Stainless Steel 1.4458
EN 1.4458
1.4458 (GX2NiCrMo28-20-2, A744 CN7M, N08007) is a high-nickel, low-carbon cast stainless steel of the Alloy 20 type, with molybdenum and copper for strong sulfuric acid service.
Reference datasheet — 1.4458 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 ST condition
1.4458 tempers and conditions
1.4458 is supplied in 4 conditions, soft to hard. ST 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 |
|---|---|---|---|---|---|---|
STDefault Solution annealed | Standard delivery condition for all pressure and chemical-service castings; maximum corrosion resistance and ductility. | 235 | 490 | 42 | 140 HB | 1.6 % IACS |
Hot isostatically pressed then solution annealed | Specified for leak-tight, radiographed valve and pump castings where microporosity must be closed; toughness and fatigue improve. | 240 | 505 | 48 | 140 HB | 1.6 % IACS |
Spheroidize annealed | Only for non-critical, non-corrosive or rough-machining parts — interdendritic carbides/segregation cut corrosion resistance and toughness. | 250 | 470 | 28 | 150 HB | 1.6 % IACS |
Centrifugally cast tube/ring, solution annealed | Pick for pump sleeves, bushings and pipe spools: denser, finer structure than static castings gives slightly higher strength. | 255 | 520 | 40 | 145 HB | 1.6 % IACS |
What is 1.4458?
1.4458 (GX2NiCrMo28-20-2, A744 CN7M, N08007) is a high-nickel, low-carbon cast stainless steel of the Alloy 20 type, with molybdenum and copper for strong sulfuric acid service. Engineers specify it for pumps, valves and process castings in highly corrosive chemical duty; it is supplied solution treated as sand, investment or centrifugal castings, with HIP available. It is soft and ductile (235 MPa yield, 490 MPa tensile, 42 % elongation, 140 HB) rather than strong, machinability is low (score 30) and cost is well above CF8M. Rated to 500 °C; the closely related 1.4527 is the alternative where a higher Ni-Cu-Mo casting is specified. 1.4458 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,370°C (2,498 °F). 1.4458 has a yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 98% of stainless steel grades. Elongation at break is 42% and the elastic modulus is 193 GPa (28 Msi).
What is 1.4458 used for?
- sulfuric acid pumps and valves
- chemical processing castings
- fertilizer plant equipment
Advantages
- Good corrosion resistance — 79/100, better than 86% of stainless steel grades
Limitations
- Low electrical conductivity — 1.6 % IACS, worse than 99% of stainless steel grades
- Low strength — 235 MPa (34.1 ksi), worse than 98% of stainless steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades
- High embodied carbon — 5.8 kg CO₂/kg, worse than 86% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
1.4458 properties
Typical room-temperature values for 1.4458-ST; bars are the position among stainless steel grades.
Physical3
1.4458 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
1.4458 has a yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 98% of stainless steel grades. Elongation at break is 42% and the elastic modulus is 193 GPa (28 Msi).
Thermal5
1.4458 is rated for continuous service to 500°C (932 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades. Thermal expansion is 14.8 µm/m·K (8.22 µin/in·°F).
Electrical3
1.4458 conducts electricity at 1.6 % IACS, worse than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (79/100), better than 86% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4458 takes about 75 MJ of energy and emits 5.8 kg of CO₂ — more than 84% of stainless steel grades. Typical recycled content is 60%.
Manufacturability8
1.4458's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability good (65/100); formability poor (30/100).
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. 1.4458 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4458
Is 1.4458 easy to machine?
Gummy and rapidly work-hardening — rigid setup, positive-rake carbide, heavy constant feed, low speed (≈30–60 m/min) and copious coolant; avoid dwelling to prevent glazing.
Can 1.4458 be welded?
Readily welded by GTAW/SMAW with matching Nb-stabilized Alloy 20 filler (ER320LR / E320LR); use low heat input, stringer beads, interpass <150 °C, then re-solution anneal for the most aggressive acid service.
Can 1.4458 be formed, bent or molded?
Sand or investment cast with generous risering (wide freezing range, ~2.2 % shrink); no cold forming route — machine or weld-fabricate instead.
1.4458 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 |
|---|---|---|
| CASTM A744 CN7M ≤0.07; EN 1.4458 (GX2NiCrMo28-20-2) ≤0.03 | ≤ 0.07 | 0.03 |
| SiEN grade ≤1.0 | ≤ 1.5 | 0.8 |
| MnA744 CN7M ≤1.50 | ≤ 2 | 1 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.04 | 0.02 |
| Cr | 19 – 22 | 20.5 |
| NiA744 CN7M 27.5–30.5; EN 26–30 | 26 – 30.5 | 28.5 |
| MoEN grade 2.0–2.5 | 2 – 3 | 2.4 |
| CuA744 CN7M 3.0–4.0; EN 1.4458 lower Cu | 1.5 – 4 | 3 |
| Febalance, ≈43–47 % | balance |
What surface finishes work on 1.4458?
Grit blast, pickle in HNO₃–HF then passivate in nitric acid for full corrosion performance; not anodizable, electropolishing gives the best surface for acid service.
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 1.4458 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- GX2NiCrMo28-20-2
- Similar grades
- A744 CN7MN08007
How much does 1.4458 cost?
1.4458 is a high-cost stainless steel ($$$$), pricier than about 78% 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.
1.4458 — frequently asked
What is 1.4458 used for?
1.4458 is typically used for sulfuric acid pumps and valves, chemical processing castings and fertilizer plant equipment. In short: cast Alloy 20 equivalent; strong sulfuric acid resistance; very ductile cast stainless.
What is the yield strength of 1.4458?
1.4458 has a typical yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 98% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4458 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Gummy and rapidly work-hardening — rigid setup, positive-rake carbide, heavy constant feed, low speed (≈30–60 m/min) and copious coolant; avoid dwelling to prevent glazing.
Can 1.4458 be welded?
Yes — weldability is rated good (65/100). Readily welded by GTAW/SMAW with matching Nb-stabilized Alloy 20 filler (ER320LR / E320LR); use low heat input, stringer beads, interpass <150 °C, then re-solution anneal for the most aggressive acid service.
What surface finishes work on 1.4458?
Grit blast, pickle in HNO₃–HF then passivate in nitric acid for full corrosion performance; not anodizable, electropolishing gives the best surface for acid service.
Can 1.4458 be formed, bent or molded?
Sand or investment cast with generous risering (wide freezing range, ~2.2 % shrink); no cold forming route — machine or weld-fabricate instead.
What is the maximum service temperature of 1.4458?
1.4458 is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4458-ST and 1.4458 ST-CF?
ST is the default condition — standard delivery condition for all pressure and chemical-service castings; maximum corrosion resistance and ductility. ST-CF: pick for pump sleeves, bushings and pipe spools: denser, finer structure than static castings gives slightly higher strength. Yield strength is 235 MPa in ST versus 255 MPa in ST-CF.
How much does 1.4458 cost?
1.4458 is a high-cost stainless steel ($$$$), pricier than about 78% 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 A744/A744M — Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Severe Service (CN7M) — ASTM (2019)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM (2020)
- EN 10283 — Corrosion resistant steel castings (GX2NiCrMo28-20-2, 1.4458) — CEN (2010)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels; Cast Corrosion-Resistant Alloys — ASM International (1990)
- Alloy 20 (N08020/N08007) physical and corrosion data — Carpenter / Rolled Alloys (2021)
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.