Stainless Steel 1.3940
EN 1.3940
1.3940 (GX2CrNiN18-13, ASTM A743 CF3, UNS J92500) is a low-carbon 18Cr-13Ni austenitic stainless casting alloy, the European cast counterpart to 304L.
Reference datasheet — 1.3940 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SA condition
1.3940 tempers and conditions
1.3940 is supplied in 5 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard supply condition for all pressure-retaining and corrosion service — carbides dissolved, maximum corrosion resistance and ductility. | 250 | 530 | 55 | 140 HB | — |
As fabricated | Only for non-critical, non-corrosive structural castings; residual casting stresses and coarse dendritic structure lower ductility and toughness. | 250 | 500 | 35 | 150 HB | 2.3 % IACS |
Solution annealed + low-temperature impact tested | Pick for cryogenic valves, pumps and LNG service where documented sub-zero Charpy energy is required; ferrite content is normally capped for toughness. | 250 | 530 | 55 | 140 HB | 2.3 % IACS |
As-welded deposit | Permitted for this grade because C ≤0.03% prevents sensitization; use when re-solution-annealing a large casting is impractical. | 250 | 520 | 45 | 150 HB | 2.3 % IACS |
High-ferrite (controlled ferrite/Cr-Ni balance) higher-strength cast… | Same chemistry family but composition balanced to a higher δ-ferrite level for ~10% higher strength; avoid above ~350 °C because of 475 °C embrittlement. | 300 | 570 | 40 | 155 HB | 2.4 % IACS |
What is 1.3940?
1.3940 (GX2CrNiN18-13, ASTM A743 CF3, UNS J92500) is a low-carbon 18Cr-13Ni austenitic stainless casting alloy, the European cast counterpart to 304L. The ≤0.03 % carbon level limits carbide precipitation, so sand and investment castings can be welded and placed in corrosive service without a post-weld anneal; the default condition gives 250 MPa yield, 530 MPa tensile, 55 % elongation and 140 HB. Service is limited to about 425 °C and the alloy contains no molybdenum, so chloride pitting resistance is modest (corrosion score 63) — move to 1.3960 (CG3M) where pitting governs. 1.3940 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). 1.3940 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
What is 1.3940 used for?
- valve bodies
- pump casings
- food and chemical process fittings
Advantages
- Ductile — tolerates forming and impact — 55%, better than 97% of stainless steel grades
- Readily welded — 88/100, better than 91% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
Limitations
- Low strength — 250 MPa (36.3 ksi), worse than 91% of stainless steel grades
1.3940 properties
Typical room-temperature values for 1.3940-SA; bars are the position among stainless steel grades.
Physical3
1.3940 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical14
1.3940 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
1.3940 is rated for continuous service to 425°C (797 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.3940 conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (63/100), better than 53% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.3940 takes about 53 MJ of energy and emits 4.3 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
1.3940's machinability is fair (40/100, better than 72% of stainless steel grades); weldability excellent (88/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 1.3940 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.3940
Is 1.3940 easy to machine?
Gummy and work-hardening: use rigid setups, sharp positive-rake carbide, 60–110 m/min, heavy feed and flood coolant, avoid dwelling; watch for hard casting skin and sand inclusions.
Can 1.3940 be welded?
Excellent — GTAW/SMAW/FCAW with 308L (or 309L for dissimilar) filler; no post-weld anneal needed thanks to ≤0.03% C, keep interpass low and ferrite 3–10 FN to avoid hot cracking.
Can 1.3940 be formed, bent or molded?
Supplied as sand/investment castings; design generous fillets and directional feeding for the wide freezing range, and allow ~2% shrinkage plus machining stock.
1.3940 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cextra-low carbon, prevents sensitization | ≤ 0.03 | 0.02 |
| SiEN cast practice; ASTM CF3 allows up to 2.00 | ≤ 1.5 | 1 |
| MnASTM CF3 max 1.50 | ≤ 2 | 1 |
| P | ≤ 0.04 | |
| SASTM CF3 max 0.04 | ≤ 0.03 | |
| CrASTM CF3 range 17.0–21.0 | 17 – 20 | 18.5 |
| NiEN 18-13 balance; ASTM CF3 range 8.0–12.0 | 11 – 14 | 12.5 |
| Moresidual only | ≤ 0.5 | |
| Nnitrogen-alloyed EN designation GX2CrNiN18-13; ASTM CF3 has no N requirement | 0.1 – 0.2 | 0.15 |
| Fe | balance |
What surface finishes work on 1.3940?
Pickle/passivate (ASTM A967) or electropolish after grinding; shot blasting with iron-free media only. No anodizing; hard chrome or nitriding possible for wear faces.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 1.3940 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- GX2CrNiN18-13
- Similar grades
- A743 CF3J92500
How much does 1.3940 cost?
1.3940 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1.3940 — frequently asked
What is 1.3940 used for?
1.3940 is typically used for valve bodies, pump casings and food and chemical process fittings. In short: as-cast weldable 304L; no post-weld anneal; high 55 % elongation.
What is the yield strength of 1.3940?
1.3940 has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 91% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.3940 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Gummy and work-hardening: use rigid setups, sharp positive-rake carbide, 60–110 m/min, heavy feed and flood coolant, avoid dwelling; watch for hard casting skin and sand inclusions.
Can 1.3940 be welded?
Yes — weldability is rated excellent (88/100). Excellent — GTAW/SMAW/FCAW with 308L (or 309L for dissimilar) filler; no post-weld anneal needed thanks to ≤0.03% C, keep interpass low and ferrite 3–10 FN to avoid hot cracking.
What surface finishes work on 1.3940?
Pickle/passivate (ASTM A967) or electropolish after grinding; shot blasting with iron-free media only. No anodizing; hard chrome or nitriding possible for wear faces.
Can 1.3940 be formed, bent or molded?
Supplied as sand/investment castings; design generous fillets and directional feeding for the wide freezing range, and allow ~2% shrinkage plus machining stock.
What is the maximum service temperature of 1.3940?
1.3940 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.3940-SA and 1.3940-CF3A?
SA is the default condition — standard supply condition for all pressure-retaining and corrosion service — carbides dissolved, maximum corrosion resistance and ductility. CF3A: same chemistry family but composition balanced to a higher δ-ferrite level for ~10% higher strength; avoid above ~350 °C because of 475 °C embrittlement. Yield strength is 250 MPa in SA versus 300 MPa in CF3A.
How much does 1.3940 cost?
1.3940 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant (grade CF3, J92500) — ASTM International (2019)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM International (2018)
- EN 10213 — Steel castings for pressure purposes / EN 10283 corrosion-resistant steel castings — CEN (2016)
- ASM Specialty Handbook: Stainless Steels — Cast Stainless Steels — ASM International (1994)
- ASM Handbook Vol. 1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.