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Incoloy 800, 800H, 800HT Fasteners Supplier in Mumbai, India -Bolts and Nuts
Nicorex Alloys is ISO 9001 / ISO 14001 certified supplier, importer, and stockist of Incoloy 800 series fasteners in Mumbai, India. We specialise in Incoloy 800 series fasteners and offer high-quality bolts and studs that are designed to retain the integrity of the structure even at high temperatures.
Three grades, one iron-nickel-chromium family. Incoloy 800, Alloy 800H, and Alloy 800HT share an identical base of 30–35% Ni, 19–23% Cr, and 39.5% Fe min. The margins are narrow but essential: controlled carbon, more aluminium and titanium, and a coarse grain size requirement combine to give 800H and 800HT the creep-rupture strength required to maintain furnace bolts under constant load even after 100,000 hours of operation at 750°C. Incoloy 800H offers equal oxidation and carburisation resistance at 50-60% lower cost because of the 40% iron content, which makes the material significantly cheaper. Sigma-phase immunity in the range of 649–871°C (1200–1600°F) is the primary reason engineers use it. These fasteners are specifically stocked for ethylene cracker furnace bolting, reformer tube hanger studs, and nuclear steam generator equipment, where performance and cost-efficiency are equally critical.
Manufactured per ASTM B408 (bar) and ASTM B564 (forgings). UNS N08800 / N08810 / N08811, Werkstoff 1.4876 / 1.4958 / 1.4959. Tensile: 450 MPa (65 ksi). Yield: 170 MPa (25 ksi). Types: Incoloy 800 hex bolts, Alloy 800H stud bolts, Incoloy 800HT nuts, SHCS, lock nuts, washers, threaded rods, U-bolts, eye bolts, and set screws. Sizes: M6 to M100 / 1/4” to 4”. ASME Code Case 1987 (800HT). Triple-certified material (N08811 meets N08810 and N08800) is available.
Incoloy Alloy 800/H/HT Fastener Specifications
| Standard | ASTM B408 / ASME SB-408; ASTM B564 / ASME SB-564 |
|---|---|
| Forms | Bolts, Nuts, Screws, Washers, Studs, Threaded Rods, Hex Bolts, Socket Head Cap Screws, Hex Nuts, Lock Nuts, Stud Bolts |
| Size | M6 – M100 (Metric); 1/4″ – 4″ (Imperial) |
| Length | 3 mm – 200 mm; Custom lengths available |
| Diameter | M6 – M100 (Metric); 1/4″ – 4″ (Imperial) |
| Thread Types | UNC, UNF, Metric Coarse, Metric Fine, BSW, BSF |
| Surface Finishes | Bright Finish, Pickled, Passivated, Hot-Dip Galvanised, Electropolished |
| Available Conditions | Solution Annealed |
Chemical Composition of Alloy 800, 800H, and 800HT Fasteners
| Grade | Ni | Cr | Fe | C | Al | Ti | Al+Ti | Mn | Grain Size |
|---|---|---|---|---|---|---|---|---|---|
| 800 (N08800) | 30.0–35.0 | 19.0–23.0 | 39.5 min | 0.10 max | 0.15–0.60 | 0.15–0.60 | 0.30–1.20 | 1.50 max | Not specified |
| 800H (N08810) | 30.0–35.0 | 19.0–23.0 | 39.5 min | 0.05–0.10 | 0.15–0.60 | 0.15–0.60 | 0.30–1.20 | 1.50 max | ASTM 5 or coarser |
| 800HT (N08811) | 30.0–35.0 | 19.0–23.0 | 39.5 min | 0.06–0.10 | 0.25–0.60 | 0.25–0.60 | 0.85–1.20 | 1.50 max | ASTM 5 or coarser |
800H and 800HT require higher controlled carbon (0.05–0.10%). This carbon forms M₂₃C₆ chromium carbides at grain boundaries during high-temperature service, pinning boundaries against sliding, the primary creep failure mechanism. 800HT restricts Al+Ti to 0.85–1.20% (high end only), contributing to improved creep resistance. Coarse grains (ASTM 5 or larger) reduce total boundary area, further improving creep life.
Triple certification: Material produced to 800HT chemistry (N08811) meets 800H (N08810) and 800 (N08800) requirements. A single heat can carry all three UNS numbers on the MTC.
Mechanical Properties of Incoloy 800/800H/800HT Series Fasteners
| Property | Tensile Strength (min) | Yield 0.2% (min) | Elongation (min) | Hardness |
|---|---|---|---|---|
| Value | 450 MPa (65 ksi) | 170 MPa (25 ksi) | 30% | 126–170 HB (70–85 HRB) |
Differences emerge only in elevated-temperature creep-rupture behaviour. Approximate 100,000-hour stress-rupture strengths: at 649°C -800: 62 MPa, 800H: 69 MPa, 800HT: 76 MPa. At 816°C -800: 17 MPa, 800H: 21 MPa, 800HT: 24 MPa. At 900°C -800H: 10 MPa, 800HT: 12 MPa (800 not recommended above 816°C).
Alloy 800 fasteners are NOT selected for room-temperature preload. A bolt that maintains 70% of its clamp load after 100,000 hours at 750°C is far more valuable than a stronger bolt that relaxes to zero. ASME BPVC limits bolting to 899°C (1650°F) for N08810/N08811.
Alloy 800H and 800HT Equivalent Grades and Cross-Reference
| Standard System | UNS | Werkstoff Number | DIN | EN | JIS |
|---|---|---|---|---|---|
| Equivalent Grade | N08800 / N08810 / N08811 | 1.4876 / 1.4958 / 1.4959 | X10NiCrAlTi32-21 | X10NiCrAlTi32-21 | NCF 800 / NCF 800H |
Get Incoloy 800 Fasteners at Competitive Prices
Types of Incoloy 800 Fasteners Available
Incoloy 800 Hex Bolts
Incoloy 800H Stud Bolts
Socket Head Cap Screws
Incoloy 800 Hex Nuts
Nickel Alloy 800 Lock Nuts
Alloy 800H Flat Washers
Incoloy 800HT Threaded Rods
Incoloy Alloy 800HT U-Bolts
Incoloy 800H Set Screws
Incoloy 800 Eye Bolts
Surface Finish and Coating Options for Alloy 800 Fasteners
- Plain / Self-Colour: Standard for elevated-temperature service – inherent Cr₂O₃ oxide provides protection
- Passivated: Acid passivation per ASTM A967 – removes free iron from machining
- Silver Plated: Anti-seize and anti-galling for repeated assembly/disassembly at high temperature. Silver remains effective as a lubricant at elevated temperatures (verify specific temperature rating with plating supplier).
- Molybdenum Disulphide (MoS₂) Coated: Dry lubricant for fasteners operating above 400°C in inert or vacuum environments
- Nickel-Based Anti-Seize: Standard recommendation for assembly. Copper-based anti-seize acceptable but limited to ~980°C.
- PTFE Coated: Anti-galling for ambient-temperature flanged connections
IMPORTANT: Alloy 800 series fasteners operating above 600°C require careful anti-seize selection. Conventional petroleum-based lubricants carbonise and seize the threads. Use ONLY high-temperature anti-seize compounds rated for the target operating temperature.
Industries and Applications for Incoloy 800H Fasteners
- Ethylene cracker furnace tube hanger studs (800HT), steam-methane reformer pigtail flange bolting, catalytic reformer header studs, pyrolysis tube support fasteners.
- Superheater/reheater header flange studs (800H), boiler baffle bolting, HRSG duct fasteners, coal gasifier internal bolting.
- Steam generator tube support plate bolting (Incoloy 800), PWR internals. ASME BPVC Section III qualified (Code Cases N-253, N-254).
- Radiant tube hanger bolts (800HT), conveyor belt support studs, muffle furnace fixings, carburising furnace basket bolting.
- Nitric acid condenser flange bolting, vinyl chloride monomer plant fasteners. Recovery boiler superheater studs. Exhaust ducting flange bolts, turbine exhaust casing studs.
How to Order Alloy 800 Fasteners from Nicorex Alloys
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Fastener Type - Hex Bolt, Stud Bolt, Socket Head Cap Screw, Nut, Washer, Threaded Rod, Anchor Bolt
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Size - Diameter × Length in mm or inches
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Thread Type - UNC, UNF, BSW, Metric Coarse/Fine
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Material Grade - Incoloy 800 / UNS N08800, 800H / UNS N08810, 800HT / UNS N08811
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Standard - ASTM F468 / ASTM F467 / ASME SA193 B8 Class 1
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Finish - Bare, Passivated, Pickled
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Condition - Solution Annealed
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Quantity - Number of Pieces or kg
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Additional Requirements - Specific Heat Numbers, High-Temperature Service, Furnace / Petrochemical Application
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Documentation - MTC 3.1 per EN 10204, PMI report, third-party inspection certificate
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Packaging - Standard wooden box / export-grade sea-worthy packing / ISPM 15 compliant
- Delivery Destination - Domestic / International
Tip: If operating temperature exceeds 593°C, specify 800HT (N08811) by default. It triple-certifies as 800H and 800, giving maximum flexibility and the highest ASME allowable stresses.
Frequently Asked Questions
What is the Price of Incoloy 800 Fasteners per Kg in India?
Prices range ₹1,800–₹4,000/kg depending on grade, size, and certification. Alloy 800HT commands a modest premium due to tighter chemistry controls and mandatory grain size verification. Triple-certified material represents the best procurement value.
What is the Difference Between Incoloy 800, 800H, and 800HT?
Why Specify Alloy 800H Bolting Instead of Stainless Steel 304 or 321?
Two reasons. Sigma-phase immunity: Types 304, 316, 321, and 347 develop brittle sigma phase after prolonged exposure to 600–900°C, causing sudden bolt fracture during shutdown thermal cycling. Alloy 800H resists sigma formation due to its 32% Ni content. Superior creep life: 800H studs maintain meaningful clamp force for 100,000+ hours at 750°C, far exceeding any austenitic stainless steel.
What Anti-Seize Should Be Used on Incoloy 800 Series Studs for High-Temperature Service?
Above 500°C, use nickel-based anti-seize rated to 1315°C (e.g., Loctite N-5000). Copper-based anti-seize is acceptable to ~980°C. Never use petroleum-based or MoS₂ compounds above 400°C in oxidising atmospheres. Silver plating on threads is the most reliable solution for repeated high-temperature assembly/disassembly cycles.