Stainless Steel 316 / 316L
UNS S31600 / S31603 · The chloride-resistant workhorse
SS 316 adds 2–3% molybdenum to the 18/8 base, which markedly improves resistance to pitting and crevice corrosion in chloride environments. It is the default grade for marine, coastal and chemical process service. 316L, the low-carbon variant, is specified for welded construction.
When to specify SS 316
Choose 316 or 316L wherever chlorides are present — coastal installations, seawater cooling, brines, bleaches and many process chemicals — and in pharmaceutical and food plant where aggressive cleaning chemicals are used. If chloride levels or temperatures are higher still, or if higher strength would allow a lighter section, consider Duplex 2205.
Chemical Composition (%)
Composition and mechanical values are the limits set by the governing ASTM specification and are given for reference. The mill test certificate supplied with your consignment carries the actual heat analysis.
| Element | 316 (S31600) | 316L (S31603) |
|---|---|---|
| Carbon | 0.08 max | 0.030 max |
| Chromium | 16.0 – 18.0 | 16.0 – 18.0 |
| Nickel | 10.0 – 14.0 | 10.0 – 14.0 |
| Molybdenum | 2.00 – 3.00 | 2.00 – 3.00 |
| Manganese | 2.00 max | 2.00 max |
| Silicon | 0.75 max | 0.75 max |
| Phosphorus | 0.045 max | 0.045 max |
| Sulphur | 0.030 max | 0.030 max |
Mechanical & Physical Properties
| Property | 316 | 316L |
|---|---|---|
| Tensile strength | 515 MPa min | 485 MPa min |
| Yield strength (0.2%) | 205 MPa min | 170 MPa min |
| Elongation in 50 mm | 40% min | 40% min |
| Hardness | 217 HB / 95 HRB max | 217 HB / 95 HRB max |
| Density | 8.00 g/cm³ | 8.00 g/cm³ |
Governing Standards
| Standard | Covers |
|---|---|
| ASTM A312 / A358 | Seamless and welded pipe |
| ASTM A213 / A269 | Tube |
| ASTM A240 | Plate, sheet and coil |
| ASTM A276 / A479 | Bar and shapes |
| ASTM A403 WP316/316L | Buttweld fittings |
| ASTM A182 F316/F316L | Forged fittings and flanges |
Equivalent Designations
| Standard | Designation |
|---|---|
| EN | 1.4401 (316) / 1.4404 (316L) |
| JIS | SUS 316 / SUS 316L |
| GB | 06Cr17Ni12Mo2 / 022Cr17Ni12Mo2 |
| UNS | S31600 / S31603 |
Typical Applications
- Marine and coastal piping and structures
- Chemical and petrochemical process lines
- Pharmaceutical and high-purity process equipment
- Heat exchangers in brackish or chloride-bearing water
- Food processing where aggressive cleaning agents are used
Industries Served
- Oil & Gas
- Chemical
- Marine
- Pharmaceutical
- Food & Dairy
- Power
SS 316 Products We Supply
Available in the forms below, minimum order quantity 5 kg, with a mill test certificate to EN 10204 3.1 traceable to the heat number.
- SS 316 Pipes & Tubes→
- SS 316 Buttweld Fittings→
- SS 316 Forged Socketweld & Screwed Fittings→
- SS 316 Flanges→
- SS 316 Sheets, Plates & Coils→
- SS 316 Fasteners & Nut Bolts→
- SS 316 Valves→
- SS 316 Round, Square & Hex Bars→
- SS 316 Dairy Fittings→
- SS 316 Stainless Steel Bends→
- SS 316 Electro Polish Fittings→
- SS 316 Stainless Steel Flats→
- SS 316 Channels & Angles→
Need SS 316 in a form not listed above? We source to requirement — and we will confirm availability and lead time.
SS 316 by product form
Governing standards, dimensions and stock availability for each form.
SS 316 — Frequently Asked Questions
- Is 316 always better than 304?
- Better in chlorides, not universally. The molybdenum in 316 buys pitting resistance and costs roughly 25–40% more. In dry indoor service, freshwater or architectural work away from the coast, 304 performs identically and specifying 316 simply raises the bill. Choose on the environment, not on the grade number.
- What does the "L" mean and when do I need it?
- L denotes low carbon — 0.030% maximum instead of 0.08%. It matters when the component is welded: lower carbon suppresses chromium carbide precipitation in the heat-affected zone and protects against intergranular attack. For welded pipe, fittings and fabricated assemblies specify 316L. Dual-certified 316/316L material, which meets both, is common and usually the practical choice.
- Does 316 resist seawater indefinitely?
- No. 316 is suitable for many marine applications but will pit in stagnant or warm seawater, particularly in crevices under gaskets and deposits. For continuous seawater immersion, super duplex or a nickel alloy is the correct selection.
Send your SS 316 requirement
Tell us the form, size, quantity and standard and our technical team will confirm stock and send a firm price. Minimum order quantity 5 kg, mill test certificates supplied as standard.