316L Stainless Steel (UNS S31603)
Austenitic (low carbon, Mo-bearing) · ASTM A240/A240M · Density 7.98 g/cm³
Type 316L (UNS S31603 / EN 1.4404) is the low-carbon molybdenum-bearing austenitic for sheet, coil, plate, pipe, tube and bar when chloride, chemical or marine-adjacent duty needs more localized-corrosion resistance than the 304/304L family, and welded assemblies will remain as-welded. Carbon is limited to ≤0.030% to reduce sensitization risk in the heat-affected zone versus standard 316 (≤0.08%). Molybdenum (typically 2.00–3.00%) is the pitting upgrade — not unlimited seawater capability — and dual 316/316L certification is valid only when the heat and MTC meet both chemistry and strength rules.
Quotation brief
Quote 316L When
Quote 316L when the RFQ names sheet, coil, plate, pipe, tube or bar in the molybdenum-bearing 316 corrosion family, and welded assemblies will remain as-welded so sensitization risk in the heat-affected zone matters. Low carbon (≤0.030%) is why buyers prefer 316L over standard 316 for fabrication left as-welded; molybdenum (typically 2.00–3.00%) is why 316L outranks 304/304L for many chloride, chemical and marine-adjacent duties. It is not automatic seawater approval and not a duplex substitute — permanent immersion, hot brine or severe crevices may still point to 2205 after review. Annealed flat product under ASTM A240 is the usual starting summary; dual 316/316L chemistry, sanitary tubing roughness and non-flat product standards must be ordered explicitly. Keep hygienic tubing RFQ detail on the existing sanitary tubing blog and industry framing on application pages without moving alloy acceptance language off this grade page.
Best fit
- As-welded chemical process pipe, vessels and fabrications that need Mo-bearing pitting resistance with the low-carbon HAZ limit.
- Annealed sheet, coil and plate orders that specify S31603 / EN 1.4404 chemistry for chloride or cleaning-chemistry duty beyond 304L.
- Coastal and marine-adjacent hardware where 304/304L is inadequate and the actual chloride-temperature envelope still fits 316L after review.
Limits to check
- Permanent seawater immersion, hot concentrated brine and severe crevices can still pit 316L — screen duplex 2205 or higher alloys instead of relying on a marine label.
- Annealed A240 strength minima are slightly lower than standard 316; dual 316/316L certification is valid only when the MTC proves both chemistry and strength.
- A flat-product A240 summary does not define pipe, sanitary tube, bar or fitting acceptance, nor Ra/electropolish qualification — name those standards and documents separately.
Quoted product forms
Quoted product forms for 316L Stainless Steel (UNS S31603)
We quote 316L Stainless Steel as sheet / plate, coil / strip, pipe / tube, bar against the named product standard.
- Traceability: heat or lot identity plus the inspection document named in the RFQ (EN 10204 3.1 when that route supports it).
- Processing: decoiling, cutting, polishing, shearing and beveling as ordered.
- Next step: send product form, size and quantity; we quote the supply route.
Chemical Composition (wt%)
| C | Mn | Si | Cr | Ni | Mo | P | S | N |
|---|---|---|---|---|---|---|---|---|
| ≤0.030 | ≤2.00 | ≤0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | ≤0.045 | ≤0.030 | ≤0.10 |
Single values are maximums unless a range is shown. Balance: Fe. Per ASTM A240/A240M.
Mechanical Properties
| Tensile strength | ≥485 MPa (70 ksi) |
|---|---|
| Yield strength (0.2%) | ≥170 MPa (25 ksi) |
| Elongation (50 mm) | ≥40% |
| Hardness | ≤217 HBW |
Room-temperature minimum values are summarized for annealed flat product under ASTM A240/A240M unless a condition is named in the property label; product form and thickness can change the requirement.
Properties by Condition
316L Annealed (standard flat-product supply)
The usual mill condition for ASTM A240 sheet, plate, coil and strip — maximum ductility for forming before intentional cold work, with the low-carbon and molybdenum chemistry retained for welded chloride-service assemblies.
| Tensile strength | ≥485 MPa (70 ksi) |
|---|---|
| Yield strength (0.2%) | ≥170 MPa (25 ksi) |
| Elongation | ≥40% |
| Hardness | ≤217 HBW |
Dual-certified 316/316L (when ordered and proven on MTC)
Market practice often supplies heats that meet 316L carbon (≤0.030%) and 316 annealed strength minima together. Accept only when the purchase order and heat-specific MTC demonstrate both chemistry and mechanical rules for the ordered product standard.
| Carbon | ≤0.030% (316L limit) |
|---|---|
| Tensile / yield | Must also meet the applicable 316 minima named on the order |
| Ordering note | Write dual 316/316L explicitly; do not infer from a grade stamp alone |
Physical Properties & Structure
| Density | 7.98 g/cm³ |
|---|---|
| Magnetic response | Essentially non-magnetic after solution annealing; cold work can introduce a measurable magnetic response. |
| Microstructure | Austenitic (low carbon, Mo-bearing) |
Corrosion Resistance & Limits
- Molybdenum-bearing 316L improves localized-corrosion resistance versus the 304/304L chromium-nickel family in many chloride, chemical-cleaning and coastal exposures; lower carbon reduces sensitization risk in suitable as-welded construction but does not raise pitting resistance beyond the 316 alloy family.
- Permanent seawater immersion, hot concentrated brine, tight crevices, deposits and poorly drained wet-dry cycling can still pit 316L — screen duplex 2205 or higher alloys after engineering review rather than relying on a marine-grade label.
- Review chlorides, temperature, pH, deposits, crevices, drainage, cleaning chemistry, weld heat tint and surface finish for the actual as-welded component. A grade designation alone is not a service-life guarantee.
Fabrication & Heat Treatment
| Welding | Generally weldable with a qualified austenitic procedure, matching or over-alloyed filler where required, controlled heat input, purge on tubular joints and heat-tint removal when corrosion service demands it. The ≤0.030% carbon limit reduces sensitization (IGC) risk in the HAZ for as-welded tanks, pipe and structural weldments, but it does not qualify the WPS, filler or surface restoration — and Mo alloying is still not a substitute for duplex or higher alloys in severe chloride envelopes. |
|---|---|
| Forming | Annealed 316L sheet and strip draw and bend well, but the alloy work-hardens during forming — tooling load, springback, bend direction, draw ratio and any intermediate anneal must be proven on the actual gauge and reduction route. |
| Machining | Use rigid tooling, positive feeds and controlled cutting heat to avoid a work-hardened surface; qualify the route on the delivered condition. Free-machining sulfur grades require separate corrosion and welding review. |
| Heat treatment | Solution annealing with rapid cooling restores the intended annealed austenitic condition after suitable cold work or fabrication where applicable. Conventional quench-and-temper treatment does not through-harden austenitic 316L; do not rely on post-weld anneal unless the project actually schedules it. |
Equivalent Grades
The closest international equivalents of 316L Stainless Steel are 1.4404 (X2CrNiMo17-12-2) in the EN system, SUS316L in the JIS system, 022Cr17Ni12Mo2 in the GB system, 316 / UNS S31600 / EN 1.4401 (standard-carbon sibling — not automatic substitute; dual cert only when MTC proves both) in the Related system.
These are common corresponding designations, not unconditional substitutes. Verify chemistry, mechanical properties, product standard, delivery condition, dimensions and project approval before changing designation.
| System | Designation |
|---|---|
| UNS | S31603 |
| EN | 1.4404 (X2CrNiMo17-12-2) |
| JIS | SUS316L |
| GB | 022Cr17Ni12Mo2 |
| Related | 316 / UNS S31600 / EN 1.4401 (standard-carbon sibling — not automatic substitute; dual cert only when MTC proves both) |
Ordering Checks for 316L
- State UNS S31603 or EN 1.4404, product form (sheet/coil/plate/pipe/tube/bar), ASTM A240 or the governing standard edition, thickness or size, finish and annealed condition.
- Define chloride chemistry, temperature, crevices, cleaning chemicals and whether 304/304L, 316 or duplex 2205 is the correct alloy family before locking 316L.
- Specify any dual 316/316L requirement explicitly, plus finish (2B, BA, No.4, polished tube, etc.), critical face, heat-tint removal and passivation expectations.
- Request heat-specific MTC / EN 10204 3.1 (or the inspection document named in the RFQ), chemistry, tensile results, dimensions and lot traceability — see the site EN 10204 guide when writing the document list.
Reference Product Forms & Dimensional Ranges
Common reference product forms for 316l stainless steel: Sheet / Plate, Coil / Strip, Pipe / Tube, Bar.
| Finishes | No.1, 2B, BA, No.4, hairline, 8K mirror |
|---|---|
| Sheet / coil thickness | 0.3–6.0 mm |
| Plate thickness | 6–80 mm |
| Pipe / tube / bar | Quoted to the governing product standard (for example ASTM A312, A269, A270, A554 or A276) with size, schedule or diameter named in the RFQ |
Common surface and delivery options
- No.1, 2B, BA or mechanically polished finish when supported by the product route
- Annealed and pickled coil/strip, or polished tube finish as specified
- Protective film, critical face and agreed surface sample for visible or cleanable parts
- Hot rolled, peeled, bright drawn, ground or polished bar condition according to tolerance
These published ranges are engineering references, not a live-stock or production-capability promise. Send the required product form, dimensions, condition and finish; we quote the matching supply route.
Browse related product hubs:Sheet & plate,Coil & strip,Pipe & tube,Bar & rod.
Typical Applications
- Chemical process piping, tanks and fabricated equipment after chloride review
- Coastal and marine-adjacent hardware where 304/304L pitting resistance is inadequate
- As-welded vessels and pipe systems specifying low-carbon HAZ resistance with Mo alloying
- Food and cleanable process equipment when molybdenum is justified by cleaning chemistry
- Pharmaceutical or sanitary-adjacent fabrications — finish and tubing detail on dedicated guides
316L Products We Export
316L Stainless Steel Sheet
316/316L stainless sheet for chloride and chemical service in 2B, BA and brushed finishes. Common inquiry range 0.3–6.0 mm, 1000/1219/1500 mm, cut to size.
View details →
316L Stainless Steel Seamless Pipe
Seamless 316L ASTM A312 pipe, pickled and annealed. Common inquiry range NPS 1/8–24, Sch 5S–XXS, 6 m or cut-to-length, with quoted tests and heat identity.
View details →
316L Compared With Other Grades
Related buyer guides:
Frequently Asked Questions
What are 316L stainless steel properties, hardness and strength?
For annealed flat product summarized under ASTM A240/A240M, Type 316L (UNS S31603 / EN 1.4404) typically lists minimum tensile ≥485 MPa (70 ksi), 0.2% yield ≥170 MPa (25 ksi) and elongation ≥40%, with hardness capped around ≤217 HBW. Carbon is limited to ≤0.030% and molybdenum is typically 2.00–3.00%. These are room-temperature engineering minima for the annealed condition — cold work, tubular standards (A312, A269, A270) and bar (A276) change hardness and strength. Confirm chemistry, hardness and tensile results on the MTC before approval; do not treat displayed tables as contractual acceptance limits.
What are common 316L equivalents (EN 1.4404, UNS S31603, 316L Stahl)?
Common corresponding designations include UNS S31603, EN 1.4404 (X2CrNiMo17-12-2), JIS SUS316L and GB 022Cr17Ni12Mo2. German-language buyers often search “316L Stahl” or “316L Edelstahl” for the same molybdenum-bearing low-carbon austenitic. Naming an equivalent does not replace the product standard, dual-cert rules or finish requirements — verify chemistry and mechanical results on the heat-specific MTC before substituting designations.
How do 316L, 304/304L and 2205 differ for chloride and chemical service?
304/304L share a chromium-nickel corrosion profile without intentional molybdenum; choose them when chlorides and cleaning chemistry stay within that family after review. 316L adds Mo for improved resistance to pitting and crevice attack in many chemical, coastal and marine-adjacent duties, while the L-carbon limit supports as-welded HAZ integrity versus standard 316. Duplex 2205 is the next common step when higher annealed yield strength and tougher chloride / SCC screening are required and duplex welding controls are available — it is not an automatic upgrade from a 316L stamp.
When does 316L sanitary or biopharma work stay on this grade page vs other URLs?
This grade page owns alloy selection, A240-family chemistry/mechanical summary, equivalents and RFQ checks for Mo-bearing low-carbon 316L sheet, plate, pipe and bar. Hygienic tubing roughness, ASTM A270 detail and tri-clamp RFQ language belong on the ASTM A270 vs A269 sanitary tubing guide and the 316L sanitary tubing specification guide. Broader pharmaceutical / biotechnology equipment context may land on the site pharmaceutical application page — keep alloy and mill-product acceptance language here.
Published by Tsingshan (Shandong) Iron & Steel Co., Ltd..Sources, update policy and technical limitations.
Quote request
Get a 316L Stainless Steel Quotation
Send the product, grade and quantity you already have. We will complete the specification and quote the supply route.