Hex Head & Heavy Hex Bolts
Engineered for high-pressure flanged connections, turbine housings, and high-load piping systems.
Sizes: M6–M100 | 1/4"–4"
ISO 9001:2015Certified Quality Management
PED 2014/68/EUApproved by TUV Rheinland
EN 10204 3.1 / 3.2100% Heat-Number Traceability
Global EngineeringExporting to 40+ Countries
Superalloy Bolting Expertise
Engineering Integrity for Extreme Operating Envelopes
Inconel is an advanced nickel-chromium-based superalloy engineered for demanding mechanical and thermal duties where standard stainless steels and austenitic alloys fail. As a precision manufacturer based in India, TorqBolt Inc. produces standard and custom-machined Inconel fasteners designed to maintain superior tensile strength, creep resistance, and chemical stability across temperatures spanning -250 °C up to 1000 °C.
Our dedicated manufacturing infrastructure utilizes state-of-the-art hot forging presses and multi-axis CNC turn-mill centers. Because Inconel superalloys exhibit intense work-hardening characteristics, our process engineers implement controlled thermal profiles, precision hot-roll threading, and calibrated solution-annealing sequences to ensure maximum grain continuity, fatigue life, and 100% thread integrity.
Available Form Factors
Inconel Fastener Configurations
Manufactured to ASME B18.2.1, DIN 931, DIN 933, ISO 4014, and tailored client drawings, our Inconel hardware delivers dependable joint tightness across pressure boundaries.
Stud Bolts & Threaded Rod
Continuous-thread, double-end, and tap-end stud bolts for ASME B16.5 and B16.47 pressure flanges.
Standards: ASTM A193 / A453 / A540
Hex Nuts & Lock Nuts
Precision-matched hex, heavy hex, jam, and prevailing torque lock nuts to mitigate galling risks.
Standards: ASME B18.2.2, DIN 934, ISO 4032
Washers & Custom Rings
Flat, Belleville spring, hardened, and custom-profile sealing rings for sustained preload stability.
Standards: ASME B18.21.1, DIN 125, DIN 127
Metallurgical Portfolio
Inconel Grade Engineering & Selection
Choosing the appropriate superalloy requires careful analysis of operational temperatures, stress factors, and specific chemical corrosion mechanisms.
UNS N07718 | W.Nr. 2.4668
Inconel 718 Fasteners
A precipitation-hardenable superalloy reinforced by niobium and molybdenum precipitates. Delivers exceptional tensile, yield, and creep-rupture strength up to 650 °C (1200 °F).
- Tensile Strength: ≥ 1240 MPa (180 ksi)
- Key Uses: Gas turbines, subsea wellhead trees, cryogenic storage
UNS N06625 | W.Nr. 2.4856
Inconel 625 Fasteners
Solid-solution strengthened by molybdenum and niobium. Provides superior pitting, crevice, and intergranular corrosion resistance in marine and acidic environments without post-weld aging.
- Tensile Strength: ≥ 825 MPa (120 ksi)
- Key Uses: Seawater piping, scrubbers, offshore risers, reactors
UNS N06600 | W.Nr. 2.4816
Inconel 600 Fasteners
High-nickel matrix resistant to chloride-ion stress-corrosion cracking and dry chlorine exposure. Offers high strength and oxidation immunity from cryogenic levels up to 1093 °C.
- Tensile Strength: ≥ 550 MPa (80 ksi)
- Key Uses: Thermal processing equipment, nuclear steam generators
UNS N06601 | W.Nr. 2.4851
Inconel 601 Fasteners
Contains aluminum additions that form a tightly adherent protective oxide scale, giving outstanding resistance to high-temperature oxidation and thermal spalling up to 1150 °C.
- Tensile Strength: ≥ 550 MPa (80 ksi)
- Key Uses: Industrial furnaces, petrochemical crackers, radiant tubes
UNS N07750 | W.Nr. 2.4669
Inconel X-750 Fasteners
Precipitation-hardened by titanium and aluminum additions. Retains elevated relaxation resistance and mechanical elasticity up to 700 °C under constant thermal fatigue loading.
- Tensile Strength: ≥ 1100 MPa (160 ksi)
- Key Uses: Belleville spring washers, rocket impellers, turbine bolts
UNS N06617 | W.Nr. 2.4663
Inconel 617 Fasteners
Nickel-chromium-cobalt-molybdenum composition delivering high metallurgical stability, high creep rupture resistance, and cyclic oxidation protection above 980 °C.
- Tensile Strength: ≥ 690 MPa (100 ksi)
- Key Uses: Combustion cans, transition liners, power generation
| Grade | UNS Number | Applicable Standard | Operating Limits | Notable Engineering Property |
|---|---|---|---|---|
| Inconel 718 | UNS N07718 | ASTM B637, AMS 5662 / 5663 | -250 °C to 650 °C | Highest yield strength; exceptional fatigue and creep-rupture performance |
| Inconel 625 | UNS N06625 | ASTM B446, AMS 5666 | Cryogenic to 980 °C | PREN > 50; immune to pitting and chloride stress corrosion |
| Inconel 600 | UNS N06600 | ASTM B166, DIN 17752 | Sub-zero to 1093 °C | High resistance to chloride cracking, caustic corrosion, and nitriding |
| Inconel 601 | UNS N06601 | ASTM B166, DIN 17752 | Up to 1150 °C | Dense Al₂O₃ oxide film resists extreme cyclic oxidation and thermal spalling |
| Inconel X-750 | UNS N07750 | ASTM B637, AMS 5667 | Up to 700 °C | Superior spring relaxation resistance under prolonged elevated temperatures |
* Material certificates provided per EN 10204 Type 3.1 as standard. Dual-certified or NACE-compliant lots must be specified upon request.
Quality & Assurance
Inspection & Verification Protocol
TorqBolt enforces full metallurgical and dimensional testing protocols to guarantee that every fastener complies with relevant international standards and end-user specifications.
EN 10204 Type 3.1 Standard manufacturer test report providing heat chemistry and physical results
EN 10204 Type 3.2 Third-party witnessed inspection by DNV, TUV, BV, or Lloyd's Register
PED 2014/68/EU Module H Full quality assurance qualification for European pressure vessel equipment
NACE MR0175 / ISO 15156 Hardness-controlled manufacturing for hostile H₂S sour gas environments
All production batches are linked to a single heat number stamped on the fastener head. Raw bars are acquired exclusively from premier, ISO-certified melting mills with full chemical traceability.
Batch Testing Procedures
Our quality control laboratory conducts comprehensive non-destructive and destructive testing per governing specifications:
- 100% Positive Material Identification (PMI)
- Room and Elevated Temperature Tensile Testing
- Rockwell & Brinell Hardness Mapping
- Intergranular Corrosion (IGC) Evaluation
- Microstructure & Grain Size Analysis
- Liquid Penetrant Examination (DPI/PT)
- Charpy V-Notch Impact Testing (to -196 °C)
- Optical Thread Geometry & Pitch Verification
Technical FAQ
Frequently Asked Questions
What material grades are covered in TorqBolt's Inconel fastener line?
We manufacture fasteners across the entire Inconel family, including Inconel 600 (UNS N06600), Inconel 601 (UNS N06601), Inconel 625 (UNS N06625), Inconel 718 (UNS N07718), and Inconel X-750 (UNS N07750), strictly compliant with ASTM B637, ASTM B446, AMS 5662, and related international standards.
What size range and thread standards can TorqBolt supply in Inconel?
We supply metric sizes from M6 up to M100 and imperial dimensions from 1/4" up to 4" in diameter, with length capacities extending from 10 mm to 3000 mm. Thread geometries include UNC, UNF, 8UN, metric coarse, and metric fine, manufactured via precision thread rolling or CNC cutting.
Are TorqBolt Inconel fasteners suitable for sour service under NACE MR0175 / ISO 15156?
Yes. Fasteners manufactured from Inconel 625 and Inconel 718 can be supplied fully certified to NACE MR0175 / ISO 15156 and API 6A CRA requirements, featuring validated solution annealing, controlled age hardening, and documented hardness limits.
What quality documentation is provided with Inconel bolting?
Every shipment is accompanied by an EN 10204 3.1 Inspection Certificate providing complete chemical, mechanical, and 100% heat-number traceability. Independent third-party inspection (EN 10204 3.2) witnessed by agencies such as DNV, Lloyd's Register, TUV, BV, or ABS is regularly executed upon customer request.
What are typical manufacturing lead times for custom Inconel fasteners?
Fast-moving sizes and stock bar shapes can be delivered within 1 to 2 weeks. Custom production runs involving hot forging, specialized heat treatments, or non-standard thread pitches typically ship within 3 to 5 weeks.