when a project's design code requires the controlled carbon range.

Q: What is the difference between 309 and 309S stainless steel?

309S is a low-carbon variant of 309, also capped at 0.08 percent maximum carbon. Mill-produced 309 material commonly meets both the standard 309 and 309S requirements simultaneously, so the two designations are often interchangeable unless a specification explicitly calls for 309S.

Q: What is ASTM A312 TP309?

ASTM A312 TP309 is the specification covering seamless and welded austenitic stainless steel pipe in Grade 309, identified by UNS S30900 and Werkstoff Nr. 1.4828, used for high-temperature and corrosive service piping.

Q: What is the difference between 309 and 310 stainless steel pipe?

310 stainless steel contains higher chromium (24 to 26 percent) and nickel (19 to 22 percent) than 309 (22 to 24 percent chromium, 12 to 15 percent nickel), giving 310 a higher maximum continuous service temperature of roughly 2000 degrees Fahrenheit compared with about 1900 degrees Fahrenheit for 309, while 309 offers a more economical option for moderate high-temperature service.

Stainless Steel 309 Pipes & Tubes Supplier, Exporter & Stockist

Amardeep Steel Centre LLP is a manufacturer, exporter and stockist of ASTM A312 TP309 Stainless Steel Pipes & Tubes, available across a range of dimensions, schedules, and surface finishes in both metric and inch sizing. We supply SS 309 Pipes and Tubes in Seamless, Welded, ERW, EFW, SAW, LSAW and DSAW construction, backed by EN 10204 3.1 Mill Test Certificates and full material traceability from heat number through to finished product. SS 309 is widely used in furnace components, boiler baffles, oven linings, fire-box sheets, heat exchangers and other high-temperature containers, as well as in chemical processing, desalination, and fertilizer plant equipment where elevated-temperature oxidation resistance is required.

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What is Stainless Steel 309 Pipe?

Stainless Steel 309 is an austenitic chromium-nickel alloy pipe and tube product covered under ASTM A312 (pipe) and ASTM A213 / A249 / A269 (tube), identified by UNS S30900 and Werkstoff Nr. 1.4828. It is a heat-resisting modification of the standard 300-series alloys, with higher chromium and nickel content than 304, developed for sustained service in high-temperature oxidizing atmospheres.

Looking for the higher-carbon, code-rated variant for elevated-temperature pressure design? See Stainless Steel 309H Pipes & Tubes.

SS 309 Material Overview

Stainless Steel 309 is an austenitic chromium-nickel alloy developed as a heat-resisting modification of the standard 300-series grades. With 22–24% chromium and 12–15% nickel — roughly 5% more chromium than Grade 304.It offers materially better resistance to oxidation and scaling in sustained high-temperature service, while retaining the formability, weldability, and machinability typical of austenitic stainless steels.

309 is produced in two commonly recognized carbon variants: standard 309 (0.08% max carbon, no specified minimum) and the higher-carbon 309H (0.04–0.10% carbon), which ASME design codes require for assigning elevated-temperature allowable stress values on code-stamped pressure piping. Standard 309 the grade on this page is the more commonly stocked, more readily welded and fabricated option, and is the correct specification for the large majority of furnace, kiln, and high-temperature equipment applications that are not governed by an elevated-temperature pressure-design code.

309 does not respond to heat treatment; its strength and hardness can be increased only by cold working. It has good resistance to sulfidation but limited resistance to carburization, and is not recommended for highly carburizing atmospheres.

SS 309 vs 309S vs 309H — Which Grade Do You Need?

All three share the same base chromium-nickel chemistry (22–24% Cr, 12–15% Ni) and differ only in carbon content:

Grade	UNS	Carbon Range	Best suited for
309	S30900	0.08% max (no minimum)	General high-temperature fabrication where ease of welding is the priority
309S	S30908	0.08% max (low-carbon variant)	Applications prioritizing minimal carbide precipitation and weld integrity
309H	S30909	0.04–0.10% (controlled band)	Code-rated elevated-temperature pressure piping where ASME requires a minimum carbon content for stress-allowance qualification

In practice: specify standard 309 (this page) for the majority of furnace, kiln, and high-temperature fabrication work. Specify 309H only where your project's design code or engineering specification explicitly calls for the controlled carbon range. Our team can confirm which grade your purchase order or drawing actually requires before you order.

Stainless Steel 309 Pipes & Tubes Specification

Specification	Detail
Specifications	ASTM A / ASME SA213 / A249 / A269 / A312 / A358
Dimensions	ASTM, ASME and API
Pipe Size	½" NB to 24" NB
Tube Size	½" OD to 12" OD, Gauge: 25 SWG – 10 SWG
Wall Thickness	Schedule 5S to Schedule XXS
Schedule	SCH 10, SCH 20, SCH 30, SCH 40, STD, SCH 60, XS, SCH 80, SCH 120, SCH 140, SCH 160, XXS
Type	Seamless / ERW / Welded / EFW / Fabricated / LSAW
Form	Round, Square, Rectangular, Hydraulic, Hollow Section
Surface Finish	Mill Finish, Pickled & Annealed, Bright Annealed, Polished (on request)
Length	Single Random, Double Random & Cut Length
End	Plain End, Beveled End, Threaded

Note: Pipe sizes are quoted in NB (nominal bore); tube sizes are quoted in OD (outside diameter). Always confirm which sizing convention your project specification uses before placing an order.

Equivalent Grades of Stainless Steel 309

Standard	Designation	Werkstoff Nr.	UNS	EN	AFNOR	JIS	BS	GOST
ASTM / ASME	TP309 / SA312 Gr. TP309	1.4828	S30900	X15CrNiSi20-12	Z17CNS20-12	SUH309	309S24	20KH20N14S2

Production according to national and international standards (ASME, ASTM, API, EN, DNV, etc.)

Chemical Composition of Stainless Steel 309 Seamless & Welded Pipes & Tubes

Grade	C	Mn	Si	P	S	Cr	Ni	Fe
309 min.	–	–	–	–	–	22.0	12.0	Balance
309 max.	0.08	2.0	1.0	0.045	0.03	24.0	15.0	Balance

Standard 309 carries an unrestricted carbon floor and a 0.08% maximum ceiling. The higher, code-mandated carbon band (0.04–0.10%) is reserved for 309H, which qualifies for ASME elevated-temperature allowable stress values that standard 309 does not — see SS 309 vs 309S vs 309H above.

Mechanical Properties ASTM A312/A213/A269 TP309 Stainless Steel Pipes & Tubes

Grade	Tensile Strength (MPa) min	Yield Strength 0.2% Proof (MPa) min	Elongation (% in 50mm) min	Hardness — Rockwell B (HR B) max	Hardness — Brinell (HB) max
309	515	205	35	92	201

Testing, Certification & Documentation

Every batch of SS 309 pipes and tubes is supplied with full material traceability from heat number through to finished product. Standard documentation includes EN 10204 3.1 Mill Test Certificates, with IBR Form III-D available for boiler-code projects in India.

Testing available on request includes:

Positive Material Identification (PMI)
Hydrostatic testing
Chemical and mechanical analysis
Eddy current testing
Flattening and flaring tests
Intergranular corrosion (IGC) testing
Micro / macro examination
Third-party inspection at an agency of the buyer's choice

Referenced standards: ASTM A312, A213, A249, A269, A358, A262, A370, A480, A632, A1016, E527.

See our Testing, Certificates, and Quality Policy pages for full detail, and our Packing & Despatch page for export packaging and documentation standards.

High-Temperature Applications of 309 Pipe

Stainless Steel 309 pipes and tubes are specified in furnace components, boiler baffles, burner assemblies, kiln linings, combustion chambers, oven linings, fire-box sheets, thermal-processing equipment, annealing covers, tube hangers, and automotive exhaust components — anywhere sustained exposure to high-temperature oxidizing atmospheres rules out standard austenitic grades. They are also used in refinery and chemical-process piping, desalination plant equipment, and fertilizer plant components exposed to hot, oxidizing process conditions.

Other Types of Stainless Steel 309 Pipes & Tubes

SS 309 Cold Drawn Pipe Exporter in India	309 SS Schedule 40/40S Pipe Supplier in India
Schedule 80 Stainless Steel 309 Pipes	Thick-Walled SS 309 Pipe Stockist in India
Welded Stainless Steel UNS S30900 Pipe	SS 309 Polished Pipe Price List
Stainless Steel 309 Large Diameter Pipe	ASME SA312 SS 309 Fabricated Pipes
SS 1.4828 Heavy Wall Piping	SUS 309 Hollow Section Square Pipes
SS 309 Oval Pipe	High-Quality SS 309 Round Pipe
SS 309 Bright Annealed Pipes	SS 309 Rectangle Hollow Section Pipes

Export Capability

Amardeep Steel Centre LLP exports SS 309 pipes and tubes worldwide from ready stock held in Mumbai, India, with regular shipments to the United Arab Emirates, Saudi Arabia, the United States, the United Kingdom, Germany, Singapore, South Africa, Nigeria, Australia, and Qatar, alongside project-based supply across the Middle East, Southeast Asia, Africa, Europe, and the Americas. Every export shipment is accompanied by complete shipping documentation, including Certificate of Origin and packing list, with fumigation certificates provided where required.

Frequently Asked Questions - Stainless Steel 309 Pipes & Tubes

What is 309 stainless steel pipe used for?

309 stainless steel pipe is used in high-temperature environments — furnace components, boiler baffles, kiln linings, burners, oven linings, fire-box sheets, and other equipment exposed to sustained heat and oxidizing atmospheres.

What is the UNS number and Werkstoff number for SS 309?

UNS S30900, Werkstoff Nr. 1.4828.

What is the difference between SS 309 and SS 309H pipe?

Standard 309 has an unrestricted carbon floor and an 0.08% maximum ceiling. 309H carries a controlled, higher carbon range (0.04–0.10%) specifically because ASME code requires this minimum carbon level to assign elevated-temperature allowable stress values. Standard 309 is typically chosen for general high-temperature fabrication where easier welding is the priority; 309H is specified when a project's design code requires the controlled carbon range. See our 309H page for full detail.

What is the difference between 309 and 309S stainless steel?

309S (UNS S30908) is a low-carbon variant of 309, also capped at 0.08% maximum carbon. In many cases, mill-produced 309 plate and pipe meets both the standard 309 and 309S grain-size and carbon requirements simultaneously, so the two designations are often interchangeable in practice unless a specification calls out 309S explicitly.

What is ASTM A312 TP309?

ASTM A312 is the specification governing seamless and welded austenitic stainless steel pipe; TP309 is the specific grade designation within it, corresponding to UNS S30900 and Werkstoff Nr. 1.4828. For tube products, the equivalent specifications are ASTM A213 (seamless) and ASTM A249/A269 (welded).

What is the difference between 309 and 310 stainless steel pipe?

310 contains more chromium (24–26%) and nickel (19–22%) than 309 (22–24% Cr, 12–15% Ni), which raises its maximum continuous service temperature to roughly 2000°F versus about 1900°F for 309. 309 is generally the more cost-effective choice when service temperatures stay within its range; 310 is specified for more severe continuous high-temperature or sulfur-bearing service.

What is the difference between 309 and 304 stainless steel pipe?

304 is a general-purpose austenitic grade (18–20% Cr, 8–11% Ni) suited to ambient-to-moderate temperature corrosion resistance. 309's higher chromium and nickel content gives it materially better oxidation resistance at sustained elevated temperatures, making it the correct choice for furnace, kiln, and high-temperature process equipment where 304 would scale or degrade.

What temperature can 309 stainless steel withstand?

Approximately 1900°F (1038°C) under non-cyclic (steady) heat, and approximately 1850°F (1010°C) where the application involves frequent thermal cycling.

Is 309 pipe available in seamless and welded form?

Yes, Amardeep Steel Centre supplies SS 309 pipes and tubes in seamless, ERW (welded), and EFW (fabricated/welded) forms, in round, square, rectangular, and hollow-section profiles.

What sizes are available in stainless steel 309 pipes and tubes?

Pipe sizes run from ½" NB to 24" NB across schedules from SCH 10 through XXS; tube sizes run from ½" OD to 12" OD.

What documentation comes with a 309 pipe order?

EN 10204 3.1 Mill Test Certificates as standard, IBR Form III-D for boiler-code projects in India, PMI testing, and third-party inspection — all available on request.

Do you export stainless steel 309 pipes and tubes outside India?

Yes. Stock is held in Mumbai and shipped worldwide with full export documentation.

Get a Competitive Quote for Stainless Steel 309 Pipes & Tubes

Amardeep Steel Centre supplies SS 309 Pipe & Tube in seamless, welded, ERW, and EFW forms with complete documentation including EN 10204 3.1 MTC, IBR Form III-D, and third-party inspection on request. Ready stock available in Mumbai with worldwide export capability.

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