Hex Head Bolts
Fully and partially threaded hex bolts and heavy hex structural bolts for flanges, valves and equipment.
Standards: ASME B18.2.1, ISO 4014 / 4017, DIN 931 / 933
View Hex Head Bolts 
ISO 9001:2015Certified quality management
PED 2014/68/EUApproved by TUV Rheinland
EN 10204 3.1 / 3.2Heat-number traceability
Since 2010Exporting worldwide
Specialty Fasteners Manufacturer in Exotic & Corrosion-Resistant Alloys
TorqBolt Inc. engineers and manufactures hard-to-find bolts, stud bolts, nuts, washers and threaded rod in Inconel, Hastelloy, Monel, Duplex and Super Duplex, Titanium and Copper Nickel for critical service in oil & gas, petrochemical, power, marine and aerospace.
Our head office in Mumbai and production plant in Rajkot, India, combine hot forging, cold forging and CNC machining under one ISO 9001:2015 quality system. Every lot is traceable from the original mill heat to the finished fastener and documented to EN 10204 3.1 as standard, with 3.2 third-party witnessed inspection available on request — so procurement and QA teams receive the paperwork their project specifications demand.
Product Range
Fastener Products We Manufacture
Every product family below is available in all the alloys we process. Specify the dimensional standard, grade and finish — we match the forming route, heat treatment and testing to your application.
Hex Nuts
Hex and heavy hex nuts matched in grade and hardness to the mating bolt or stud to prevent galling.
Standards: ASME B18.2.2, ASTM A194, ISO 4032, DIN 934
View Hex Nuts 
Flat Washers
Plain and through-hardened flat washers that distribute load and protect flange faces in corrosive service.
Standards: ASME B18.21.1 / B18.22.1, ISO 7089, DIN 125
View Flat Washers 
Stud Bolts
Fully threaded, tap-end and double-end studs for ASME B16.5 / B16.47 flange joints in process piping.
Standards: ASTM A193 / A320, ASME B1.1 UNC / 8UN
View Stud Bolts Also manufactured: Socket Cap Screws Threaded Rod Eye Bolts U-Bolts Anchor Bolts Spring & Lock Washers Forged Rings All Products
Material Expertise
Exotic Alloy Fastener Materials
Selecting the wrong alloy is the most common cause of premature bolting failure. Use the overview and selection table below to shortlist a grade, then share your operating temperature, media and pressure class with our engineers for confirmation.
304 · 316L · 17-4 PH
Stainless Steel
Austenitic and precipitation-hardening grades for general corrosion resistance and high-strength applications.
Stainless Fasteners625 · 718 · 825
Inconel & Nickel Alloys
Retain strength at elevated temperatures and resist oxidation, chloride and acid attack.
Inconel Fasteners2205 · 32750 · Zeron 100
Duplex & Super Duplex
Roughly double the yield strength of 316L with excellent pitting and stress-corrosion resistance.
Duplex FastenersGrade 2 · Grade 5
Titanium
High strength-to-weight ratio and near-immunity to seawater corrosion for offshore and aerospace.
Titanium Fasteners90/10 · 70/30
Copper Nickel
Resist seawater corrosion and biofouling in shipbuilding, desalination and cooling systems.
Cu-Ni Fasteners| Alloy | UNS | Common Fastener Specification | Key Property | Typical Application |
|---|---|---|---|---|
| AISI 316L | S31603 | ASTM A193 B8M / A194 8M | Molybdenum-enhanced chloride resistance | Chemical plants, food processing, coastal structures |
| 17-4 PH | S17400 | ASTM A564 Type 630 | High strength via age hardening | Valves, pumps, aerospace hardware |
| Inconel 718 | N07718 | ASTM B637 / API 6A 718 | High strength up to approx. 650 °C | Gas turbines, subsea wellheads |
| Inconel 625 | N06625 | ASTM B446 | Pitting and crevice corrosion resistance | Seawater, flue-gas, chemical processing |
| Hastelloy C276 | N10276 | ASTM B574 | Resistance to strong oxidizers and reducing acids | Scrubbers, pickling lines, chlorine service |
| Monel 400 | N04400 | ASTM F467 / F468 | Resistance to hydrofluoric acid and seawater | Marine hardware, HF alkylation units |
| Duplex 2205 | S32205 / S31803 | ASTM A479 / A276 | PREN approx. 35, high yield strength | Offshore piping, desalination |
| Super Duplex 32750 | S32750 | ASTM A479 / A182 F53 | PREN > 40, superior pitting resistance | Subsea, firewater, seawater injection |
| Titanium Grade 5 | R56400 | ASTM B348 / F467 / F468 | Lightweight with high tensile strength | Aerospace, offshore risers, motorsport |
| Copper Nickel 70/30 | C71500 | ASTM B151 | Seawater and biofouling resistance | Shipbuilding, condensers, heat exchangers |
Values are indicative for preliminary selection. Final grade, condition and hardness must be confirmed against your project specification and design code.
In Demand
Hot Products & Surface Treatments
The grades our international customers request most often, together with the coatings we apply to extend service life, control friction and simplify tightening.
Most Requested Alloy Fasteners
Hard-to-find fasteners that are difficult to source from stock — manufactured to order and shipped to project sites worldwide.
Inconel 718 Fasteners Inconel 625 Fasteners Monel 400 Fasteners Hastelloy C276 Fasteners Duplex 2205 Fasteners Super Duplex 32750 Fasteners Zeron 100 Bolts Titanium Grade 5 Fasteners Copper Nickel Fasteners AISI 316L Stainless Steel Incoloy 825 Fasteners Waspaloy Fasteners
Plating & Coating Options
From sacrificial zinc to low-friction fluoropolymers, each coating is chosen for the environment, galvanic compatibility and torque requirements.
PTFE Fluorocarbon Coating Hot Dip Galvanizing Electro Zinc Plating Dacromet 320 / 500 Nickel Plating Silver Plating Phosphate Coating Zinc Cobalt Plating Mechanical Zinc Pickled & Passivated All Coatings
PTFE FluorocarbonLow, consistent friction for controlled torque; chemical and UV resistant for offshore bolting.
Hot Dip GalvanizingThick sacrificial zinc layer per ASTM A153 / ISO 1461 for structural and outdoor use.
Electro Zinc PlatingThin, bright decorative protection per ASTM F1941 / B633 for indoor and mild environments.
How We Make It
Manufacturing Process & Capabilities
Exotic alloys behave very differently from carbon steel during forming. We select the forming route for each order based on alloy work-hardening behaviour, diameter and quantity, then verify the result with in-house testing.
Cold Forging
High-precision heading for volume production, preserving continuous grain flow for superior fatigue and tensile performance.
Hot Forging
Elevated-temperature forming for large diameters and high-strength nickel and titanium alloys that resist cold working.
CNC Machining
Bar-stock machining for custom geometries, tight tolerances and short runs built to customer drawings.
Testing & Inspection
Mechanical, chemical and dimensional verification on every lot, with results recorded against the mill heat number.
Order-to-Delivery Workflow
Review
Specification and drawing check
Raw Material
Certified bar with mill heat traceability
Forming
Forging or CNC machining
Heat Treatment
Solution annealing or age hardening
Threading
Thread rolling or cutting
Testing
Mechanical, PMI and dimensional
Finish & Pack
Coating, marking, export packing
Trust & Compliance
Quality Assurance & Certification
For critical bolting, documentation is as important as the part itself. Our quality system is built to satisfy EPC contractors, third-party inspectors and end-user QA audits.
ISO 9001:2015Quality management system covering design, manufacture and supply
PED 2014/68/EUPressure Equipment Directive approval by TUV Rheinland
EN 10204 3.1Manufacturer inspection certificate supplied as standard
EN 10204 3.2Third-party witnessed inspection available on request
Tests Available Per Lot
Testing is planned against the governing material specification and any supplementary customer requirements.
- Positive Material Identification (PMI)
- Chemical composition analysis
- Tensile and yield strength
- Hardness testing
- Charpy impact testing
- Intergranular corrosion (IGC)
- Ferrite content for duplex grades
- Salt spray for coated parts
- Dimensional and thread gauging
- NACE MR0175 / ISO 15156 hardness
Applications
Industries We Serve Worldwide
TorqBolt fasteners are installed where corrosion, temperature and pressure leave no margin for error — supplied to customers across India, the Middle East, Europe, North America and Australia.
Oil & Gas
Wellhead, subsea and pipeline flange bolting, including sour-service duty.
Petrochemical & Chemical
Reactors, heat exchangers and acid-handling equipment.
Power Generation
Turbine casings, boilers and high-temperature steam lines.
Nuclear
Documented, fully traceable fasteners for controlled environments.
Marine & Offshore
Seawater-resistant bolting for vessels, platforms and desalination.
Aerospace
Lightweight titanium and nickel superalloy fasteners.
Pulp & Paper
Bleach plant and digester equipment exposed to chlorides.
Water Treatment
Corrosion-resistant fixings for pumps, screens and RO systems.
Buyer's Guide
What to Specify for an Accurate Offer
Incomplete specifications are the main cause of delays in exotic-alloy fastener projects. Sharing these details in your first message lets our engineers confirm feasibility, documentation and lead time without back-and-forth.
- Material grade
- Alloy name or UNS number, e.g. UNS S32750 or N07718
- Dimensional standard
- ASME B18.2.1, ASTM A193, DIN 931, ISO 4014 or drawing
- Size & thread
- Diameter, length, thread pitch (UNC, UNF, 8UN, metric)
- Quantity
- Pieces per size, including spares
- Coating / finish
- PTFE, HDG, zinc, passivated or plain
- Documentation
- EN 10204 3.1 or 3.2, NACE, PED, PMI reports
- Destination
- Delivery country and project site
About TorqBolt Inc.
Since 2010, TorqBolt has focused on one thing: supplying fasteners in materials that most suppliers cannot. Our team works directly with procurement managers, piping engineers and inspection agencies to deliver specification-compliant bolting for critical projects.
FAQ
Frequently Asked Questions
Which exotic alloys does TorqBolt manufacture fasteners in?
We manufacture fasteners in stainless steels (304, 316L, 17-4 PH, 15-5 PH), nickel alloys (Inconel 625 and 718, Incoloy 825, Monel 400, Hastelloy C276 and B2, Waspaloy), Duplex 2205, Super Duplex 32750 and Zeron 100, Titanium Grade 2 and Grade 5, Copper Nickel 90/10 and 70/30, and Aluminium 7075.
What certification documents are supplied with each shipment?
Fasteners are supplied with EN 10204 3.1 mill test certificates as standard, with full heat-number traceability. EN 10204 3.2 certification witnessed by a third-party inspection agency can be arranged on request. We operate under ISO 9001:2015 and are PED 2014/68/EU approved by TUV Rheinland.
Can you manufacture non-standard or drawing-based fasteners?
Yes. In addition to ASME, ASTM, DIN and ISO standard fasteners, we produce custom fasteners to customer drawings using hot forging, cold forging and CNC machining — well suited to low-volume, large-diameter and hard-to-find parts in exotic alloys.
Are your fasteners suitable for sour service under NACE MR0175 / ISO 15156?
Fasteners for sour service can be supplied with hardness control and documentation in line with NACE MR0175 / ISO 15156 requirements. State the sour-service requirement in your enquiry so that material, heat treatment and hardness testing are planned accordingly.
What information should I include when sending an enquiry?
Include the material grade or UNS number, dimensional standard, diameter, thread pitch and length, quantity, coating, required certification (EN 10204 3.1 or 3.2, NACE) and the destination country. See the buyer's guide above for a complete checklist.