Stainless Steel 1.4347
EN 1.4347
1.4347 (GX4CrNiN26-7, UNS S32900) is a molybdenum-free lean duplex casting alloy with 26Cr-7Ni and nitrogen, combining ferritic and austenitic phases for high strength and good chloride stress-corrosion resistance.
Reference datasheet — 1.4347 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 +AT condition
1.4347 tempers and conditions
1.4347 is supplied in 4 conditions, soft to hard. +AT is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Only for non-critical, non-corrosive parts — unbalanced phase ratio and Cr-nitride precipitation cut toughness and pitting resistance. | 450 | 650 | 14 | 22 HRC | 2.1 % IACS |
As-welded deposit | Condition of production weld repairs made with 25Cr-N over-alloyed filler; properties reflect HAZ nitride formation, re-solution treatment preferred. | 460 | 670 | 18 | 21 HRC | 2.2 % IACS |
+ATDefault Solution annealed | Standard delivery condition of EN 10283 castings — balanced 50/50 ferrite/austenite, maximum corrosion resistance and toughness. | 480 | 690 | 26 | 20 HRC | 2.2 % IACS |
hot isostatically pressed then solution annealed and quenched | Choose for pressure-containing or fatigue-critical castings where shrinkage porosity must be eliminated. | 500 | 720 | 30 | 20 HRC | 2.2 % IACS |
What is 1.4347?
1.4347 (GX4CrNiN26-7, UNS S32900) is a molybdenum-free lean duplex casting alloy with 26Cr-7Ni and nitrogen, combining ferritic and austenitic phases for high strength and good chloride stress-corrosion resistance. Solution-treated castings give 480 MPa yield, 690 MPa tensile, 26 % elongation and 225 HB, roughly double the yield of cast CF8 at similar cost. Service is capped at 300 °C because of 475 °C embrittlement, and the absence of molybdenum keeps pitting resistance moderate (score 65) — use cast super duplex 1.4417 for seawater and high-chloride duty. 1.4347 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). 1.4347 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
What is 1.4347 used for?
- structural castings
- valve bodies
- heat exchanger components
Advantages
- High strength — 480 MPa (69.6 ksi), better than 75% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
- Low fracture toughness — 90 MPa·√m (81.9 ksi·√in), worse than 75% of stainless steel grades
1.4347 properties
Typical room-temperature values for 1.4347-+AT; bars are the position among stainless steel grades.
Physical3
1.4347 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).
Mechanical17
1.4347 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4347 is rated for continuous service to 300°C (572 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), better than 58% of stainless steel grades. Thermal expansion is 12.8 µm/m·K (7.11 µin/in·°F).
Electrical3
1.4347 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 56% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4347 takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 65%.
Manufacturability8
1.4347's machinability is fair (35/100, better than 51% of stainless steel grades); weldability good (55/100); formability poor (25/100).
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. 1.4347 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4347
Is 1.4347 easy to machine?
Machine like duplex: rigid setup, sharp coated carbide, 25–40 % lower cutting speed than CF8M, heavy positive feed to cut under the work-hardened skin, ample coolant.
Can 1.4347 be welded?
Weldable with over-alloyed 25Cr-N (or 2209-type) filler; keep interpass below ~150 °C, moderate heat input for phase balance, no post-weld stress relief in the 550–950 °C range — re-solution treat critical parts.
Can 1.4347 be formed, bent or molded?
Sand or investment cast; use generous risering and chills for the narrow freezing range, then always solution treat at 1050–1100 °C with fast water quench to dissolve nitrides.
1.4347 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 |
|---|---|---|
| CGX4 = 0.04 % nominal | ≤ 0.06 | 0.04 |
| Si | ≤ 1 | 0.6 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Cr | 25 – 27 | 26 |
| Ni | 6 – 8 | 7 |
| Naustenite stabiliser, raises strength and pitting resistance | 0.12 – 0.22 | 0.16 |
| Moresidual only — grade is nominally Mo-free | ≤ 0.5 | |
| Fe | balance |
What surface finishes work on 1.4347?
Grit-blast, pickle in HNO₃/HF and passivate for full corrosion performance; polishes reasonably but the two-phase structure etches unevenly — no anodizing (ferrous).
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 1.4347 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- GX4CrNiN26-7
- Similar grades
- S32900
How much does 1.4347 cost?
1.4347 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.
1.4347 — frequently asked
What is 1.4347 used for?
1.4347 is typically used for structural castings, valve bodies and heat exchanger components. In short: mo-free lean duplex; 480 MPa cast yield; good chloride SCC resistance.
What is the yield strength of 1.4347?
1.4347 has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 75% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4347 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine like duplex: rigid setup, sharp coated carbide, 25–40 % lower cutting speed than CF8M, heavy positive feed to cut under the work-hardened skin, ample coolant.
Can 1.4347 be welded?
Yes — weldability is rated good (55/100). Weldable with over-alloyed 25Cr-N (or 2209-type) filler; keep interpass below ~150 °C, moderate heat input for phase balance, no post-weld stress relief in the 550–950 °C range — re-solution treat critical parts.
What surface finishes work on 1.4347?
Grit-blast, pickle in HNO₃/HF and passivate for full corrosion performance; polishes reasonably but the two-phase structure etches unevenly — no anodizing (ferrous).
Can 1.4347 be formed, bent or molded?
Sand or investment cast; use generous risering and chills for the narrow freezing range, then always solution treat at 1050–1100 °C with fast water quench to dissolve nitrides.
What is the maximum service temperature of 1.4347?
1.4347 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4347 +AT and 1.4347-F?
+AT is the default condition — standard delivery condition of EN 10283 castings — balanced 50/50 ferrite/austenite, maximum corrosion resistance and toughness. F: only for non-critical, non-corrosive parts — unbalanced phase ratio and Cr-nitride precipitation cut toughness and pitting resistance. Yield strength is 480 MPa in +AT versus 450 MPa in F.
How much does 1.4347 cost?
1.4347 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
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Practical Guidelines for the Fabrication of Duplex Stainless Steels — IMOA (2014)
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.