316 Stainless Steel (UNS S31600)
Austenitic (Mo-bearing) · ASTM A240/A240M · Density 7.98 g/cm³
Type 316 (UNS S31600) is an austenitic stainless steel alloyed with 2–3% molybdenum for improved resistance to pitting and crevice corrosion in chloride environments. It is the second most common stainless grade after 304, used in marine, chemical processing and medical applications.
Chemical Composition (wt%)
| C | Mn | Si | Cr | Ni | Mo | P | S |
|---|---|---|---|---|---|---|---|
| ≤0.08 | ≤2.00 | ≤0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | ≤0.045 | ≤0.030 |
Single values are maximums unless a range is shown. Balance: Fe. Per ASTM A240/A240M.
Mechanical Properties
| Tensile strength | ≥515 MPa (75 ksi) |
|---|---|
| Yield strength (0.2%) | ≥205 MPa (30 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.
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 (Mo-bearing) |
Corrosion Resistance & Limits
- General corrosion resistance comes from the chromium-rich passive film; nickel, molybdenum, nitrogen and copper change performance by grade.
- Check chlorides, temperature, crevices, deposits, process chemistry and cleaning conditions. A grade designation alone is not a service-life guarantee.
Fabrication & Heat Treatment
| Welding | Generally weldable with a qualified procedure and matching or over-alloyed filler where required; remove heat tint when corrosion service demands it. |
|---|---|
| Forming | Good ductility is typical, but rapid work hardening increases forming load and springback; bend radius and intermediate annealing depend on grade and reduction. |
| Machining | Use rigid tooling, positive feeds and controlled heat because the material work-hardens; free-machining grades require separate corrosion and welding review. |
| Heat treatment | Solution annealing and rapid cooling restore the intended condition where applicable. Austenitic grades are not hardened by conventional quench-and-temper treatment. |
Equivalent Grades
The closest international equivalents of 316 Stainless Steel are 1.4401 (X5CrNiMo17-12-2) in the EN system, SUS316 in the JIS system, 06Cr17Ni12Mo2 in the GB 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 | S31600 |
| EN | 1.4401 (X5CrNiMo17-12-2) |
| JIS | SUS316 |
| GB | 06Cr17Ni12Mo2 |
Reference Product Forms & Dimensional Ranges
Common reference product forms for 316 stainless steel: Sheet / Plate, Coil / Strip, Pipe / Tube, Bar.
| Finishes | No.1, 2B, BA, No.4, hairline |
|---|---|
| Sheet / coil thickness | 0.3–6.0 mm |
| Plate thickness | 6–80 mm |
Common surface and delivery options: No.1, 2B, BA or mechanically polished finish when supported by the product route; Annealed and pickled, descaled or polished tube finish as specified; 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. Confirm the required product form, dimensions, condition, finish and supply route in the quotation.
Typical Applications
- Marine hardware and coastal architecture
- Chemical processing equipment
- Pharmaceutical and medical devices
- Desalination and water treatment
316 Products We Export
Frequently Asked Questions
What makes 316 better than 304 for marine use?
The 2–3% molybdenum addition. Molybdenum raises resistance to pitting and crevice corrosion caused by chlorides — salt air, seawater, de-icing salt and many process chemicals — where 304 would show rust staining or pitting.
Is 316 stainless steel magnetic?
No, in the annealed condition 316 is austenitic and essentially non-magnetic, and it stays less magnetic than 304 after cold working because its austenite is more stable.
316 or 316L — which should I buy?
For welded construction, 316L's carbon limit reduces sensitization risk. Material may be dual-certified 316/316L when it meets both chemistry and strength requirements, but the MTC and ordered product standard must confirm both designations.
316 Compared With Other Grades
Organizational author: Tsingshan (Shandong) Iron & Steel Co., Ltd..Review method, status and limitations.
Other stainless steel grades:
304304L316L201321310S4104302205202301309S316Ti347904L409L4204394414442507303317L254 SMO440C17-4 PH2304
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