Nickel Alloy Incoloy 800H
UNS N08810 · EN 1.4958
Incoloy 800H (N08810, 1.4958) is the controlled-carbon, controlled-coarse-grain variant of Alloy 800, an iron-nickel-chromium solid-solution alloy tuned for creep and stress-rupture strength in high-temperature pressure parts.
Reference datasheet — Incoloy 800H 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
Incoloy 800H tempers and conditions
Incoloy 800H 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 |
|---|---|---|---|---|---|---|
SADefault Solution Annealed | Standard supply condition for ASME code high-temperature pressure parts, furnace tubing and plate. | 220 | 520 | 45 | 140 HB | — |
Forged and Annealed | Forged pressure components re-solutioned to restore the coarse ASTM 5 grain size required for creep credit. | 230 | 530 | 42 | 145 HB | 1.7 % IACS |
Hot-Finished and Annealed | Heavy plate, forged/hot-rolled bar and hot-finished tube; slightly higher strength than fully re-solutioned thin product. | 240 | 545 | 42 | 150 HB | 1.7 % IACS |
Cold-Drawn and Annealed | Choose for close-tolerance bright bar and small-diameter tubing that still needs code-annealed properties. | 255 | 560 | 42 | 160 HB | 1.7 % IACS |
As-welded deposit | Typical cross-weld properties of fabricated assemblies welded without post-weld solution treatment. | 300 | 540 | 35 | 165 HB | 1.7 % IACS |
Cold worked | Use only where higher room-temperature strength/hardness is needed and long-term high-temperature (creep) service is not required. | 620 | 760 | 15 | 21 HRC | 1.7 % IACS |
What is Incoloy 800H?
Incoloy 800H (N08810, 1.4958) is the controlled-carbon, controlled-coarse-grain variant of Alloy 800, an iron-nickel-chromium solid-solution alloy tuned for creep and stress-rupture strength in high-temperature pressure parts. It is used as reformer and cracker tubing, high-temperature vessels and furnace fixtures in tube, pipe, plate and bar. Annealed values are about 220 MPa yield, 520 MPa tensile, 45% elongation and 140 HB, with service to 1100 °C, weldability score 80 and corrosion resistance 76. Machinability is poor (score 30), and full creep credit depends on holding the coarse ASTM 5 grain size; 800HT tightens the C+N and grain-size window further. Incoloy 800H has a density of 7.94 g/cm³ (0.287 lb/in³), lighter than 88% of nickel alloy grades. It melts at 1,357°C (2,475 °F). Incoloy 800H has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 93% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
What is Incoloy 800H used for?
- reformer/cracker tubes
- high-temperature pressure vessels
- heat treating fixtures
Advantages
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 99% of nickel alloy grades
- Low embodied carbon — 9 kg CO₂/kg, better than 91% of nickel alloy grades
- Easy to machine — 30/100, better than 90% of nickel alloy grades
- High service temperature — 1,100°C (2,012 °F), better than 88% of nickel alloy grades
- High electrical conductivity — 1.7 % IACS, better than 80% of nickel alloy grades
Limitations
- Low strength — 220 MPa (31.9 ksi), worse than 93% of nickel alloy grades
Incoloy 800H properties
Typical room-temperature values for Incoloy 800H-SA; bars are the position among nickel alloy grades.
Physical3
Incoloy 800H has a density of 7.94 g/cm³ (0.287 lb/in³), lighter than 88% of nickel alloy grades. It melts at 1,357°C (2,475 °F).
Mechanical15
Incoloy 800H has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 93% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
Incoloy 800H 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), better than 57% of nickel alloy grades. Thermal expansion is 14.4 µm/m·K (8 µin/in·°F).
Electrical3
Incoloy 800H conducts electricity at 1.7 % IACS, better than 80% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (76/100), worse than 59% of nickel alloy grades.
Sustainability4
Producing a kilogram of Incoloy 800H takes about 105 MJ of energy and emits 9 kg of CO₂ — less than 94% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability7
Incoloy 800H's machinability is poor (30/100, better than 90% of nickel alloy grades); weldability very good (80/100); 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 nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Incoloy 800H is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Incoloy 800H
Is Incoloy 800H easy to machine?
Gummy and work-hardening — use rigid setups, positive-rake carbide, low speed (15–30 m/min) with heavy positive feed and copious sulphur-free coolant; never dwell in the cut.
Can Incoloy 800H be welded?
Readily welded by GTAW/GMAW/SMAW with ERNiCr-3 or ENiCrFe-2/-3 filler, low heat input, no preheat, interpass <150 °C; keep sulphur/lead contamination off the joint and re-solution treat if full creep credit is required.
Can Incoloy 800H be formed, bent or molded?
Excellent cold formability at ~2× the force of 304; hot work at 1150–900 °C and finish above 900 °C, then solution anneal at 1120–1180 °C and rapid cool to restore the coarse ASTM 5 grain size.
Incoloy 800H 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 |
|---|---|---|
| Ni | 30 – 35 | 32 |
| Cr | 19 – 23 | 21 |
| Ccontrolled carbon — key difference vs Alloy 800 | 0.05 – 0.1 | 0.08 |
| Al | 0.15 – 0.6 | 0.4 |
| Ti | 0.15 – 0.6 | 0.4 |
| Al+Ticombined limit | 0.3 – 1.2 | 0.8 |
| Mn | ≤ 1.5 | 0.8 |
| Si | ≤ 1 | 0.4 |
| Cu | ≤ 0.75 | 0.2 |
| S | ≤ 0.02 | 0 |
| Fe39.5 % min per ASTM B409 | ≥ 39.5 (balance) |
What surface finishes work on Incoloy 800H?
Pickle in HNO3-HF or grit blast plus passivation to remove green Cr-rich scale; not anodisable — protective service comes from the self-forming Cr2O3/spinel layer.
Surface treatments FabDigit runs on nickel alloy 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).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Incoloy 800H in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08810
- EN / DIN / Werkstoff-Nr.
- 1.4958
- Other
- B407/B408/B409Incoloy800H
How much does Incoloy 800H cost?
Incoloy 800H is a high-cost nickel alloy ($$$$), 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.
Incoloy 800H — frequently asked
What is Incoloy 800H used for?
Incoloy 800H is typically used for reformer/cracker tubes, high-temperature pressure vessels and heat treating fixtures. In short: creep-rated Alloy 800; coarse-grain, controlled carbon; 1100 °C furnace service.
What is the yield strength of Incoloy 800H?
Incoloy 800H has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 93% of nickel alloy grades. Strength varies by condition: see the 6 listed tempers.
Is Incoloy 800H easy to machine?
Not especially — machinability is rated poor (30/100, better than 90% of nickel alloy grades). Gummy and work-hardening — use rigid setups, positive-rake carbide, low speed (15–30 m/min) with heavy positive feed and copious sulphur-free coolant; never dwell in the cut.
Can Incoloy 800H be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/GMAW/SMAW with ERNiCr-3 or ENiCrFe-2/-3 filler, low heat input, no preheat, interpass <150 °C; keep sulphur/lead contamination off the joint and re-solution treat if full creep credit is required.
What surface finishes work on Incoloy 800H?
Pickle in HNO3-HF or grit blast plus passivation to remove green Cr-rich scale; not anodisable — protective service comes from the self-forming Cr2O3/spinel layer.
Can Incoloy 800H be formed, bent or molded?
Excellent cold formability at ~2× the force of 304; hot work at 1150–900 °C and finish above 900 °C, then solution anneal at 1120–1180 °C and rapid cool to restore the coarse ASTM 5 grain size.
What is the maximum service temperature of Incoloy 800H?
Incoloy 800H 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 Incoloy 800H-SA and Incoloy 800H-CW?
SA is the default condition — standard supply condition for ASME code high-temperature pressure parts, furnace tubing and plate. CW: use only where higher room-temperature strength/hardness is needed and long-term high-temperature (creep) service is not required. Yield strength is 220 MPa in SA versus 620 MPa in CW.
How much does Incoloy 800H cost?
Incoloy 800H is a high-cost nickel alloy ($$$$), 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 — Ni-Fe-Cr Alloy Plate, Sheet and Strip (UNS N08810) — ASTM International (2021)
- ASTM B407 / B408 / B564 — Ni-Fe-Cr Alloy Seamless Pipe & Tube, Rod & Bar, Forgings — ASTM International (2019)
- ASME BPVC Section II Part D — Allowable stresses, SB-409/SB-407 N08810 — ASME (2023)
- INCOLOY alloys 800H & 800HT — publication SMC-047 — Special Metals Corporation (2004)
- VDM Alloy 800 H / 800 HT material data sheet No. 4029 — VDM Metals (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- EN 10095 / W.Nr. 1.4958 heat-resisting steels and nickel alloys — CEN (1999)
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.