Austenitic Stainless Steel Grades, Products, Standards & Material Selection

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies austenitic stainless steel for chemical processing, food and pharmaceutical equipment, pressure systems, heat exchangers, architectural fabrication, high-temperature equipment and general industrial applications.

Austenitic grades form the largest stainless steel family and are widely selected because they combine good to excellent corrosion resistance with excellent fabrication and welding characteristics. Standard austenitic stainless steels cannot normally be hardened by conventional heat treatment, but their strength can be increased substantially by cold working. Their low-temperature toughness also makes selected grades suitable for cryogenic applications.

Available supply can include:

Sheet · Plate · Coil · Strip · Pipe · Tube · Round Bar · Flat Bar · Wire · Angle · Custom Profiles

Material, dimensions, surface finish, processing route and inspection requirements should be confirmed according to the selected grade and product standard.

Austenitic stainless steel is a stainless steel family whose microstructure is predominantly austenitic under its intended service or delivery condition.

Nickel, manganese and nitrogen are important austenite-stabilizing elements, while chromium, molybdenum and nitrogen can be used to improve different aspects of corrosion performance.

Commercial austenitic stainless steels are not one single material.

They include several substantially different groups ranging from economical Cr-Mn grades to conventional Cr-Ni grades and highly alloyed materials designed for aggressive corrosion environments.

Outokumpu divides the austenitic family into five broad groups:

This subdivision reflects important differences in alloy design and service performance.

*Exact grade equivalence should always be checked against the applicable purchasing specification rather than assumed solely from commercial cross-reference tables.

304 is one of the primary Cr-Ni stainless steels for general industrial fabrication.

Choose 304L when a low-carbon grade is required for welded construction according to the applicable material specification.

Typical applications include:

• Food equipment
• Storage tanks
• Architectural components
• Industrial fabrication
• Piping components
• General machinery

316 and 316L contain molybdenum, improving resistance to localized corrosion compared with conventional 304 in many environments.

Typical applications include:

• Chemical equipment
• Pharmaceutical equipment
• Food processing
• Heat exchangers
• Process piping
• Coastal industrial equipment

However, 316L should not automatically be described as fully resistant to seawater.

Actual performance depends on chloride concentration, temperature, oxygen availability, deposits, crevices, surface condition and equipment design.

309S and 310S contain higher chromium and nickel levels than conventional 304-type grades and are commonly considered for elevated-temperature and oxidation-resistant applications.

Typical applications include:

• Furnace components
• Heat-treatment equipment
• Burner parts
• Kiln components
• High-temperature supports

Material selection must distinguish between:

oxidation resistance

and

load-bearing creep strength.

These are not the same engineering requirement.

321 is titanium stabilized, while 347 uses niobium stabilization.

These grades are frequently considered where elevated-temperature exposure and resistance to sensitization-related issues are relevant.

ASTM A312 separately identifies higher-carbon H versions including TP321H and TP347H for temperatures where creep and stress-rupture properties become important.

904L is a highly alloyed austenitic stainless steel containing elevated nickel and molybdenum together with copper.

It is commonly evaluated for aggressive chemical processing environments where standard 304 or 316L may not provide sufficient corrosion resistance.

Typical applications include:

• Chemical processing
• Acid handling systems
• Pulp and paper equipment
• Pollution-control equipment
• Process tanks and piping

Selection should always consider:

• Acid type
• Concentration
• Temperature
• Contamination
• Chlorides
• Oxidizing or reducing conditions

254 SMO is a high-performance 6Mo superaustenitic grade designed for severe corrosion environments.

It is typically considered when localized chloride corrosion becomes too severe for conventional 316L and other standard austenitic grades.

Typical applications can include:

• Seawater systems
• Desalination equipment
• Bleaching equipment
• Flue-gas treatment
• Chemical processing
• High-chloride process equipment

Austenitic stainless steel should never be selected simply by ranking grades from “good” to “better”.

The actual corrosion mechanism must first be identified.

Final grade selection depends on actual operating conditions.

Important parameters include:

Temperature · Chloride Concentration · pH · Acid Concentration · Crevice Geometry · Flow Velocity · Oxygen Content · Surface Finish · Welding Condition

Austenitic stainless steels, particularly standard grades, can be susceptible to chloride stress corrosion cracking under unfavorable combinations of tensile stress, chloride exposure and temperature; duplex or other alloy systems may be preferred where this mechanism governs material selection.

A major procurement mistake is to treat a stainless steel grade and a stainless steel product standard as the same thing.

The applicable standard depends on the product form and intended service.

As of August 2026, ASTM identifies A240/A240M-26 as the active edition for applicable stainless plate, sheet and strip, while ASTM A276/A276M-25 covers hot- or cold-finished stainless bars and selected shapes.

ASTM A312/A312M-25 covers seamless, straight-seam welded and heavily cold-worked welded austenitic stainless steel pipe for high-temperature and general corrosive service.

ASTM A479/A479M-25 specifically applies to bars and shapes intended for boiler and pressure-vessel construction and should therefore not be presented as a universal bar standard.

ASTM A580/A580M-23 is the active ASTM specification covering commonly used stainless steel wire forms within its defined scope.

For European flat products, BS EN 10088-2:2024 covers technical delivery conditions for corrosion-resistant stainless steel sheet, plate and strip for general purposes.

Available depending on grade in:

• Hot rolled plate
• Cold rolled sheet
• Heavy plate
• Cut-to-size plate
• Precision sheet

Typical surfaces:

• No.1
• 2B
• BA
• No.4
• Hairline
• Polished
• Mirror where applicable

Available options include:

• Hot rolled coil
• Cold rolled coil
• Slit coil
• Precision strip
• Spring strip
• Custom slit widths

Processing can include:

• Slitting
• Leveling
• Cut-to-length
• Edge conditioning
• Surface finishing

Depending on grade and specification:

• Seamless pipe
• Welded pipe
• Process tube
• Heat exchanger tube
• Sanitary tube
• Structural tube

Available testing should be specified according to the applicable product standard and purchase order.

Available forms can include:

• Round Bar
• Flat Bar
• Square Bar
• Hex Bar
• Bright Bar
• Forged Bar
• Precision Ground Bar

Processing:

• Saw Cutting
• Peeling
• Grinding
• Polishing
• Turning
• Basic Machining

Products can include:

• Spring Wire
• General Purpose Wire
• Cold Heading Wire
• Welding Applications
• Fine Wire
• Custom Diameter Wire

Actual grade and condition availability should be confirmed before ordering.

Products can include:

• Angle Bar
• Channel
• T Section
• Flat Profile
• Custom Formed Profiles

Manufacturing route can vary between:

• Hot rolling
• Cold forming
• Plate forming
• Fabricated or specialty processes

depending on dimensions and grade.

Most conventional austenitic stainless steels are supplied in an annealed or solution-annealed condition depending on the product and applicable specification.

Unlike martensitic stainless steel, conventional austenitic stainless steel is not hardened by quenching and tempering.

Strength can instead be increased through cold deformation or work hardening.

Heat-treatment requirements must be confirmed by:

• Grade
• Product standard
• Section thickness
• Final condition
• Service requirement

High-alloy and high-temperature grades may require different solution-treatment requirements from conventional 304 or 316L.

Austenitic stainless steels generally offer good weldability and formability.

However, welding procedures should consider:

• Base metal grade
• Filler metal
• Heat input
• Interpass temperature
• Joint design
• Shielding gas
• Pickling and passivation
• Final service environment

For demanding corrosion applications, weld surface condition and post-weld cleaning may significantly affect service performance.

Low-carbon grades such as 304L and 316L are frequently selected for welded fabrication where the applicable design and material specification calls for them.

Austenitic stainless steels generally work-harden during machining.

Machining procedures should therefore consider:

• Rigid tooling
• Positive cutting geometry
• Appropriate cutting speed
• Continuous feed
• Adequate cooling

For high-volume machining applications, a free-machining grade such as 303 may be evaluated where its corrosion and service limitations are acceptable.

• 316L
• 317L
• 904L
• 254 SMO

depending on chemical composition and operating conditions.

• 304 / 304L
• 316 / 316L

depending on process chemistry and cleaning conditions.

316L is frequently evaluated for wetted process equipment, piping and hygienic fabrication.

• 309S
• 310S
• 321
• 347

depending on temperature, loading and atmosphere.

• 304
• 316L

depending on atmospheric exposure and chloride conditions.

The good low-temperature toughness of austenitic stainless steels makes selected grades suitable for cryogenic equipment and storage systems.

This table is a preliminary selection guide rather than a substitute for engineering evaluation.

For demanding applications, provide:

Media + Concentration + Temperature + Pressure + Chloride Content + Required Product Form

before final material selection.

Available inspection options can be specified according to product form and purchase order.

Material Traceability

• Heat number identification
• Material grade verification
• MTC review

Chemical Verification

• Mill chemical analysis
• PMI when required

Note:

XRF PMI is useful for alloy identification but should not be described as independently confirming low-carbon L grades solely from carbon content.

Dimensional Inspection

Thickness

• OD
• Wall thickness
• Width
• Length
• Straightness
• Tolerance

Mechanical Testing

According to applicable material specification and purchase order.

Additional Testing

• UT
• ET
• Hydrostatic testing
• Intergranular corrosion testing
• Pitting corrosion testing
• Third-party inspection

where applicable and specifically ordered.

Shaanxi Shangyou Stainless Steel Co., Ltd. can coordinate processing according to product form and project requirements:

• Cut to Size
• Slitting
• Leveling
• Saw Cutting
• Laser Cutting
• Polishing
• Grinding
• Drilling
• Basic Machining
• Custom Fabrication
• Export Packing

Send the required grade, specification, dimensions and quantity for production-route confirmation.

For a faster quotation, please provide:

• Grade: 304L / 316L / 310S / 904L / other
• Product Form: Plate / Coil / Pipe / Bar / Wire / Profile
• Standard: ASTM / ASME / EN / JIS or project specification
• Dimensions: Thickness × Width × Length / OD × WT / Diameter
• Quantity
• Surface Finish
• Heat Treatment Condition
• Testing Requirement
• MTC / EN 10204 Requirement
• Processing Requirement
• Destination Port

The cheapest grade is not always the lowest-cost material for the complete service life.

If you are choosing between 304, 316L, 321, 347, 904L or 254 SMO, send us:

Application · Medium · Concentration · Temperature · Pressure · Chloride Level · Required Product Form

Our team can help narrow the material options and prepare a quotation based on the required product specification.

• Request a Quote
• Send Your Material Specification
• Request MTC 3.1
• Get Cut-to-Size Pricing

Shaanxi Shangyou Stainless Steel Co., Ltd.