1.4404 steel (1.4404): properties, composition, equivalents
1.4404 (X2CrNiMo17-12-2) is the EN low-carbon 316L: 16.5–18.5 % Cr, 10–13 % Ni, 2–2.5 % Mo, ≤ 0.03 % C. 220 MPa yield, 520–670 MPa tensile, PREN ≈ 24. Composition, properties, 316L/SUS316L equivalents.
What is 1.4404?
1.4404 (X2CrNiMo17-12-2) is the European name for 316L: an austenitic stainless steel with 17 % Cr, 11 % Ni and 2–2.5 % molybdenum, carbon held to 0.03 % so that welded joints stay free of chromium-carbide sensitization. The Mo addition roughly triples the resistance to chloride pitting compared with 1.4301 (PREN 24 vs 18), which is why 1.4404 is the default grade for coastal architecture, chemical and pharmaceutical process equipment, swimming-pool fittings and marine hardware.
Mechanically it is close to 1.4301 — 220 MPa yield, 520–670 MPa tensile, 40 % elongation — and equally non-magnetic and cryogenic-tough. It is not hardenable by heat treatment; strength is raised only by cold work.
EN 10088 makes 1.4404 a subset of ASTM 316L (S31603): the EN Mo window (2.0–2.5 %) sits at the low end of ASTM's 2.0–3.0 %, so material certified 1.4404 automatically meets 316L, and most plate and coil is dual-certified 1.4404/316L. In German industry the group is called "V4A". The related grades — 1.4401 (316, higher carbon), 1.4571 (316Ti, titanium-stabilized) and 1.4432/1.4436 (higher Mo) — are cross-referenced below.
1.4404 chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.03 | |
| Si | ≤ 1 | |
| Mn | ≤ 2 | |
| P | ≤ 0.045 | |
| S | ≤ 0.015 | 0.030 for long products (EN 10088-3) |
| N | ≤ 0.1 | |
| Cr | 16.5 – 18.5 | |
| Mo | 2 – 2.5 | |
| Ni | 10 – 13 |
EN 10088-2:2014 Table 3. Compare ASTM 316L (S31603): Cr 16.0–18.0, Ni 10.0–14.0, Mo 2.00–3.00 — the ASTM Mo window is wider on the high side.
1.4404 mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| Cold-rolled strip/sheet (C), ≤ 8 mm, +AT | ≥ 240 (≥ 34.8) | 530–680 (76.9–98.6) | 40 | ≤ 215 HB |
| Hot-rolled strip (H), ≤ 13.5 mm, +AT | ≥ 220 (≥ 31.9) | 520–670 (75.4–97.2) | 40 | ≤ 215 HB |
| Hot-rolled plate (P), ≤ 75 mm, +AT | ≥ 220 (≥ 31.9) | 520–670 (75.4–97.2) | 40 | ≤ 215 HB |
| Bar ≤ 160 mm, +AT (EN 10088-3) | ≥ 200 (≥ 29.0) | 500–700 (72.5–101.5) | 40 | ≤ 215 HB |
| Rp1.0 (design) | ≥ 260 (P) / ≥ 270 (C) (≥ 37.7 (P) / ≥ 39.2 (C)) | — | — | — |
Solution annealed (+AT, 1030–1110 °C, quenched), +20 °C, transverse for flat products.
Impact toughness
1.4404 requires a minimum Charpy V-notch energy of 60 J at -196 °C (typical). Fully austenitic; used for cryogenic and LNG service down to −196 °C without transition.
1.4404 equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| 316L | AISI / SAE | Identical | UNS S31603 (ASTM A240): C ≤ 0.03, Cr 16–18, Ni 10–14, Mo 2–3; 1.4404 sits inside the 316L window and is dual-certified. |
| 316S11 | BS (superseded British) | Identical | BS 1449 316S11: C ≤ 0.03, Cr 16.5–18.5, Ni 10–13, Mo 2–2.5. |
| 022Cr17Ni12Mo2 | GB/T (China) | Identical | GB/T 20878 022Cr17Ni12Mo2 (formerly 00Cr17Ni14Mo2). |
| SUS316L | JIS (Japan) | Identical | JIS G4304 SUS316L: C ≤ 0.03, Cr 16–18, Ni 12–15, Mo 2–3. |
| 316 | AISI / SAE | Near | S31600 allows C ≤ 0.08; 1.4401 is the EN counterpart. 1.4404 meets 316 mechanicals only at the low end (316 requires Rp0.2 ≥ 205 MPa — satisfied). |
| 1.4401 | EN (European) | Near | X5CrNiMo17-12-2 (316): C ≤ 0.07; higher strength minimums (Rp0.2 ≥ 240 MPa plate). |
| 1.4571 | EN (European) | Near | X6CrNiMoTi17-12-2 (316Ti): Ti-stabilized instead of low-carbon; same corrosion class, slightly higher strength, poorer polish. |
| 1.4432 / 1.4436 | EN (European) | Near | 2.5–3.0 % Mo versions (316L high-Mo) for slightly higher PREN. |
| 03Kh17N14M3 | GOST (Russia/CIS) | Near | GOST 5632 03Kh17N14M3: C ≤ 0.03, Mo 2.5–3.0, Ni 13–15 — richer than 1.4404. |
| 1.4301 | EN (European) | Functional | Non-Mo 304: cheaper, lower pitting resistance. |
| 1.4462 | EN (European) | Functional | Austenitic 316L: half the yield strength, PREN 24; the grade 1.4462 usually replaces. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for 1.4404 →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| X2CrNiMo17 13 2 | DIN 17440 (withdrawn) | Same number 1.4404; name changed to 17-12-2 in EN 10088. |
| V4A | Krupp trade name | German colloquial name for the Mo-bearing austenitics (1.4401, 1.4404, 1.4571). |
| 316S11 | BS 1449 / BS 970 | |
| Z3CND17-12-02 | NF A 35-573 |
Product forms and tolerance standards
Product forms: cold-rolled sheet and coil (2B, 2R, brushed), hot-rolled plate, bar, wire, profiles (EN 10088-3), welded and seamless tube and pipe (EN 10217-7, EN 10216-5), fittings, flanges, fasteners (A4-70).
Dimensional tolerances: cold-rolled: EN ISO 9445-2; plate: EN 10029; bar: EN 10278 / EN 10060; tube: EN ISO 1127.
Key property values
1.4404 yield strength
Rp0.2 ≥ 220 MPa plate (32 ksi), ≥ 240 MPa cold-rolled sheet; Rp1.0 ≥ 260 MPa. EN 1993-1-4 design values: fy = 220 MPa (plate) / 240 MPa (cold-rolled).
1.4404 tensile strength
520–670 MPa (plate, 75–97 ksi), 530–680 MPa (cold-rolled). Bar 500–700 MPa.
1.4404 hardness
Max 215 HB annealed (≈ 95 HRB). Not heat-treatable; cold-worked strip up to 350–400 HV.
Corrosion resistance
PREN = Cr + 3.3 Mo + 16 N ≈ 23.5–25. Critical pitting temperature (6 % FeCl₃) ≈ 15–20 °C. Resistant to seawater splash, de-icing salts, dilute sulphuric and phosphoric acids, most organic acids; not resistant to hot concentrated chlorides (use 1.4462 duplex or 1.4539/904L).
Physical properties
Density 8.0 g/cm³, E = 200 GPa, expansion 16 × 10⁻⁶/K, conductivity 15 W/m·K, resistivity 0.75 Ω·mm²/m, non-magnetic (μr ≈ 1.005 annealed).
Heat treatment
Solution anneal 1030–1110 °C, water or forced-air quench. Because C ≤ 0.03 %, 1.4404 can be welded in any thickness without post-weld annealing for corrosion reasons.
Weldability
Excellent weldability by TIG, MIG, MMA, SAW and laser; filler 19 12 3 L / ER316L. No preheat; interpass ≤ 150 °C. Low carbon eliminates sensitization in the HAZ, so post-weld heat treatment is not required. Pickle or electropolish welds exposed to chlorides to restore the passive layer.
Machining, forming and heat treatment
Machinability index ≈ 40 % (slightly worse than 1.4301 because of Mo and work hardening). Forming, deep drawing and spinning are very good; spring-back is high. Finishes: 2B, 2R (BA), brushed (grit 240–320), electropolished for pharma and food contact.
Typical applications
- Chemical, pharmaceutical and food process vessels, piping and heat exchangers
- Coastal and urban architecture: facades, handrails, roofing
- Swimming-pool and spa fittings (with regular cleaning; 1.4462 for indoor pools)
- Marine hardware, deck fittings, boat rails
- Water treatment, desalination pre-treatment, brewery and dairy equipment
- Medical implants and instruments (as ASTM F138 1.4441 variant)
- Fasteners A4-70 / A4-80 (ISO 3506)
1.4404 compared with related grades
Frequently asked questions
Is 1.4404 the same as 316L?
Yes. 1.4404 (EN 10088) and 316L (UNS S31603, ASTM A240) are dual-certified; the EN Mo window (2.0–2.5 %) lies inside the ASTM window (2.0–3.0 %), so 1.4404 always satisfies 316L.
What is the difference between 1.4404 and 1.4401?
Carbon: 1.4404 ≤ 0.03 % (316L), 1.4401 ≤ 0.07 % (316). 1.4401 has slightly higher strength minimums (Rp0.2 ≥ 240 MPa plate) but can sensitize when welded in thick sections. Most suppliers stock 1.4401/1.4404 dual-certified.
1.4404 or 1.4571 — which is better?
Same corrosion class (PREN ≈ 24). 1.4571 (316Ti) has ~10 % higher strength and better creep resistance to 550 °C, but the titanium carbides leave streaks when polished. Choose 1.4404 for polished, hygienic and welded sheet; 1.4571 for hot-service and heavy plate in German-spec projects.
Is 1.4404 suitable for seawater?
For splash zones, boat fittings and intermittent exposure, yes with cleaning. For continuous immersion in warm seawater it will crevice-corrode; use 1.4462 (duplex), 1.4539 (904L) or 6 % Mo grades.
Is 1.4404 magnetic?
No when annealed. Heavy cold work induces a slight magnetic response, less than in 1.4301 because the higher Ni stabilizes the austenite.
Related grades
Verified against EN 10088-2:2014; EN 10088-2:2014 Tables 3 and 12; EN 10088-3:2014; ASTM A240/A240M-22 (comparison). Last checked: September 2026.