Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 800H Fasteners
TorqBolt manufactures the complete Incoloy 800H (UNS N08810) and Incoloy 800HT (UNS N08811) fastener range from ASTM B408 round bar and ASTM B564 forged blanks for petrochemical, refinery, fired-heater and pressure-vessel bolting service to 815 deg C (1500 deg F). Stud bolts, double-end studs, hex bolts, heavy hex bolts, socket head cap screws, anchor bolts, U-bolts, eye bolts, hex nuts, heavy hex nuts, lock nuts, coupling nuts, castle nuts, wing nuts, flat washers, spring washers, locking washers, threaded rod and all-thread bar are machined to ASME B18.2.1, ASME B18.2.2, DIN 931, DIN 933, DIN 934 and DIN 912 dimensional standards from Incoloy 800H alloy material certified to ASTM B408 (bar) or ASTM B564 (forgings). Every fastener ships with EN 10204 type 3.1 mill test certificate carrying heat number, chemistry, solution-anneal cycle, mechanical results and grain size verification, with type 3.2 third-party witness available on call-out.
Request a Quote on Incoloy 800H Bolts, Nuts, Studs and Washers
The TorqBolt Incoloy 800H Fastener Range
The matrix below lists every Incoloy 800H fastener variant TorqBolt machines in-house. Each variant has its own page covering dimensional callouts, manufacturing route, inspection rules and typical service applications. Click through to the variant page that matches your line item.
| Fastener category | Variant | Dimensional standard | Page |
|---|---|---|---|
| Bolts & Studs | Stud Bolts | ASME B16.5 + B18.2.1 dimensional | Stud Bolts |
| Tap End Studs | One-end threaded, plain shank | Tap End Studs | |
| Double End Studs | Both ends threaded, plain centre | Double End Studs | |
| Hex Bolts | DIN 931 / ISO 4014 | Hex Bolts | |
| Heavy Hex Bolts | ASME B18.2.1 | Heavy Hex Bolts | |
| Hex Cap Screws | DIN 933 / ASME B18.2.1 | Hex Cap Screws | |
| Socket Head Cap Screws | DIN 912 / ISO 4762 | Socket Head Cap Screws | |
| Anchor Bolts | Per project drawing | Anchor Bolts | |
| U-Bolts | Per pipe schedule | U-Bolts | |
| Eye Bolts | DIN 580 | Eye Bolts | |
| Nuts | Hex Nuts | ASME B18.2.2 / DIN 934 | Hex Nuts |
| Heavy Hex Nuts | ASME B18.2.2 | Heavy Hex Nuts | |
| Lock Nuts | DIN 985 (nylon insert) / DIN 980 (all-metal) | Lock Nuts | |
| Coupling Nuts | DIN 6334 (long hex) | Coupling Nuts | |
| Castle Nuts | DIN 935 / ASME B18.2.2 | Castle Nuts | |
| Wing Nuts | DIN 315 / DIN 7993 | Wing Nuts | |
| Washers | Flat / Spring / Locking | DIN 125 / DIN 127 / DIN 6798 | Washers |
| Rod Forms | Threaded Rod | Cut-to-length, dimensional per ASTM A193 | Threaded Rod |
| All-Thread Bar | Continuous all-thread bar stock | All-Thread Bar |
Manufacturing Route at TorqBolt
Incoloy 800H fasteners are machined from ASTM B408 round bar for shank diameters up to 100 mm and forged per ASTM B564 for larger blanks. The process sequence is fixed in the TorqBolt control plan:
| Step | Operation | Acceptance basis |
|---|---|---|
| 1 | Material receipt + heat verification against ASTM B408 / B564 PMI | Heat number, chemistry, EN 10204 type 3.1 cert traceable to melt |
| 2 | Cut to length on horizontal bandsaw | Length tolerance per print, square-end check |
| 3 | Centerless grind shank to bar tolerance (if required) | OD tolerance per print |
| 4 | Machine head profile (CNC turn-mill) for hex / heavy hex / socket geometries | Across-flats per ASME B18.2.1 / DIN 931 / DIN 912 |
| 5 | Thread roll or thread cut | Class 2A / class 6g per print; ring + plug gauge verification |
| 6 | Solution anneal 1149 deg C (2100 deg F) followed by rapid quench, ASTM grain size 5 or coarser | Grain-size etch (ASTM E112); hardness within 120-184 HB band |
| 7 | Dimensional + PMI + visual inspection | 100 percent dimensional; PMI on first piece and one per batch |
| 8 | Marking + heat-stamping per ASTM B408 + customer call-out | Heat number + grade marking on head; CoC issued |
| 9 | Packing + dispatch | VCI-wrapped, kraft inner, plywood crate; shipping marks per PO |
Service Envelope: Where Incoloy 800H Fasteners Are Specified
Incoloy 800H fasteners take service in the same hot-zone applications where the parent alloy holds its creep envelope. The selection driver is sustained operating temperature combined with oxidation, carburization and sulfidation resistance, not room-temperature tensile strength. Typical fastener applications are:
- Ethylene cracker tubes: flange bolting on radiant-section pigtail manifolds, header connections, and crossover fittings.
- Reformer pigtails: outlet pigtail flange bolting between catalyst tubes and outlet headers.
- Radiant tubes and furnace components: hearth-plate fixings, retort bolting, muffle fasteners.
- Steam superheater tubes: final-stage flange bolting on superheaters and reheaters.
- Heat exchanger tubes: tubesheet stud bolting on high-temperature process exchangers.
- ASME Section VIII pressure vessels: code-stamped flange bolting on vessels above 540 deg C (1000 deg F).
- Fired-heater radiant-section flange bolting in petrochemical and refining service.
- Combustion-air ductwork, expansion-joint flange bolting, refractory-anchor stud welding to vessel walls.
Standards Followed
The material standard sets the alloy. The dimensional standard sets the fastener geometry. TorqBolt operates against both layers simultaneously.
| Layer | Standard | Scope |
|---|---|---|
| Material (bar) | ASTM B408 | Incoloy 800H / 800HT round bar, OD 8-250 mm |
| Material (forgings) | ASTM B564 | Incoloy 800H forged blanks for large bolt heads, valve trim |
| Material (plate) | ASTM B409 | Plate stock for non-rotational fastener geometries |
| Dimensional (heavy hex) | ASME B18.2.1 | Heavy hex bolt + cap screw dimensions |
| Dimensional (heavy hex nut) | ASME B18.2.2 | Heavy hex nut dimensions |
| Dimensional (metric hex bolt) | DIN 931 / ISO 4014 | Metric hex bolt, M12-M48 |
| Dimensional (metric hex nut) | DIN 934 | Metric hex nut, M12-M48 |
| Dimensional (socket head) | DIN 912 / ISO 4762 | Socket head cap screw, M3-M48 |
| Code reference (PV) | ASME Section VIII | Pressure-vessel design temperature 815 deg C max |
Note on bolting-grade specifications: ASTM A193 and ASTM A194 are steel bolting specifications that include some nickel-base grades but do not cover Incoloy 800H. TorqBolt manufactures Incoloy 800H fasteners as alloy-material-certified per ASTM B408 / B564 and dimensionally machined to A193 / B18.2.1 geometry, not as A193 nickel-grade bolting.
Inspection and Certification
EN 10204 type 3.1 mill test certificate is supplied by default on every Incoloy 800H fastener line. The certificate carries:
- Heat number traceable to the melt source.
- Chemical analysis showing Ni 30-35, Cr 19-23, C 0.05-0.10, Al+Ti 0.30-1.20 (800H window).
- Solution-anneal cycle (1149 deg C plateau, hold time, rapid quench).
- Tensile + 0.2 percent proof stress + elongation results at room temperature.
- ASTM E112 grain size verification (grain size 5 or coarser).
- Hardness band 120-184 HB.
- Dimensional report cross-referenced to print.
- PMI (positive material identification) by X-ray fluorescence on first piece and one per batch.
EN 10204 type 3.2 with Lloyds Register, DNV, BV, SGS or TUV witness inspection is supplied on PO call-out and is standard practice on refinery, petrochemical and offshore procurement against API 660 heat-exchanger packages.
Fastener FAQ
Q. Can Incoloy 800H fasteners be supplied to ASTM A193 grade B8M or B8?
No. ASTM A193 grade B8M is steel-base 316 stainless and B8 is 304 stainless. Incoloy 800H is a separate nickel-iron-chromium alloy specified under ASTM B408 (bar) and ASTM B564 (forgings). TorqBolt manufactures Incoloy 800H fasteners machined to A193 dimensional geometry from B408 / B564 material, with the certificate referencing the correct alloy standard.
Q. What is the maximum service temperature for Incoloy 800H stud bolting?
ASME Section VIII Division 1 design tables list Incoloy 800H usable to 815 deg C (1500 deg F) for sustained service. Incoloy 800HT (UNS N08811) extends sustained service to 982 deg C (1800 deg F). Above that, step to Inconel 625 or Haynes 230.
Q. What is the thread tolerance class supplied?
Inch fasteners are supplied to class 2A (external) / 2B (internal) per ASME B1.1 unless the PO specifies class 3A/3B for high-precision assembly. Metric fasteners are supplied to class 6g (external) / 6H (internal) per ISO 965, with class 4g6g or class 4H5H available on call-out.
Q. Are coatings recommended on Incoloy 800H fasteners?
Generally no. Incoloy 800H is a corrosion-resistant nickel-base alloy and does not require zinc, cadmium or organic protective coatings in atmospheric service. Anti-seize compounds based on nickel are recommended on threaded joints exposed to elevated temperature to prevent galling on disassembly. Decorative coatings should not be applied without engineering review.
Q. What is the lead time on standard Incoloy 800H fasteners?
Stock sizes ship in 7 to 14 working days from PO release. Non-stock diameters, custom lengths and forged blanks larger than 100 mm OD run on 4 to 8 week lead time depending on bar / forging-blank availability and EN 10204 type 3.2 witness scheduling.
Request a Quote
Send drawing or PO line items to info@torqbolt.com or open the TorqBolt contact form. For ASTM B408 bar stock, see the round bar page. For forged blanks, see the forgings page. For the parent alloy datasheet, see the Incoloy 800H datasheet.
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