Last verified 19 August 2026.
The comparison
| Property | 316 | 316L | Evidence |
|---|---|---|---|
| Proof strength Rp0.2, minimum (EN) | 240 MPa | 240 MPa | E3 E3 |
| Tensile strength Rm, minimum | 530 MPa | 530 MPa | E3 E3 |
| Elongation A, minimum | 40 % | 40 % | E3 E3 |
| PREN | 24 — | 24 — | E3 E3 |
| Density | 8.0 g/cm³ | 8.0 g/cm³ | E3 E3 |
| Modulus of elasticity | 200 GPa | 200 GPa | E3 E3 |
| Thermal conductivity | 15 W/(m·K) | 15 W/(m·K) | E3 E3 |
| Proof strength Rp0.2, minimum | not established here | 170 MPa | — / E3 |
All shared rows compare like for like.
The trap on this comparison
Proof strength Rp0.2 is specified twice: 170 MPa (ASTM A240/A240M, plate, annealed, 20 °C) and 240 MPa (EN 10088-2, cold rolled coil and sheet, 20 °C) — 41% apart. Both correct. Which one governs is a question about your drawing and your product form, not about the material.
Where each side’s numbers come from
See 316 and 316L — each page lists every source, every demotion and every gap. Nothing on this page is derived from anything not on those two, and our coverage limits are stated separately.
Where a PREN appears above, read it as a ranking number rather than a qualification: what PREN can and cannot tell you.
When to choose which
316. Availability and price, when the part is not going to be welded into service or the section is thick enough that a sensitised heat-affected zone does not matter. Bar, machined components and fasteners are the usual home: they are often not welded, and the higher carbon gives slightly better machining behaviour than the L grade.
316L. It is the default molybdenum-bearing austenitic, and the reasons are practical rather than exceptional. Single phase, so no phase balance to manage in welding. Forgiving heat input. Formable. Stocked by everyone in every product form. Every fabricator has qualified procedures for it. When a design is not strength-driven and the environment is not aggressive, 316L is chosen because choosing anything else has to be justified.
Against 316: Welding, most of the time. Carbon above roughly 0.03% is enough to precipitate chromium carbides at grain boundaries as a weld cools, and the corrosion resistance of the heat-affected zone goes with it. Where a part is welded and will get wet, the L grade removes the question for almost no money. The other reason is chlorides — at PREN 24 this is a mid-table alloy, not a seawater one.
Against 316L: Two things. Strength: at the 170 MPa ASTM A240 plate minimum it is weak for a structural section, and a strength-driven part in 316L is thick. Chlorides: the molybdenum helps against pitting relative to 304, but 316L is marginal in warm chloride service, and the failure mode that usually appears is crevice corrosion at gaskets and joints, which PREN does not predict.
What this comparison does not cover
- The carbon limit, which is the only thing that distinguishes this grade from 316L, is not established here.
- The ASTM plate minima are not established here.
- Elevated and cryogenic temperature behaviour.
- Fatigue, fracture toughness and chloride stress corrosion cracking.
- Welding procedure guidance, filler selection and post-weld treatment.
- Whether 316 or 316L is right for your part. The page next door compares them; neither page decides it.
- Composition limits are not established, and they are what a purchase order actually specifies.
- Fatigue, fracture toughness and stress corrosion cracking.
- Product forms other than plate, where minima differ.
- Whether 316L suits your application. No page can answer that.
Generated from data/materials/316.yaml and 316l.yaml.