Tesco Steel & Engineering forges Incoloy 800 weld neck flanges — UNS N08800, Werkstoff Nr. 1.4876, the iron-nickel-chromium alloy of 30–35% nickel and 19–23% chromium, stabilized with titanium and aluminium — to ASTM B564, from 1/2″ NB to 56″ NB in ASME B16.5 Class 150–2500 and European PN patterns. The formula is deliberate economy: enough nickel for structural stability and chloride-SCC resistance, enough iron to undercut the high-nickel Inconels — the workhorse of heat exchangers, furnace hardware and hot process piping, with the creep-rated 800H (N08810) and 800HT (N08811) reformer grades forged alongside. Mating B407 pipe, welded with ERNiCr-3. Supplied with PMI and EN 10204 3.1/3.2 on request. ISO 9001:2015, made in Mumbai, India — exported worldwide.
Incoloy 800 · UNS N08800 · 1.4876Fe Base · Ni 30–35% · Cr 19–23%ASTM B564 / ASME SB-564Heat Exchangers · Furnace Duty800H / 800HT Creep Grades Too1/2″ – 56″ NB · Class 150–2500ISO 9001:2015 · Exported Worldwide
Incoloy 800 (UNS N08800 / 1.4876) is the iron-based branch of the nickel-alloy family: 30–35% nickel — enough for structural stability through decades of hot service and for chloride-SCC resistance — with 19–23% chromium for the oxidation scale, on an economical iron base stabilized with titanium and aluminium. An Incoloy 800 weld neck flange pairs that formula with a long tapered hub butt-welded to the pipe, forged to ASTM B564.
The family splits by creep: standard 800 covers general hot duty to ~593 °C design; 800H (N08810) holds carbon at 0.05–0.10% with coarse grain for code-listed creep strength; and 800HT (N08811) tightens the Al+Ti window for the best stress-rupture life — the steam-reformer and ethylene-furnace grade. All three forge here.
Against the nickel-based Inconel 600, alloy 800 trades chemistry headroom for price — the economist's choice when the service is hot but the environment ordinary. For chloride-rich immersion, the molybdenum-bearing Incoloy 825 is the family's wet-corrosion answer.
Also searched as: Alloy 800 flange, UNS N08800 flange, 1.4876 flange, X10NiCrAlTi32-20 flange, iron nickel chromium flange, reformer flange — all refer to the product on this page.
Chemical Composition of Incoloy 800
C
Mn
Si
S
Cu
Fe
Ni
Cr
Al
Ti
0.10 max
1.50 max
1.00 max
0.015 max
0.75 max
39.50 min
30.00-35.00
19.00-23.00
0.15-0.60
0.15-0.60
Values in weight %. The titanium and aluminium stabilize carbon and strengthen the matrix; in 800HT their combined window tightens to 0.85–1.20% for creep duty, while 800H holds carbon at 0.05–0.10% with coarse-grain practice.
Mechanical Properties of Incoloy 800
Tensile Strength, MPa
Yield Strength, Min, MPa
Elongation % min.
520
205
30
Minimums per ASTM B564 in the annealed condition — demonstrated on every certificate. For designs above ~593 °C, the coarse-grain 800H/800HT variants carry the code-listed creep and stress-rupture values.
Equivalent Grades of Incoloy 800
Standard
Werkstoff Nr.
UNS
JIS
BS
GOST
AFNOR
EN
OR
Incoloy 800
1.4876
N08800
NCF 800
NA 15
ЭИ670
Z8NC32-21
X10NiCrAlTi32-20
ХН32Т
The creep variants are 800H / UNS N08810 / 1.4958 and 800HT / UNS N08811 / 1.4959. System partners: ASTM B407 seamless pipe, B366 butt-weld fittings, B409 plate and B564 forgings.
Incoloy 800 Weld Neck Flange Specifications
Incoloy 800 Weld Neck Flanges are available in the following specifications:
Size
1/2"NB to 56"NB
Class
150#, 300#, 400#, 600#, 900#, 1500#, 2500#
Sch (Schedule)
XS, XXS, STD & Schedule 20, 40, 80, 160
Pressure Ratings
PN 2.5 - PN 400
Standards
ASTM B564 / ASME SB-564; ASME B16.5, ASME B16.47, EN 1092-1, DIN 2631–2635, BS 4504
Condition
Annealed; 800H / 800HT (solution annealed, coarse grain) available for creep service
A third nickel buys structural stability and chloride-SCC resistance; the iron base keeps the price far below the 60–70% nickel Inconels.
Stable for Decades
The Ti/Al-stabilized austenite neither sigma-embrittles like high-Cr stainless nor greys out in long hot service — exchangers run for plant lifetimes.
The Reformer Family
800H/HT's coarse-grain creep pedigree carries steam-methane reformers and ethylene furnaces to ~985 °C metal temperatures — forged alongside standard 800.
Stainless-Killer Duty
Feedwater heaters and hot aqueous systems that stress-crack 300-series stainless move up to 800 and stop cracking.
Full Incoloy Range In-House
800, 800H, 800HT, 825 and 925 flanges from one forge — the design temperature and chemistry pick the member, the certificates arrive matched.
Welding Incoloy 800 — 82 Filler, H/HT Discipline
Alloy 800 welds with ERNiCr-3 (Inconel 82) wire or ENiCrFe-2/-3 electrodes and nickel-alloy discipline: sulphur-free cleanliness, moderate heat input, no preheat, no PWHT in normal practice. For creep-range 800H/HT joints, specifications often call ERNiCrCoMo-1 (117-type) consumables so the weld matches the base metal's stress-rupture life.
Grade-selection note: design above ~593 °C belongs to 800H/800HT; chloride-rich immersion belongs to 825. State the temperature and chemistry in the enquiry and the grade follows.
Where Incoloy 800 Weld Neck Flanges Are Used
Heat exchangers and superheaters lead, then furnace hardware and hot-gas ducting, petrochemical fired heaters, steam-methane reformer and ethylene systems (in the H/HT grades), power plant auxiliaries and feedwater heaters, and hot chemical duty where stainless would stress-crack. Our nickel-alloy production below:
Incoloy 800 weld neck flanges share their dimensions with every other material in the same class — OD, thickness, hub, bore, bolt circle and bolting per the standard tables. Full ASME B16.5 charts:
Alloy 800 pricing tracks nickel plus the testing scope, so we quote live with a stated validity rather than publish a static list. To get a firm quotation, usually within 24 hours:
1
List your requirement — size (NB), class or PN, standard (ASME B16.5 / B16.47 / EN / DIN / BS), grade (800 — or 800H/800HT for creep design), pipe schedule or bore, and quantity.
2
State the service & testing scope — design temperature (it picks 800 vs H/HT), plus 3.2 witness, PMI, grain size or project specifications.
3
Send it across — via the inquiry form, WhatsApp, or email to sales@tescosteel.com — and we reply with price, delivery and stock position.
It is a weld neck flange forged from Incoloy 800 — the iron-nickel-chromium alloy of 30-35% nickel and 19-23% chromium on an iron base, stabilized with titanium and aluminium, UNS N08800 / 1.4876 — to ASTM B564. The long tapered hub is butt-welded to the pipe with the bore matched to the pipe schedule, giving a radiographable joint in the economical workhorse of hot process piping: heat exchangers, furnace hardware and reformer-adjacent systems.
What is the idea behind the Incoloy 800 chemistry?
Enough nickel, no more. Around a third nickel keeps the austenitic structure stable through decades of hot service and lifts the alloy past the chloride-SCC threshold that limits stainless — while the iron base keeps the price far below the 60-70% nickel Inconels. The 20% chromium builds the oxidizing-service scale, and small titanium and aluminium additions tie up carbon and strengthen the matrix. It is deliberately the economist among the heat alloys.
What is the difference between Incoloy 800, 800H and 800HT?
Creep tuning. Standard 800 allows carbon to 0.10% with no floor — the general-purpose grade to about 593 °C design. 800H (UNS N08810) requires carbon at 0.05-0.10% with coarse grain, buying code-listed creep strength. 800HT (N08811) further tightens the aluminium-plus-titanium window to 0.85-1.2% for the best stress-rupture performance — the reformer and ethylene-furnace grade. We forge all three; the design temperature picks the member.
What is the difference between Incoloy 800 and Inconel 600?
The base metal, and the budget. Inconel 600 is nickel-based (72% min) — stronger caustic and halogen chemistry, higher temperature ceiling, higher price. Incoloy 800 is iron-based with a third nickel — the same family virtues in economy class, entirely adequate for heat exchangers, hot air and most furnace duty. When the chemistry gets aggressive the Inconels take over; when it is heat plus ordinary environments, 800 carries the plant.
What are the equivalent designations for Incoloy 800?
UNS N08800; Werkstoff Nr. 1.4876; EN X10NiCrAlTi32-20; JIS NCF 800; BS NA 15; GOST ЭИ670 (ХН32Т); AFNOR Z8NC32-21; and the trade names Incoloy 800 or Alloy 800. System partners: ASTM B407 seamless pipe, B366 butt-weld fittings, B409 plate and B564 forgings. An enquiry in any of these designations is quoted as the same material.
What is the chemical composition of Incoloy 800?
Per ASTM B564: iron 39.50% minimum, nickel 30.00 to 35.00%, chromium 19.00 to 23.00%, aluminium 0.15 to 0.60%, titanium 0.15 to 0.60%, with residuals capped at carbon 0.10%, manganese 1.50%, silicon 1.00%, copper 0.75% and sulphur 0.015%. The Ti and Al stabilize carbon and strengthen the matrix; in the 800HT variant their combined window tightens for creep duty.
What are the mechanical properties of Incoloy 800 flanges?
Per ASTM B564 in the annealed condition: tensile strength 520 MPa (75 ksi) minimum, yield strength 205 MPa (30 ksi) minimum and elongation 30% minimum, demonstrated on every certificate. For designs above about 593 °C, the coarse-grain 800H and 800HT variants carry the code-listed creep and stress-rupture values.
Which pipe and fittings do Incoloy 800 weld neck flanges mate with?
ASTM B407 seamless Incoloy 800 pipe is the standard partner, with B366 butt-weld fittings and B409 plate completing the system. The weld neck bore is machined to the pipe schedule you state, so the bore runs flush through the joint and the bevel arrives ready for a matched-chemistry butt weld.
How are Incoloy 800 flanges welded to pipe?
With ERNiCr-3 (Inconel 82) wire or ENiCrFe-2/-3 electrodes and nickel-alloy discipline: sulphur-free cleanliness, moderate heat input, no preheat, no PWHT in normal practice. For creep-range 800H/HT joints, specifications often call ERNiCrCoMo-1 (117-type) consumables so the weld matches the base metal's stress-rupture life.
What temperature range can Incoloy 800 flanges be used in?
Standard 800 serves general hot duty with oxidation resistance to about 1093 °C and code design typically to 593 °C, above which the H and HT grades carry the creep ratings — 800HT serving reformer and ethylene systems toward 985 °C metal temperatures. At the cold end the austenitic structure keeps full toughness. The universal sulphur-atmosphere caution applies, though the iron base tolerates sulphur better than the high-nickel Inconels.
Is Incoloy 800 resistant to chloride stress corrosion cracking?
Effectively yes — at 30-35% nickel the alloy sits above the SCC threshold that limits 300-series stainless, which is why feedwater heaters and hot aqueous systems that crack stainless move up to 800. It is not, however, a pitting specialist: for chloride-rich immersion the molybdenum-bearing 825 is the family's answer.
Why is Incoloy 800H/HT the reformer alloy?
Steam-methane reformers and ethylene furnaces run continuous metal temperatures of 800-985 °C for years — pure creep territory. 800H/HT's coarse-grain, controlled-chemistry structure carries certified stress-rupture values there while resisting oxidation and carburization, and decades of pigtail, header and manifold service made it the industry standard. Flanged connections on those systems specify the same alloy — which we forge alongside standard 800.
What testing and certification do you supply with Incoloy 800 flanges?
Every lot ships with EN 10204 3.1 mill test certificates covering chemical analysis — demonstrating the nickel, chromium, titanium and aluminium windows — mechanical properties and the anneal record (with grain size reporting for H/HT), with 3.2 certification witnessed by Lloyd's, DNV, BV or TÜV on request. We also offer PMI verification, hydrostatic testing and dye-penetrant examination, with full heat-number traceability.
Where are Incoloy 800 weld neck flanges used?
Heat exchangers and superheaters, furnace hardware and hot-gas ducting, petrochemical fired heaters, steam-methane reformer and ethylene systems (in the H/HT grades), power plant auxiliaries, feedwater heaters, and hot chemical duty where stainless would stress-crack. Wherever the service is hot but the chemistry ordinary, alloy 800 is the economical answer.
What sizes and standards do you manufacture Incoloy 800 weld neck flanges in?
From 1/2 inch NB to 56 inch NB: ASME B16.5 Class 150 to 2500 up to 24 inch, ASME B16.47 above, and European PN 2.5 to PN 400 patterns to EN 1092-1, DIN and BS 4504. Raised face is standard, ring joint on request, and every bore is machined to the mating pipe schedule from Sch 10 through XXS.
Do you keep Incoloy 800 weld neck flanges in stock? What is the lead time?
Alloy 800 moves in project quantities, so common exchanger and furnace sizes in Class 150 and 300 rotate through production with popular items often available, while larger diameters, higher classes, 800H/HT and witness-tested lots are forged to order — typically 4 to 6 weeks. Prices track nickel, so quotations carry a validity period.
Do you export Incoloy 800 flanges outside India?
Yes. Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer based in Mumbai, and Incoloy 800 flanges ship to petrochemical, power and furnace projects across the Middle East, Europe, Africa, Southeast Asia and the Americas. Flanges travel face-protected and seaworthy-packed, with full heat-number and test traceability.
