Stainless steel / UNS S31603
316L is the low-carbon version of 316 and the standard choice for welded molybdenum-bearing stainless construction. It is often dual-certified 316/316L.
- UNS S31603
- W.Nr. 1.4404
- Spec ASTM A240
- Density 7.98 g/cm³
Also known as / equivalents
| System | Designation |
|---|---|
| UNS | S31603 |
| W.Nr. | 1.4404 |
| EN | X2CrNiMo17-12-2 |
| JIS | SUS316L |
| Also known as | AISI 316L, 1.4404, SUS316L |
Chemical composition
| Element | Min % | Max % |
|---|---|---|
| C | — | 0.030 |
| Mn | — | 2.00 |
| P | — | 0.045 |
| S | — | 0.030 |
| Si | — | 0.75 |
| Cr | 16.0 | 18.0 |
| Ni | 10.0 | 14.0 |
| Mo | 2.00 | 3.00 |
| N | — | 0.10 |
| Fe | Bal. | — |
Mechanical properties
| Property | Value |
|---|---|
| Tensile strength (min) | 485 MPa (70.3 ksi) |
| Yield strength, 0.2% offset (min) | 170 MPa (24.7 ksi) |
| Elongation in 50 mm (min) | 40 % |
| Hardness | 217 HB max |
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.98 g/cm³ | 0.288 lb/in³ |
| Magnetic response | Non-magnetic when annealed; may become slightly magnetic after cold work | — |
Available forms & specifications
| Form | Specification | Size range |
|---|---|---|
| Sheets, plates & coils | ASTM A240 / ASME SA240 | 0.3 mm – 6 mm |
| Seamless & welded pipe | ASTM A312 / ASME SA312 | 1/8" – 24" NB |
| Tubes | ASTM A213, A249, A269 | 1/8" – 24" NB |
| Bars & rods | ASTM A276, A479 | 3 mm – 500 mm |
| Flanges & forgings | ASTM A182 / ASME SA182 | 1/2" – 48" NB (larger on request) |
| Buttweld fittings | ASTM A403 / ASME SA403 | 1/2" – 48" NB |
| Fasteners | ASTM A193 / A194, F593 / F594 | M3 – M56 |
Corrosion & temperature resistance
Corrosion resistance rises with chromium, molybdenum and nitrogen: 304 handles general atmospheric and food-contact service, 316/317 add resistance to chlorides and pitting, 904L handles strong reducing acids, and stabilised 321/347 resist intergranular attack after welding or high-temperature exposure.
Applications
SS 316L: Process piping, pharma, offshore, food. Process piping, tanks and vessels, heat exchangers, food, dairy and pharmaceutical equipment, architectural work and general engineering.
SS 316L vs SS 316
| SS 316L | SS 316 | |
|---|---|---|
| UNS | S31603 | S31600 |
| Key property | Low-carbon molybdenum grade for welding | Molybdenum-bearing, chloride resistant |
| Typical use | Process piping, pharma, offshore, food | Marine, chemical, pharmaceutical equipment |
| Cr (wt %) | 16.0–18.0 | 16.0–18.0 |
| Ni (wt %) | 10.0–14.0 | 10.0–14.0 |
| Mo (wt %) | 2.00–3.00 | 2.00–3.00 |
| C (wt %) | ≤ 0.030 | ≤ 0.08 |
| Tensile / yield (min, MPa) | 485 / 170 | 515 / 205 |
Frequently asked questions
What is the UNS number of SS 316L?
SS 316L is designated UNS S31603 (W.Nr. 1.4404, EN X2CrNiMo17-12-2).
What is SS 316L used for?
Low-carbon molybdenum grade for welding. Typical uses: process piping, pharma, offshore, food.
Is SS 316L magnetic?
Non-magnetic when annealed; may become slightly magnetic after cold work.
In which forms can I buy SS 316L from Rajkamal Metals?
Coils & Strips, Sheets & Plates, Pipes & Tubes, Round Bars & Rods, Structural Sections, Flanges, Buttweld Fittings, Socket Weld & Threaded Fittings, Fasteners, Ferrule / Instrumentation Fittings, Dairy Fittings, Dish Ends, SS Tanks, Custom Orders. Sizes as per standard; other sizes on request.
Do you supply a Mill Test Certificate with SS 316L?
Yes. Actual values are given in the Mill Test Certificate (EN 10204 3.1) supplied with each order.
What is the difference between SS 316L and SS 316?
SS 316L: low-carbon molybdenum grade for welding. SS 316: molybdenum-bearing, chloride resistant. See the comparison table on this page.
Last updated: 30 October 2026. Grade names identify the supply range; designations are not engineering equivalents. Availability, make, origin and documentation are confirmed at quotation.
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