Stainless Steel 1.4740
EN 1.4740
1.4740 (GX40CrSi17) is a 17% Cr, high-silicon cast ferritic stainless steel supplied annealed, as-cast or stress relieved.
Reference datasheet — 1.4740 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 A condition
1.4740 tempers and conditions
1.4740 is supplied in 3 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard delivery condition for EN 10295 heat-resistant castings — lowest hardness, best machinability before service. | 280 | 500 | 8 | 22 HRC | 2.2 % IACS |
Stress relieved | Used after heavy machining, weld repair or on complex thin/thick-section castings to remove residual stress without full softening. | 290 | 520 | 6 | 24 HRC | 2.2 % IACS |
Spheroidize annealed | Cheapest route for rough furnace hardware that will be heat-cycled in service anyway; harder and more brittle than annealed. | 310 | 550 | 4 | 26 HRC | 2.2 % IACS |
What is 1.4740?
1.4740 (GX40CrSi17) is a 17% Cr, high-silicon cast ferritic stainless steel supplied annealed, as-cast or stress relieved. The higher chromium content raises scaling resistance to about 950 °C, above the 850 °C limit of 1.4729, so it is cast into turbocharger housings, exhaust manifolds and combustion equipment parts. Mechanical properties are modest — 280 MPa yield, 500 MPa tensile, 8% elongation at roughly 240 HB — and both machinability (32) and weldability are poor, so parts are designed to be cast close to net shape. Where 850 °C service is sufficient, 1.4729 is the usual lower-alloy choice. 1.4740 has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,400°C (2,552 °F). 1.4740 has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).
What is 1.4740 used for?
- turbocharger housings
- exhaust manifolds
- high-temperature valve components
- combustion equipment parts
Advantages
- High service temperature — 950°C (1,742 °F), better than 86% of stainless steel grades
- Low embodied carbon — 3.6 kg CO₂/kg, better than 83% of stainless steel grades
- Conducts heat well — 22 W/m·K (12.7 BTU/hr·ft·°F), better than 77% of stainless steel grades
Limitations
- Limited ductility — 8%, worse than 99% of stainless steel grades
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 99% of stainless steel grades
- Limited formability — 5/100, worse than 99% of stainless steel grades
- Hard to polish — 50/100, worse than 93% of stainless steel grades
- Difficult to weld — 25/100, worse than 92% of stainless steel grades
1.4740 properties
Typical room-temperature values for 1.4740-A; bars are the position among stainless steel grades.
Physical3
1.4740 has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical17
1.4740 has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4740 is rated for continuous service to 950°C (1,742 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), better than 77% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4740 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), worse than 76% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4740 takes about 50 MJ of energy and emits 3.6 kg of CO₂ — less than 80% of stainless steel grades. Typical recycled content is 80%.
Manufacturability7
1.4740's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability poor (25/100); formability not recommended (5/100).
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. 1.4740 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4740
Is 1.4740 easy to machine?
Machine in the soft-annealed state with rigid setups, sharp carbide tooling, low speed and heavy positive feed; the Cr carbides are abrasive and the material work-hardens if rubbed.
Can 1.4740 be welded?
Only fair — preheat 200–300 °C, use matching or 25Cr-type/Ni-base filler, keep interpass warm and follow with an 800–850 °C anneal to restore what ductility the grade has.
Can 1.4740 be formed, bent or molded?
Casting-only grade: good fluidity from the high Si, but design generous fillets, use feeders on heavy sections and avoid abrupt section changes because of hot-tearing and low as-cast ductility.
1.4740 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 |
|---|---|---|
| C | 0.3 – 0.5 | 0.4 |
| Sikey scaling-resistance addition | 1 – 2.5 | 1.8 |
| Mn | ≤ 1 | 0.6 |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Cr | 16 – 19 | 17.5 |
| Niresidual | ≤ 1 | |
| Moresidual, unless agreed | ≤ 0.5 | |
| Fe | balance |
What surface finishes work on 1.4740?
Shot-blast and pickle/passivate for a clean scale-free surface; the natural Cr-Si oxide formed in service is protective, so painting is unnecessary and polishing is limited by the cast carbide structure.
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 1.4740 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- GX40CrSi17
How much does 1.4740 cost?
1.4740 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.
1.4740 — frequently asked
What is 1.4740 used for?
1.4740 is typically used for turbocharger housings, exhaust manifolds, high-temperature valve components and combustion equipment parts. In short: highest-temperature cast Cr-Si; 950 °C scaling resistance; casting-only, poor machinability.
What is the yield strength of 1.4740?
1.4740 has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 75% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.4740 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Machine in the soft-annealed state with rigid setups, sharp carbide tooling, low speed and heavy positive feed; the Cr carbides are abrasive and the material work-hardens if rubbed.
Can 1.4740 be welded?
Not readily — weldability is rated poor (25/100). Only fair — preheat 200–300 °C, use matching or 25Cr-type/Ni-base filler, keep interpass warm and follow with an 800–850 °C anneal to restore what ductility the grade has.
What surface finishes work on 1.4740?
Shot-blast and pickle/passivate for a clean scale-free surface; the natural Cr-Si oxide formed in service is protective, so painting is unnecessary and polishing is limited by the cast carbide structure.
Can 1.4740 be formed, bent or molded?
Casting-only grade: good fluidity from the high Si, but design generous fillets, use feeders on heavy sections and avoid abrupt section changes because of hot-tearing and low as-cast ductility.
What is the maximum service temperature of 1.4740?
1.4740 is rated for continuous use to about 950°C (1,742 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4740-A and 1.4740-AC?
A is the default condition — standard delivery condition for EN 10295 heat-resistant castings — lowest hardness, best machinability before service. AC: cheapest route for rough furnace hardware that will be heat-cycled in service anyway; harder and more brittle than annealed. Yield strength is 280 MPa in A versus 310 MPa in AC.
How much does 1.4740 cost?
1.4740 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 10295 — Heat resistant steel castings — CEN (2002)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Casting Handbook (heat-resistant alloys section) — Steel Founders' Society of America (1995)
- Heat-resistant cast steel grade sheets (GX40CrSi13/17/24/28) — European heat-resistant casting foundries (2022)
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.