Stainless 316L (UNS S31603)
Stainless 316L (UNS S31603) — Low-carbon 316; the most specified stainless grade for process plants.
| UNS number | S31603 |
| Material family | Austenitic stainless |
| Product specifications | A182 F316L, A403 WP316L, A312 TP316L |
| Density (typical) | 7.98 g/cm³ (7980 kg/m³) |
| Weight of 6" Sch 40 pipe | 28.73 kg/m |
Specifications by product form
One alloy is ordered under different ASTM/ASME numbers depending on form: forged flanges and fittings, wrought buttweld fittings, and pipe or tube. For Stainless 316L the usual specifications are A182 F316L, A403 WP316L, A312 TP316L. Quote both the specification and the UNS number on purchase orders to avoid ambiguity.
Chemical and mechanical limits differ between these specifications — always check the edition of the standard named on your order and the mill test certificate.
Chemical composition & mechanical properties
| Property | SS 316L |
|---|---|
| Family | Austenitic stainless |
| UNS | S31603 |
| EN / W.Nr | 1.4404 X2CrNiMo17-12-2 |
| Basis spec | ASTM A240 |
| Density g/cm³ | 7.98 |
| Chemical composition, % | |
| 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 |
| Mechanical properties (min) | |
| Tensile strength | 485 MPa (70 ksi) |
| Yield strength (0.2%) | 170 MPa (25 ksi) |
| Elongation | 40% |
| Hardness (max) | 217 HB |
| PREN (min, from spec) | 22.6 |
Single values are maximums; ranges are min–max; "bal" = balance. Limits are typical of the basis specification for that product form — forgings, pipe and fittings specifications differ slightly. Always check the exact specification, edition and the mill test certificate.
Frequently asked questions
What is the UNS number of Stainless 316L?
S31603.
Which ASTM specifications cover Stainless 316L?
A182 F316L, A403 WP316L, A312 TP316L.
What is the density of Stainless 316L?
About 7.98 g/cm³ (7980 kg/m³), used for weight calculations.
Last updated 2026-11-02