316 / 316L stainless steel: standards, composition and properties
316, 316L, 316H, 316Ti, 316LN and 316LVM · UNS S31600, S31603, S31609, S31635, S31653 · F316L, CF8M, CF3M, 1.4404
316 is the Cr-Ni austenitic stainless steel with 2 to 3 % molybdenum, which gives it resistance to chlorides and reducing acids far superior to 304. The same composition gets different names depending on the product form: TP316L for pipe, F316L for forgings, WP316L for fittings, CF3M when cast and 1.4404 in the European standard. The L, H, Ti, N/LN and LVM variants change carbon, nitrogen, titanium or cleanliness to suit welding, high temperature, strength or surgical implants.
UNSS31600 (316), S31603 (316L), S31609 (316H), S31635 (316Ti), S31651 (316N), S31653 (316LN), S31673 (316LVM)
CastCF8M (J92900) and CF3M (J92800), ASTM A351 / A743 / A744
EN / W.Nr.1.4401, 1.4404, 1.4571, 1.4435, 1.4436, 1.4429; cast 1.4408 / 1.4409; implant 1.4441
Base chemistry16–18 Cr, 10–14 Ni, 2–3 Mo, C ≤ 0.08 (L ≤ 0.030)
Typical PREN≈ 25 (316/316L); ≈ 26 (1.4435 / 316LVM)
One composition, several standards
The name changes with the product form. When specifying, cite the standard, grade and class.
| Form | ASTM/ASME | Grade/class | EN | ABNT/others |
|---|---|---|---|---|
| Plate, coil, strip | A240 / SA-240 | 316, 316L, 316H, 316Ti, 316N, 316LN | EN 10088-2; EN 10028-7 (pressure): 1.4401, 1.4404, 1.4571, 1.4435, 1.4429 | NBR 5601 (316, 316L, 316Ti*); AMS 5524 (316), AMS 5507 (316L); JIS G4304/G4305 SUS316/316L |
| Bar and section | A276 (general), A479 / SA-479 (pressure vessels) | 316, 316L, 316H, 316Ti, 316N, 316LN | EN 10088-3; EN 10272 (pressure) | AMS 5648 (316), AMS 5653 (316L); JIS G4303 SUS316/316L |
| Forging and flange | A182 / SA-182; A336 (heavy forgings); A965 (high temperature) | F316, F316L, F316H, F316Ti, F316N, F316LN | EN 10222-5: 1.4401, 1.4404, 1.4571, 1.4429 | ASME B16.5 flanges: group 2.2 (316, 316H, CF8M, CF3M) and 2.3 (316L) |
| Seamless and welded pipe | A312 / SA-312; A358 (welded, large diameter); A376 (high temperature) | TP316, TP316L, TP316H, TP316Ti, TP316N, TP316LN | EN 10216-5 (seamless), EN 10217-7 (welded) | AMS 5573 (seamless 316 tubing); JIS G3459 SUS316TP |
| Heat exchanger and boiler tube | A213 / SA-213 (seamless), A249 / SA-249 (welded), A269 (general), A270 (sanitary) | TP316, TP316L, TP316H, TP316Ti | EN 10216-5, EN 10217-7 | JIS G3463 SUS316TB |
| Welding fittings | A403 / SA-403 (butt-weld), A182 (forged socket/threaded) | WP316, WP316L, WP316H, WP316LN | EN 10253-4 | MSS SP-43 (light) |
| Casting | A351 / SA-351 (pressure), A743 (general), A744 (corrosion) | CF8M (≈316), CF3M (≈316L), CF3MN (≈316LN) | EN 10213: 1.4408 (GX5CrNiMo19-11-2), 1.4409 (GX2CrNiMo19-11-2) | JIS G5121 SCS14A / SCS16A |
| Surgical implant | ASTM F138 (bar, wire), F139 (sheet, strip) | 316LVM (UNS S31673) | ISO 5832-1; 1.4441 (X2CrNiMo18-15-3) | ABNT NBR ISO 5832-1 |
| Welding consumable | AWS A5.9 (wire), A5.4 (covered electrode) | ER316L, ER316LSi, ER316H, E316L-16, ER318* | EN ISO 14343: 19 12 3 L (Si) | — |
EN 1.4401/1.4404 require Mo 2.00–2.50 % (ASTM accepts 2.00–3.00 %); to guarantee Mo ≥ 2.5 % under the European standard, specify 1.4435 or 1.4436.
Tolerances and HS codes
- Forged bars (round and square): machining allowance from 2 mm (Ø 6–16 mm) to 24 mm (Ø 400–500 mm) on the diameter. E.g. Ø 100–125 mm finished: +7 mm, tolerance +6 / −0 (length up to 3,500 mm).
- Forged discs: allowance of 4 to 9 mm on the diameter and 3 to 11 mm on the height, plus-only tolerance.
- Cutting and machining: band saw −0 / +5 to +15 mm on length; waterjet +10 % of thickness on the diameter (min. 2 mm); machined parts −0 / +2 to +5 mm on the diameter. See the full tables (INF 002 and INF 003, the same for every alloy).
| Form | NCM (Brazil, 8 digits) | HS (international, 6 digits) | HTS (USA, 10 digits)* | CN (European Union, 8 digits)* |
|---|---|---|---|---|
| Forged bar | 7222.30.00* | 7222.30 | 7222.30.0024 | 7222 30 51 |
| Hot-rolled bar | 7222.11.00 | 7222.11 | 7222.11.0059 | 7222 11 11 |
| Plate (> 10 mm, width ≥ 600 mm) | 7219.21.00 | 7219.21 | 7219.21.0020 | 7219 21 10 |
| Seamless pipe | 7304.41.90 | 7304.41 | 7304.41.6045 | 7304 41 00 |
| Welded pipe | 7306.40.00 | 7306.40 | 7306.40.5085 | 7306 40 80 |
| Flange and fitting | 7307.21.00 | 7307.21 | 7307.21.5000 | 7307 21 00 |
Class in Dustre's NCM table (INF 004): stainless steel.
*: US and EU codes are for reference; confirm with your customs broker. NCM codes with * were checked by Dustre against the current NCM, outside the INF 004 table. HS = first 6 digits of the NCM.
Chemical composition by standard (%)
The ranges of each standard side by side, to see where they differ.
| Standard / grade | C | Mn | P max | S max | Si max | Cr | Ni | Mo | N | Others |
|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A240 316 (S31600) | 0.08 max | 2.00 max | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | 0.10 max | — |
| ASTM A240 316L (S31603) | 0.030 max | 2.00 max | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | 0.10 max | — |
| ASTM A240 316H (S31609) | 0.04–0.10 | 2.00 max | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | — | ASTM grain size No. 7 or coarser |
| ASTM A240 316Ti (S31635) | 0.08 max | 2.00 max | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | 0.10 max | Ti 5×(C+N) min, 0.70 max |
| ASTM A240 316LN (S31653) | 0.030 max | 2.00 max | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | 0.10–0.16 | 316N (S31651): same N with C 0.08 max |
| EN 10088-2 1.4404 (X2CrNiMo17-12-2) | 0.030 max | 2.00 max | 0.045 | 0.015 | 1.00 | 16.5–18.5 | 10.0–13.0 | 2.00–2.50 | 0.10 max | 1.4401: C 0.07 max; 1.4571: C 0.08, Ni 10.5–13.5, Ti 5×C to 0.70 |
| EN 10088-2 1.4435 (X2CrNiMo18-14-3) | 0.030 max | 2.00 max | 0.045 | 0.015 | 1.00 | 17.0–19.0 | 12.5–15.0 | 2.50–3.00 | 0.10 max | 1.4429 (316LN): N 0.12–0.22, Ni 11.0–14.0 |
| ASTM A351 CF8M (J92900) | 0.08 max | 1.50 max | 0.040 | 0.040 | 1.50 | 18.0–21.0 | 9.0–12.0 | 2.00–3.00 | — | CF3M (J92800): C 0.03 max, Cr 17.0–21.0, Ni 9.0–13.0 |
| ASTM F138 316LVM (S31673) | 0.030 max | 2.00 max | 0.025 | 0.010 | 0.75 | 17.00–19.00 | 13.00–15.00 | 2.25–3.00 | 0.10 max | Cu 0.50 max; Cr + 3.3 Mo ≥ 26.0 |
Mechanical properties by standard
Minimum values at room temperature, in the stated delivery condition.
| Standard and condition | YS min | UTS | Elong. | RA | Hardness |
|---|---|---|---|---|---|
| FORGINGS | |||||
| A182 F316 / F316H / F316Ti, solution annealed | 205 MPa (30 ksi) | 515 MPa min (75 ksi) | 30 % | 50 % (F316Ti: 40 %) | not specified |
| A182 F316L, solution annealed | 170 MPa (25 ksi) | 485 MPa min (70 ksi) | 30 % | 50 % | not specified |
| A182 F316LN, solution annealed | 205 MPa (30 ksi) | 515 MPa min (75 ksi) | 30 % | 50 % | not specified |
| A182 F316N, solution annealed | 240 MPa (35 ksi) | 550 MPa min (80 ksi) | 30 % | 50 % | not specified |
| ROLLED (PLATE AND BAR) | |||||
| A240 316 / 316H / 316Ti / 316LN, solution annealed | 205 MPa (30 ksi) | 515 MPa min (75 ksi) | 40 % | — | 217 HBW / 95 HRB max |
| A240 316L, solution annealed | 170 MPa (25 ksi) | 485 MPa min (70 ksi) | 40 % | — | 217 HBW / 95 HRB max |
| A240 316N, solution annealed | 240 MPa (35 ksi) | 550 MPa min (80 ksi) | 35 % | — | 217 HBW / 95 HRB max |
| A276 / A479 316, annealed | 205 MPa (30 ksi) | 515 MPa min (75 ksi) | 30 % (A479); 40 % (A276 hot rolled)* | 40 % (A479); 50 % (A276)* | — |
| EN 10088-2 1.4404, plate (P ≤ 75 mm) | 220 MPa | 520–670 MPa | 45 % | — | — |
| EN 10088-3 1.4404 / 1.4401, bar ≤ 160 mm | 200 MPa | 500–700 MPa | 40 % | — | — |
| ASTM F138 316LVM, annealed | 190 MPa | 490 MPa min | 40 % | — | — |
| ASTM F138 316LVM, cold worked | 690 MPa* | 860 MPa min* | 12 %* | — | — |
| PIPE, FITTINGS AND CASTINGS | |||||
| A312 TP316 / TP316H, solution annealed | 205 MPa (30 ksi) | 515 MPa min (75 ksi) | 35 % long. / 25 % transv. | — | — |
| A312 TP316L, solution annealed | 170 MPa (25 ksi) | 485 MPa min (70 ksi) | 35 % long. / 25 % transv. | — | — |
| A213 TP316 / TP316H / TP316Ti | 205 MPa (30 ksi) | 515 MPa min (75 ksi) | 35 % | — | 192 HBW / 90 HRB max |
| A213 TP316L | 170 MPa (25 ksi) | 485 MPa min (70 ksi) | 35 % | — | 192 HBW / 90 HRB max |
| A403 WP316 / WP316L | 205 / 170 MPa | 515 / 485 MPa min | 28 % long.* | — | — |
| A351 CF8M and CF3M, solution annealed | 205 MPa (30 ksi) | 485 MPa min (70 ksi) | 30 % | — | not specified |
316 vs. 316L vs. 316H vs. 316Ti: what changes is the carbon
316 has C up to 0.08 %; when welded or heated between ~425 and 815 °C it precipitates chromium carbides at the grain boundaries (sensitization) and loses resistance to intergranular corrosion. 316L (C ≤ 0.030 %) avoids this and is the standard for welded parts, but has a lower minimum YS (170 vs. 205 MPa). That is why mills sell plate and pipe dual-certified 316/316L: L chemistry with 316 strength. 316H (C 0.04–0.10 % and coarse grain) is the opposite: high carbon for creep strength above ~540 °C. 316Ti ties up the carbon with titanium and is the preferred European equivalent (1.4571), while 316LN adds nitrogen to recover the strength lost to the low carbon.
Heat treatments required by the standards
| Standard | Delivery condition | Temperature |
|---|---|---|
| ASTM A240, A479, A312, A213, A182 (316, 316L, 316N, 316LN) | Solution annealed and rapidly cooled (water or other fast medium) | ≥ 1040 °C (1900 °F) |
| ASTM A213 / A312 / A240 316H | Solution annealed, ASTM grain size No. 7 or coarser | ≥ 1040 °C (1900 °F) |
| ASTM 316Ti / EN 1.4571 | Solution annealed; optional stabilizing treatment by agreement | ≥ 1040 °C; stabilizing ≈ 870–900 °C* |
| EN 10088-2/-3 (1.4401, 1.4404, 1.4435, 1.4571) | Solution annealed (+AT), cooled in water or fast air | 1020–1120 °C* |
| ASTM A351 CF8M / CF3M | Solution annealed and water quenched | ≥ 1040 °C (1900 °F)* |
| ASTM F138 / ISO 5832-1 (316LVM) | Annealed, cold worked or extra hard (by condition) | per manufacturer |
Variants in the family
| Variant | Standards | Difference | YS / UTS |
|---|---|---|---|
| 316L (S31603, 1.4404) | A240, A182 F316L, A312 TP316L, A403 WP316L, CF3M | C ≤ 0.030 %: immune to sensitization in normal welding | 170 / 485 MPa (dual certified: 205 / 515) |
| 316H (S31609) | A240, A182 F316H, A312/A213 TP316H, A376 | C 0.04–0.10 % and coarse grain: creep above ~540 °C | 205 / 515 MPa |
| 316Ti (S31635, 1.4571) | A240, A182 F316Ti, A312 TP316Ti, EN 10088 | Ti 5×(C+N) to 0.70 % stabilizes the carbon | 205 / 515 MPa |
| 316N / 316LN (S31651 / S31653, 1.4429) | A240, A182 F316N/F316LN, A312 TP316LN, CF3MN | N 0.10–0.16 % (EN up to 0.22 %): more strength and austenite stability, cryogenic use | 316LN 205 / 515; 316N 240 / 550 MPa |
| 1.4435 (high Mo/Ni 316L) | EN 10088, BN2 / 316L UG (urea)* | Mo 2.5–3.0 %, Ni 12.5–15 %, minimal ferrite: pharmaceutical and urea | 220 / 520 MPa (plate) |
| 316LVM (S31673, 1.4441) | ASTM F138, F139, ISO 5832-1 | Vacuum remelted, Cr + 3.3 Mo ≥ 26, S ≤ 0.010, controlled inclusion cleanliness | 190 / 490 MPa annealed |
Corrosion, PREN and temperature
- PREN (Cr + 3.3 Mo + 16 N): ≈ 22.6 at the ASTM minimum and ≈ 25 typical for 316/316L; ≈ 26 for 1.4435 and 316LVM. Resists stagnant seawater only at low temperatures; for high chlorides use 904L, duplex or super austenitics.
- Chloride stress corrosion cracking: significant risk above ~60 °C with chlorides and tensile stress, as in every Cr-Ni austenitic.
- Sensitization: the ~425 to 815 °C range precipitates Cr carbides; prefer 316L or 316Ti in welded parts and check by ASTM A262 (practices A/E) or ISO 3651-2.
- Sigma phase: long exposure between ~550 and 900 °C forms sigma and reduces toughness; more critical in 316 with ferrite (welds, CF8M).
- Temperature: oxidation acceptable up to ~870 °C intermittent and ~925 °C continuous*; above ~540 °C use 316H (ASME only allows 316 stresses in that range with C ≥ 0.04 %*). Good toughness in cryogenic service.
- NACE MR0175/ISO 15156-3 and MR0103: accepted solution annealed, without cold work to increase strength, hardness ≤ 22 HRC (237 HBW), within the environmental limits of Table A.2 (≈ 60 °C and pH2S ≤ 100 kPa*).
Implant grade 316LVM (ASTM F138 / ISO 5832-1)
- Primary melting followed by vacuum arc remelting (VAR) or ESR for inclusion cleanliness, verified by ASTM E45*.
- Narrower chemistry than 316L: Cr 17–19, Ni 13–15, Mo 2.25–3.00, P ≤ 0.025, S ≤ 0.010, Cu ≤ 0.50 and Cr + 3.3 Mo ≥ 26.0.
- Fully austenitic microstructure, no delta ferrite, non-magnetic even after forming.
- Supplied annealed, cold worked or extra hard; strength rises from ~490 MPa (annealed) to more than 1000 MPa in cold-worked wire/small bar.
- Used in plates, bone screws, intramedullary nails, cerclage wire, stents and instruments; in Brazil, ABNT NBR ISO 5832-1.
Welding
| Item | Usual practice |
|---|---|
| 316 / 316L consumable | ER316L or ER316LSi (AWS A5.9), E316L-16 (A5.4); EN ISO 14343 19 12 3 L (Si) |
| 316H consumable | ER316H / E316H-16 (C 0.04–0.08 %) to keep creep strength |
| 316Ti consumable | ER316L or ER318 (Nb stabilized)*; Ti does not transfer well across the arc |
| Cast CF8M / CF3M | ER316 / ER316L; casting repair follows A351/A488 |
| Preheat | Not required |
| Interpass | ≤ 150 °C (common practice; some specifications accept 175 °C) |
| Ferrite in the weld metal | FN 3–10 to avoid hot cracking; low or none in cryogenic or urea service |
| PWHT | Not required; solution annealing only if required for corrosion. Dissimilar joint with carbon steel: ER309LMo |
Filler metal for welding
The wire composition is usually not identical to the material: each page explains why.
International equivalents
| System | Designation |
|---|---|
| AISI / SAE | 316, 316L, 316H, 316Ti, 316N, 316LN; SAE 30316 / 30316L |
| UNS | S31600, S31603, S31609, S31635, S31651, S31653, S31673; castings J92900 (CF8M), J92800 (CF3M) |
| EN / W.Nr. | 1.4401 X5CrNiMo17-12-2; 1.4404 X2CrNiMo17-12-2; 1.4436 X3CrNiMo17-13-3; 1.4435 X2CrNiMo18-14-3; 1.4571 X6CrNiMoTi17-12-2; 1.4429 X2CrNiMoN17-13-3; 1.4441 X2CrNiMo18-15-3; castings 1.4408 / 1.4409 |
| ABNT | NBR 5601: 316, 316L, 316N, 316Ti*; NBR ISO 5832-1 (implant) |
| JIS | SUS316, SUS316L, SUS316H*, SUS316Ti, SUS316N, SUS316LN; cast SCS14A (CF8M), SCS16A (CF3M) |
| GB (China) | 06Cr17Ni12Mo2 (316), 022Cr17Ni12Mo2 (316L), 07Cr17Ni12Mo2 (316H), 06Cr17Ni12Mo2Ti (316Ti), 022Cr17Ni12Mo2N (316LN)* |
| ISO / others | ISO 15510 X2CrNiMo17-12-2*; old AFNOR Z2CND17-12; BS 316S11 / 316S31* |
Equivalence is approximate: EN limits Mo to 2.00–2.50 % in 1.4401/1.4404 and S to 0.015 %, and the mechanical minimums differ; check the order standard before substituting.
Typical applications
| Form or industry | Where it is used |
|---|---|
| Chemicals and petrochemicals | Piping, vessels, exchangers and tanks for organic acids, dilute sulfuric acid and media with moderate chlorides |
| Oil and gas and offshore | Instrumentation tubing, fittings, F316L flanges, CF8M/CF3M valves, marine atmosphere |
| Food, beverage and pharmaceutical | A270 sanitary tubing, tanks, reactors; low-ferrite 1.4435 in purified water lines |
| Pulp and paper, water treatment | Bleaching, pumps, screens, effluent piping |
| High temperature and power | 316H in superheaters, headers and steam piping; 316Ti in exhausts and exchangers |
| Cryogenics | 316LN in tanks and components for liquefied gases and superconducting magnets |
| Medical | 316LVM in orthopedic implants, screws, stents and surgical instruments |
Frequently asked questions
Can I use 316L instead of 316?
Yes for corrosion, and it is preferred for welding. But the minimum YS of 316L is 170 MPa vs. 205 MPa; if the design was calculated with 316, order material dual-certified 316/316L.
What is the difference between F316L, TP316L, WP316L and CF3M?
It is the same alloy in different forms: F = forging (A182), TP = pipe/tube (A312/A213), WP = welding fitting (A403) and CF3M = casting (A351). The composition is almost the same; the casting has more Cr and Si and contains ferrite.
316Ti or 316L?
Both resist sensitization. 316L dominates the ASTM market; 316Ti (1.4571) is traditional in Europe and keeps a little more strength at temperature, but is harder to polish and to weld without Ti loss.
Is 316 magnetic?
Solution annealed it is practically non-magnetic. Cold work can form martensite and leave slight magnetism; welds and CF8M castings attract a little because of the ferrite. 316LVM is specified to remain non-magnetic.
Need 316 / 316L stainless?Bars, forgings and parts with EN 10204 3.1 certificate.
