Stainless Steel 1.4958
EN 1.4958 · UNS N08810 · also Incoloy 800H
1.4958 (X5NiCrAlTi31-20, N08810, Incoloy 800H) is the controlled-carbon, controlled-grain-size version of Alloy 800, solution annealed to a coarse grain that raises creep and stress-rupture strength for service to 1100 °C.
Reference datasheet — 1.4958 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
1.4958 tempers and conditions
1.4958 is supplied in 6 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged and solution annealed | Heavy forged sections for headers, flanges and pigtail fittings in reformer service; grain size controlled for creep design. | 215 | 510 | 40 | 145 HB | 1.7 % IACS |
SADefault Solution annealed | Standard supply condition for plate, tube and pipe used in creep-range service; gives the coarse grain required for 800H creep properties. | 220 | 520 | 45 | 140 HB | — |
Cold drawn then solution annealed bar/tube | Precision seamless tube and bright bar restored to full 800H creep condition after cold drawing. | 225 | 520 | 45 | 140 HB | 1.7 % IACS |
Hot rolled plate, solution annealed and pickled | Heavy plate for furnace retorts, headers and pressure parts; slightly higher strength than thin annealed product. | 240 | 540 | 42 | 150 HB | 1.7 % IACS |
Cold rolled sheet/strip, annealed | Thin gauge sheet and strip for furnace muffles, radiant tubes and formed components requiring a smooth surface. | 250 | 550 | 45 | 145 HB | 1.7 % IACS |
Cold drawn | Choose for close-tolerance bar and small-bore tubing where higher room-temperature strength and better surface finish are wanted; not for long-term creep service without re-anneal. | 400 | 620 | 30 | 11 HRC | 1.7 % IACS |
What is 1.4958?
1.4958 (X5NiCrAlTi31-20, N08810, Incoloy 800H) is the controlled-carbon, controlled-grain-size version of Alloy 800, solution annealed to a coarse grain that raises creep and stress-rupture strength for service to 1100 °C. It is specified for pressure-retaining high-temperature components and is supplied as solution-annealed plate, hot- and cold-rolled sheet, cold-drawn and annealed bar, and annealed forgings. Room-temperature properties are modest (220 MPa yield, 520 MPa tensile, 45 % elongation) and machinability is limited (score 30). Where the highest creep-rupture strength is needed, 1.4959 (800HT) with a controlled Al+Ti range is the next step up. 1.4958 has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,357°C (2,475 °F). 1.4958 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 99% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
What is 1.4958 used for?
- reformer tubes
- cracking furnace components
- heat exchanger tubing
- power generation piping
Advantages
- High service temperature — 1,100°C (2,012 °F), better than 96% of stainless steel grades
- Forms and bends easily — 72/100, better than 84% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Low strength — 220 MPa (31.9 ksi), worse than 99% of stainless steel grades
- Poor heat conductor — 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades
- High embodied carbon — 6.8 kg CO₂/kg, worse than 95% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
1.4958 properties
Typical room-temperature values for 1.4958-SA; bars are the position among stainless steel grades.
Physical3
1.4958 has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,357°C (2,475 °F).
Mechanical15
1.4958 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 99% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal5
1.4958 is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades. Thermal expansion is 14.4 µm/m·K (8 µin/in·°F).
Electrical3
1.4958 conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4958 takes about 90 MJ of energy and emits 6.8 kg of CO₂ — more than 94% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
1.4958's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (78/100); formability very good (72/100).
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. 1.4958 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4958
Is 1.4958 easy to machine?
Machine like a tough austenitic: rigid setup, positive-rake carbide, low speed / heavy positive feed, flood coolant and no dwelling — the alloy work-hardens rapidly and is gummy.
Can 1.4958 be welded?
Readily welded by GTAW/GMAW/SMAW with Ni-Cr-Nb fillers (ERNiCr-3 / ENiCrFe-2); no preheat needed, keep interpass low and heat input moderate, post-weld heat treatment normally unnecessary.
Can 1.4958 be formed, bent or molded?
Good cold formability but ~1.5× the forming loads of 304 and high springback; hot work at 950–1200 °C and re-solution anneal at 1100–1180 °C to restore the coarse grain required for 800H creep properties.
1.4958 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 |
|---|---|---|
| Ccontrolled carbon distinguishes 800H from 800 (EN 1.4958 permits 0.03–0.08) | 0.05 – 0.1 | 0.07 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1.5 | 0.8 |
| P | ≤ 0.03 | |
| S | ≤ 0.02 | |
| Cr | 19 – 23 | 21 |
| Ni | 30 – 35 | 32 |
| Al | 0.15 – 0.6 | 0.4 |
| Ti | 0.15 – 0.6 | 0.4 |
| Cu | ≤ 0.75 | |
| Febalance, 39.5 % min per ASTM B409/B408 | ≥ 39.5 (balance) |
What surface finishes work on 1.4958?
Pickle in HNO₃–HF or bright anneal to remove the tenacious Cr/Al/Ti oxide before service; can be ground and polished to a bright finish, not anodizable, plating rarely used.
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 1.4958 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08810
- EN / DIN / Werkstoff-Nr.
- X5NiCrAlTi31-20
- Trade names
- Incoloy 800H
How much does 1.4958 cost?
1.4958 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.
1.4958 — frequently asked
What is 1.4958 used for?
1.4958 is typically used for reformer tubes, cracking furnace components, heat exchanger tubing and power generation piping. In short: creep-rated Alloy 800; coarse-grain 800H condition; pressure service to 1100 °C.
What is the yield strength of 1.4958?
1.4958 has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 99% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1.4958 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Machine like a tough austenitic: rigid setup, positive-rake carbide, low speed / heavy positive feed, flood coolant and no dwelling — the alloy work-hardens rapidly and is gummy.
Can 1.4958 be welded?
Yes — weldability is rated very good (78/100). Readily welded by GTAW/GMAW/SMAW with Ni-Cr-Nb fillers (ERNiCr-3 / ENiCrFe-2); no preheat needed, keep interpass low and heat input moderate, post-weld heat treatment normally unnecessary.
What surface finishes work on 1.4958?
Pickle in HNO₃–HF or bright anneal to remove the tenacious Cr/Al/Ti oxide before service; can be ground and polished to a bright finish, not anodizable, plating rarely used.
Can 1.4958 be formed, bent or molded?
Good cold formability but ~1.5× the forming loads of 304 and high springback; hot work at 950–1200 °C and re-solution anneal at 1100–1180 °C to restore the coarse grain required for 800H creep properties.
What is the maximum service temperature of 1.4958?
1.4958 is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4958-SA and 1.4958-CD?
SA is the default condition — standard supply condition for plate, tube and pipe used in creep-range service; gives the coarse grain required for 800H creep properties. CD: choose for close-tolerance bar and small-bore tubing where higher room-temperature strength and better surface finish are wanted; not for long-term creep service without re-anneal. Yield strength is 220 MPa in SA versus 400 MPa in CD.
How much does 1.4958 cost?
1.4958 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 B409 / B408 / B564 — Ni-Fe-Cr alloy plate, bar and forgings (UNS N08810) — ASTM International (2021)
- EN 10095 — Heat resisting steels and nickel alloys (X5NiCrAlTi31-20, 1.4958) — CEN (1999)
- INCOLOY alloy 800H & 800HT product datasheet — Special Metals Corporation (2004)
- ASM Handbook Vol. 1 — Heat-Resistant Alloys — ASM International (1990)
- ASME BPVC Section II Part D — allowable stresses for N08810 — ASME (2023)
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.