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Incoloy 800HT Bolts Manufacturer & Exporter in India

Explore Incoloy 800HT Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-196

Min Temp

870

Max Temp

🌡

870

Suitable for continuous service up to approximately 870°C under typical operating conditions.

⚡

620

Typical tensile strength around 620 MPa depending on product form and heat treatment.

🛡

Very Good

Very Good corrosion resistance in a wide range of industrial environments.

⚖

8

Typical density is approximately 8.0 g/cm³.

Product Overview

What are Incoloy 800HT Bolts?

Incoloy 800HT bolts are high-temperature nickel-iron-chromium alloy fasteners manufactured from UNS N08811 bar stock in accordance with ASTM B408. The alloy’s enhanced carbon (0.06-0.10%) and aluminum/titanium content (Al + Ti: 0.85-1.20%) provide superior creep and rupture strength at elevated temperatures up to 1100°C, making them ideal for critical bolted joints in heat-exposed environments.

Incoloy 800HT bolts are specified for use in petrochemical reformers, furnace hardware, and superheater assemblies where resistance to oxidation, carburization, and thermal fatigue is essential. All bolts are supplied with full traceability and EN 10204 3.1 certification.

Quick Specifications

MaterialIncoloy 800HT
UNS NumberN08811
DIN Number1.4959 / 1.4876
Material StandardASTM B408
Bolt Standard (Metric)DIN 931 / DIN 933 / ISO 4014
Bolt Standard (Inch)ASME B18.2.1
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M64 / ¼"-2½"
Tensile Strength600 MPa (87 ksi) min
Yield Strength300 MPa (44 ksi) min
HardnessMax 85 HRB / 200 HB
? All material certified by NABL-accredited laboratory. PMI and grain size verification available on request.

Complete the Fastener Set

Other Incoloy 800HT Fastener Products Available from RealBolt

RealBolt also manufactures the complete Incoloy 800HT fastener range from certified iron-nickel-chromium alloy bar stock, including Incoloy 800HT Nuts, Incoloy 800HT Screws, Incoloy 800HT Washers, Incoloy 800HT Studs, and Incoloy 800HT Threaded Rods. All Incoloy 800HT fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Incoloy 800HT Nuts
Incoloy 800HT Screws
Incoloy 800HT Washers
Incoloy 800HT Studs
Incoloy 800HT Threaded Rods

Technical Data

Incoloy 800HT Bolts Dimensions, Sizes & Thread Standards

Incoloy 800HT Bolts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 931 (partial thread) / DIN 933 (full thread) / ISO 4014. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.2.1. All Incoloy 800HT bolts dimensions are verified against applicable DIN, ISO, and ASME

Hex Bolt Dimensions - Metric (DIN 931 / ISO 4014)

Size (M)Pitch (mm)A/F (mm)Head Ht (mm)Min L (mm)Max L (mm)
M61.0104.010200
M81.25135.312250
M101.5176.416300
M121.75197.520400
M162.02410.025500
M202.53012.530600
M243.03615.040600
M303.54618.750800
M364.05522.5601000
M424.56526.0801000
M485.07530.01001200
M565.58535.01201500
M646.09540.01402000

Dimensional & Material Standards

StandardCoversThread
DIN 931Hex bolts, partial threadMetric
DIN 933Hex bolts, full threadMetric
ISO 4014Hex head screws, partialMetric
ISO 4017Hex head screws, fullMetric
ASME B18.2.1Hex & heavy hex boltsUNC/UNF
ASME B16.5Stud bolts for flangesUNC
MSS SP-75Stud bolts, high-pressureUNC
Material StandardRequirement
ASTM B408Bar/rod - UNS N08811
ASTM F468Fastener mechanical
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Incoloy 800HT Chemical Composition

Incoloy 800HT Bolts are produced from an iron-nickel-chromium alloy with controlled nickel (30–46%), chromium (19–23%), and molybdenum content per ASTM. Nickel and chromium together resist high-temperature oxidation to 1093°C in 800H grades, while molybdenum and copper additions in Incoloy 825 provide sulfuric and phosphoric acid resistance.

Chemical Composition per ASTM B408

ElementComposition (%)
Nickel (Ni)30.0-35.0%
Chromium (Cr)19.0-23.0%
Iron (Fe)39.5% min (balance)
Carbon (C)0.06-0.10%
Aluminum (Al)0.25-0.60%
Titanium (Ti)0.25-0.60%
Al + Ti0.85-1.20%
Manganese (Mn)1.5% max
Silicon (Si)1.0% max
Sulfur (S)0.015% max
Copper (Cu)0.75% max
? All heats verified by NABL-accredited spectrometry. PMI and grain size verification available on request.

Why Incoloy 800HT Alloy Composition Matters for Bolts

Al + Ti (0.85–1.20%) — Creep & Rupture Strength
The combined aluminum and titanium content in Incoloy 800HT forms a stable gamma prime phase, dramatically improving creep and rupture resistance at temperatures above 600°C — essential for long-term bolted joints in furnaces and reformers.
Low Carbon (0.06–0.10%) — Intergranular Corrosion Resistance
The controlled carbon content minimizes carbide precipitation, ensuring resistance to intergranular attack after welding or prolonged exposure to high temperatures.
Nickel-Chromium Matrix — Oxidation & Carburization Resistance
The high nickel and chromium levels provide outstanding resistance to oxidation, carburization, and nitriding atmospheres, making Incoloy 800HT bolts reliable in aggressive furnace and petrochemical environments.

Fastener Performance

Incoloy 800HT Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Incoloy 800HT Bolts per ASTM. Incoloy 800HT bolts achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12705625
M1617013660
M2034027295
M24590472140
M301180944220
M3620501640320
M4232502600440
M4848003840600
?? Anti-galling: Use nickel-based anti-seize (Molykote P-37 or equivalent). Lubricated values assume K=0.15. Avoid copper-based anti-seize on nickel alloys.

Industry Applications

Incoloy 800HT Bolts Applications — Industries & End Uses

Incoloy 800HT Bolts from RealBolt are specified across petrochemical furnaces, chemical processing, nuclear, and power generation where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Incoloy 800HT bolts are the industry standard for bolted joints in steam/hydrocarbon reformers, ethylene cracking furnaces, and ammonia plant radiant coils. Their high creep strength and oxidation resistance ensure reliable service in tube sheets, manifolds, and radiant coil supports at temperatures up to 1100°C.
Used for superheater header connections, HRSG ductwork, and boiler tube supports where thermal cycling and high-temperature oxidation would cause failure in standard stainless steel bolts. Incoloy 800HT maintains mechanical integrity and prevents bolt relaxation.
Specified for furnace door hardware, muffle furnace assemblies, and heat treatment baskets where resistance to carburization, nitriding, and scaling is critical. The alloy’s stability prevents bolt embrittlement and maintains preload at elevated temperatures.
Ideal for bolted closures in nitric acid, acetic acid, and urea reactors, as well as for heat exchanger channel covers and pressure vessel nozzles exposed to aggressive chemical and thermal environments.

Incoloy 800HT Bolts Standards & International Certifications

Incoloy 800HT Bolts from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, PMI (XRF), NACE MR0175/ISO 15156, and NABL-accredited lab reports — available on request for all orders.
Standards
DIN 931 DIN 933 ISO 4014 ISO 4017 ASME B18.2.1 IS 1364 IS 1367
Certifications
ISO 9001:2015PED 2014/68/EUNABL LabEN 10204 3.1 / 3.2

Buy Incoloy 800HT Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Incoloy 800HT Bolts — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
022-6743-7972
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Answers for Buyers

Incoloy 800HT Bolts — Frequently Asked Questions

Browse expert answers to common questions about Incoloy 800HT Bolts from RealBolt — covering grade differences, ASTM B408/B425 standards, oxidation limits, acid resistance, sizes, and MTC documentation. Contact our technical team directly for project-specific guidance on Incoloy 800HT bolts selection and pricing.
Incoloy 800HT bolts are available to DIN 931 (metric partial thread), DIN 933 (metric full thread), ISO 4014/4017, and ASME B18.2.1 (inch hex and heavy hex). Stud bolts for flanges are supplied per ASME B16.5 and MSS SP-75. Custom thread forms (BSW, BSF, Whitworth) can be manufactured on request with a typical lead time of 2-3 weeks.
Use a nickel-based anti-seize compound (such as Molykote P-37 or Jet-Lube Pure Nickel) on all threads and nut bearing faces. This prevents galling and seizing at high temperatures. Lubricated torque values should be reduced by 20% compared to dry assembly. Avoid copper-based anti-seize to prevent galvanic corrosion.
Yes – Incoloy 800HT bolts are engineered for continuous service at temperatures up to 1100°C. Their high creep and rupture strength, combined with resistance to oxidation and carburization, make them ideal for furnace, reformer, and superheater bolting where standard stainless steels would fail.
There is no formal MOQ for standard sizes (M12-M36) available ex-stock – we supply from single pieces for urgent maintenance. Custom sizes or non-standard threads typically require a 10 kg minimum. Flange stud bolt sets are supplied per set with no minimum. Quantity discounts apply at 50 pcs, 200 pcs, and 500 pcs.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
  • Canada
  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil