High-chromium, high-nickel austenitic stainless steel developed for elevated-temperature and oxidation-resistant applications.
Material gradeStainless Steel Grades
/ 01 — TECHNICAL OVERVIEW
Stainless Steel 309S
Nesco Pipe & Tubes is a manufacturer, supplier, stockist and exporter of Stainless Steel 309S (UNS S30908), offering pipes, tubes, flanges, butt weld fittings, sheets, plates, coils and round bars in specified dimensions, finishes, conditions and testing requirements for industrial and project applications. Availability and applicable standards are confirmed against the customer’s purchase specification.
Stainless Steel 309S is a high-chromium, high-nickel austenitic stainless steel developed for elevated-temperature service and resistance to oxidation. Its higher chromium and nickel content compared with common austenitic grades provides improved performance in high-temperature and oxidising environments.
309S is commonly selected for furnace components, heat-treatment equipment, heat shields, combustion-related equipment and other applications involving elevated temperatures and oxidation.
The correct material depends on more than corrosion resistance alone. Temperature, pressure, atmosphere, thermal cycling, chemistry, erosion, fabrication route, weldability, mechanical strength, product form, code requirements and lifecycle cost should be reviewed together. Final grade selection remains with the customer’s qualified engineer, designer or material specialist.
How it is made
01
Steelmaking and refining establish the required 309S chemistry, including controlled chromium, nickel and carbon levels.
02
The alloy is cast and hot worked into billet, slab or other feedstock for the selected product form.
03
Hot/cold processing creates pipe, tube, flat product, bar, flange or fitting geometry.
04
Solution annealing and controlled processing develop the required metallurgical condition and mechanical properties.
05
Descaling, pickling, machining or polishing may be carried out, followed by dimensional inspection, traceability and certification.
Request reviewed quotation Material documents on request
/ 02 — PRODUCT DETAIL
Built around the specification.
Key characteristics and commonly referenced standards for Stainless Steel 309S.
Key features01 02 03 04 05
Lower-carbon 309S designation intended to reduce susceptibility to sensitisation compared with the higher-carbon 309 grade.
Available across multiple product forms subject to specification, dimensions and availability.
Heat-wise traceability and MTC support.
PMI, applicable NDT and third-party inspection options when specified.
Common specification references
STD
ASTM A240/A240M — Plate, sheet and strip
STD
ASTM A276/A276M and A479/A479M — Stainless steel bars and shapes
STD
ASTM A312/A312M — Austenitic stainless steel pipe
STD
ASTM A213/A213M, A249/A249M and A269/A269M — Product-specific austenitic stainless steel tube/tubing
STD
ASTM A182/A182M and A403/A403M — Forged flanges/pressure components and wrought austenitic stainless steel fittings
STD
Applicable EN product/material standards — European stainless steel requirements
/ 03 — GRADE & MATERIAL IDENTITY
Grades matched to the service.
The specified material is reviewed against the complete grade, product form, governing standard, condition and service requirements.
ParameterDetails
Specified GradeStainless Steel 309S
UNSS30908
Alloy FamilyAustenitic Stainless Steel
Key Alloying FeatureHigh-chromium, high-nickel austenitic stainless steel
Key Distinction309S is the lower-carbon version of 309, commonly selected where reduced susceptibility to sensitisation is required
Material SelectionBased on service conditions and the applicable product specification
/ 04 — SUPPLY & CUSTOMISATION
Available forms and enquiry basis.
Pipes, tubes, flanges, butt weld fittings, sheets and plates, coils and round bars.
ParameterTypical Options
01Available Forms
Pipes, Tubes, Flanges, Butt Weld Fittings, Sheets, Plates, Coils, Round Bars
02Product Standard
Applicable material/product standard
03Supply Condition
Solution annealed, hot finished, cold worked, or other specified condition
04Dimensions
Product-form dimensions, tolerances, cut lengths, end/edge preparation
05Testing
PMI, mechanical, corrosion, NDT or supplementary testing as required
06Documentation
MTC and inspection reports as specified
07Identification
Heat number, grade, size and other agreed identification
08Enquiry Basis
Grade/UNS, product form, standard, dimensions, quantity and destination
/ 05 — DIMENSIONS & SIZE RANGE
Dimensions aligned to the manufacturing route.
Dimensions and supply options are confirmed against the exact grade, product form, applicable specification and manufacturing availability.
Product FormDimensions / ConfigurationSupply OptionsReference
PipesNPS/OD, schedule/wall thickness, length, end configurationSeamless/welded, heat treated/finishedApplicable material + dimensional standard
TubesOD, wall thickness, length/coil, U-bendSeamless/welded, annealed/specified finishApplicable ASTM/EN product standard
Flat ProductsThickness, width, length/coilHot/cold rolled, annealed, pickled/polishedApplicable flat-product material standard
Bars / ForgingsDiameter/profile, tolerance, cut lengthHot finished, forged, cold finished, machinedApplicable bar/forging standard
/ 06 — MANUFACTURING STANDARDS
Standards aligned for every order.
The material standard, dimensional standard and project requirements should be stated separately.
309S product-standard references
StandardWhat it covers
ASTM A240/A240MStainless steel plate, sheet and strip
ASTM A276/A276MStainless steel bars and shapes
ASTM A479/A479MStainless steel bars/shapes for pressure vessels and related service
ASTM A312/A312MStainless steel pipe
ASTM A213/A213MSeamless austenitic boiler, superheater and heat-exchanger tubes
ASTM A249/A249MWelded austenitic boiler, heat-exchanger and condenser tubes
ASTM A269/A269MAustenitic stainless tubing for general service
ASTM A182/A182MForged/rolled stainless steel flanges and pressure components
ASTM A403/A403MWrought austenitic stainless steel fittings
Applicable EN standardEuropean product/material requirements
/ 07 — REFERENCE MATERIAL DATA
309S material reference.
A concise engineering identity for procurement. Exact chemical limits and mechanical acceptance values vary by product form, size, condition and specification edition; the certified MTC governs supplied material.
Chemistry and alloy identityPrincipal alloying profile · certification limits follow the ordered standard
Material referenceTechnical profile
Grade / designation309S
Alloying systemHigh-chromium, high-nickel austenitic stainless with restricted carbon.
Certification basisHeat analysis and product requirements are certified against the exact material specification stated on the purchase order.
Mechanical-property basisProduct-form and condition dependent · verify certified values
Property basisSupply requirement
Mechanical profileTensile, yield, elongation and hardness depend on exact grade, product form, thickness and heat-treatment condition.
Acceptance valuesUse the tensile, yield, elongation and hardness limits in the ordered product-form standard and specified condition.
CertificationActual heat/lot results are reported on the agreed material test certificate.
/ 08 — INSPECTION & TESTING
Evidence before dispatch.
01Grade/UNS/product standard verification
02Heat-number traceability and MTC review
03PMI against specified alloy/applicable material specification
04Dimensional, tolerance and surface-condition inspection
05Mechanical and hardness testing according to applicable product specification when specified
06Corrosion, microstructure, intergranular or other supplementary testing when required
07Applicable NDT and third-party witnessing against the approved inspection plan
Testing requirements are applied according to the applicable material/product standard, purchase specification and customer/project requirements.
/ 09 — PACKAGING & MARKING
Protected and traceable.
01Product-form-specific protection for machined faces, surfaces and ends.
02Heat-wise segregation and durable grade identification.
03Clean, non-contaminating separators/protective materials where required.
04Moisture-resistant wrapping/export packing where required.
05Wooden cases/crates where required.
06Identification labels can include grade, heat number, size, dimensions, quantity and PO/project reference, as applicable.
Packaging and marking can be adapted to customer, project and export requirements.
/ 10 — APPLICATIONS & INDUSTRIES
Engineered for demanding service environments.
From process plants to marine systems, NESCO coordinates material, dimensions and documentation around the operating conditions of each application.
01
Chemical processing02
Oil and gas03
Power generation04
Marine systems05
Heat exchangers06
Industrial fabricationIndustries servedOne supply partner across critical sectors.
Chemical processingOil & gasPower generationMarineHeat exchangersProcess equipmentGeneral engineering
/ 11 — WHY NESCO PIPE & TUBES
Built for buyers who cannot leave details to chance.
From specification review to export documentation, NESCO coordinates the technical and commercial details as one complete supply requirement.
01
Specification control
NESCO reviews the grade, product standard, dimensions, condition and acceptance criteria as one coordinated requirement.
02
Multi-material sourcing
Stainless steel, duplex, nickel alloy, copper-nickel and titanium requirements can be combined within one project enquiry.
03
Traceable documentation
Heat numbers, MTCs and agreed inspection records are aligned with the purchase order before dispatch.
04
Inspection coordination
PMI, dimensional checks, NDT and third-party witnessing can be arranged against an approved inspection plan.
05
Value-added processing
Cutting, machining, end preparation, polishing or protective finishing can be reviewed with the base material supply.
06
Export-ready packing
Identification, surface protection and packing are planned around product geometry and the final transport route.
07
Responsive RFQ review
Technical and commercial inputs are consolidated early so queries are resolved before quotation and production.
08
One accountable supply desk
NESCO provides a single contact for material, processing, documentation, packing and delivery coordination.
/ 12 — FREQUENTLY ASKED QUESTIONS
Clear answers before you specify.
Quick guidance on product selection, standards, dimensions, inspection and documentation. For project-specific requirements, NESCO will review the complete enquiry with your team.
01What product forms are available in 309S?
Availability can include pipes, tubes, flanges, fittings, sheets, plates, coils and bars, but each form must be confirmed against its own material standard and production range.
02What standard should be specified for 309S?
State both the exact grade/UNS and the product-form material standard. A plate specification cannot be assumed to cover pipe, tube, bar, flange or fitting supply.
03Can NESCO provide chemical and mechanical certificates?
Yes. An agreed material test certificate can report heat analysis and mechanical results required by the ordered specification.
04Can another grade be substituted?
Only with written approval from the responsible engineer after reviewing corrosion, strength, temperature, fabrication and code requirements.
05What information produces the fastest quotation?
Provide grade/UNS, product form, standard, size, condition, quantity, tests, certification and delivery destination.
/ 13 — REQUEST FOR QUOTATION Nesco direct sales desk
Ready to source?Start with the details you already have.
Our team will review the grade, dimensions, testing and delivery requirements together.