316L Stainless Steel (UNS S31603)
316 with carbon held to 0.030 percent for welded and heated service in chloride environments — the standard grade for pharmaceutical, chemical and offshore skids.
What 316L Stainless is.
Type 316L is 316 with the carbon limited to 0.030 percent, which prevents sensitization at welds and in service between 800 and 1500 °F. The annealed strength minimum drops slightly to 70 ksi, but most bar is dual certified 316/316L and meets both. It is the default austenitic grade on many refinery, pharmaceutical and offshore material lists.
We machine 316L bolts, studs, nuts and components from dual-certified A276 bar, supplied to F593 Group 2 conditions, and to A193 B8M when the order is pressure bolting.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon | C | — | 0.030 |
| Manganese | Mn | — | 2.00 |
| Phosphorus | P | — | 0.045 |
| Sulfur | S | — | 0.030 |
| Silicon | Si | — | 1.00 |
| Chromium | Cr | 16.0 | 18.0 |
| Nickel | Ni | 10.0 | 14.0 |
| Molybdenum | Mo | 2.00 | 3.00 |
Values per ASTM A276/A276M-17 Tables 1 and 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Mechanical properties.
| Condition and nominal diameter (in.) | Tensile strength, min (ksi) | Yield strength 0.2% offset, min (ksi) | Elongation, min (%) | Reduction of area, min (%) | Hardness |
|---|---|---|---|---|---|
| Condition A (annealed), hot finished — all | 70 | 25 | 40 | 50 | — |
| Condition A, cold finished — ½ and under | 90 | 45 | 30 | 40 | — |
| Condition A, cold finished — over ½ | 70 | 25 | 30 | 40 | — |
| Condition B (cold worked) — ¾ and under | 125 | 100 | 12 | 35 | — |
| Condition B — over ¾ to 1 | 115 | 80 | 15 | 35 | — |
| Condition B — over 1 to 1¼ | 105 | 65 | 20 | 35 | — |
| Condition B — over 1¼ to 1½ | 100 | 50 | 24 | 45 | — |
| Condition B — over 1½ to 1¾ | 95 | 45 | 28 | 45 | — |
| Condition S (strain hardened) — 2 and under | 95 | 75 | 25 | 40 | — |
| Condition S — over 2 to 2½ | 90 | 65 | 30 | 40 | — |
| Condition S — over 2½ to 3 | 80 | 55 | 30 | 40 | — |
Values per ASTM A276/A276M-17 Tables 1 and 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. Condition B and S limits are shared with 304 and 316.
| F593 condition · marking | Nominal diameter (in.) | Tensile strength (ksi) | Yield strength, min (ksi) | Rockwell hardness |
|---|---|---|---|---|
| AF (annealed after forming) · F593E | ¼ to 1½ | 65 to 85 | 20 | B85 max |
| A (annealed) · F593F | ¼ to 1½ | 75 to 100 | 30 | B65 to B95 |
| CW1 (cold worked) · F593G | ¼ to ⅝ | 100 to 150 | 65 | B95 to C32 |
| CW2 (cold worked) · F593H | ¾ to 1½ | 85 to 140 | 45 | B80 to C32 |
| SH1 (strain hardened) · F593E | ¼ to ⅝ | 120 to 160 | 95 | C24 to C36 |
| SH2 (strain hardened) · F593F | ¾ to 1 | 110 to 150 | 75 | C20 to C32 |
| SH3 (strain hardened) · F593G | 1⅛ to 1¼ | 100 to 140 | 60 | B95 to C30 |
| SH4 (strain hardened) · F593H | 1⅜ to 1½ | 95 to 130 | 45 | B90 to C28 |
Values per ASTM F593-24 Table 2, full-size tests (verified against the specification). Yield is 0.2 % offset; hardness is Rockwell. Machined-specimen limits differ slightly.
Specifications that apply.
How 316L Stainless ships from Houston.
- Hex and heavy hex bolts and cap screws
- Full-thread studs and threaded rod
- Socket head cap and set screws
- Hex, jam and lock nuts
- Washers and spacers
- Machined components from certified bar
316L Stainless fasteners we make.
Every item is manufactured to your drawing or standard in 316L Stainless, imperial or metric, with an EN 10204 3.1 certificate.
What is 316L stainless steel?
316L is the low-carbon version of 316. The molybdenum gives it the chloride resistance of 316 and the carbon limit gives it immunity to weld sensitization, so it is the grade for welded equipment in corrosive service. Strength in the annealed bar is a few ksi lower than 316, which rarely matters because dual-certified bar meets both, and cold-worked fastener conditions are identical.
When to specify 316L
- Welded assemblies and fasteners that are welded or tack welded in place.
- Service that dwells between 800 and 1500 °F.
- Any material list that calls for L grades, which is most pharmaceutical, refining and offshore specifications.
- For strength, order 316 Condition B or B8M Class 2; for more chloride resistance, step up to 254 SMO or duplex.
Testing, certification and marking
- Tensile and hardness tested per lot on the finished product
- Grade or marking symbol F593E to F593H and manufacturer's identification on every piece
- EN 10204 3.1 material test report with heat number and chemistry; 3.2 witness available
- PMI verification and intergranular corrosion testing (ASTM A262) arranged on request
316 Stainless Steel (UNS S31600)
The marine and chemical-plant stainless: 2 to 3 percent molybdenum for pitting and crevice resistance in chlorides, with the same strength tables as 304.
ASTM A276 bar · ASTM F593 bolts304L Stainless Steel (UNS S30403)
304 with carbon held to 0.030 percent so welds and heat-affected zones do not sensitize — the choice for welded assemblies and parts that will be heated in service.
ASTM A193 / ASME SA-193ASTM A193 Grade B8M Class 1 (316 Stainless)
316 stainless bolting with molybdenum for chloride and pitting resistance — offshore, marine, chemical and coastal plant fasteners.