Stud Bolts
Manufacturer
& Exporter
What We Mean by “Stud Bolts”
A stud bolt is a headless, externally threaded rod used with two nuts (or a nut and a tapped bore) rather than a single nut and bolt head. Because a stud has no head to react torque against on one side, it distributes clamping force more evenly across the joint, and it’s specifically designed to be loaded in pure axial tension rather than the bending and shear stresses a through-hole hex bolt can be exposed to in a misaligned joint. This is precisely why flange assemblies on pressure piping are specified with stud bolts, not hex bolts.
We manufacture four core stud configurations: fully/continuous threaded studs (threaded end to end), tap-end studs (threaded ends with an unthreaded shank between, one end torqued into a tapped bore), double-end studs (threaded ends with a shorter unthreaded center section, both ends receiving nuts), and reduced shank studs (a smaller-diameter center section for reduced weight and controlled elongation).
Every configuration is available across our full material range — A193 Grade B7/B7M carbon-alloy steel, our B8/B8M/B8T/B8S stainless range, duplex and super duplex, and exotic alloys including Inconel, Monel, and Hastelloy — always supplied matched with the correct ASTM A194 nut grade.
One Supplier, Every Configuration & Material
Full Material Range
From A193 B7 carbon-alloy through to exotic alloys like Inconel and Monel — the correct grade for every flange class and service condition.
All Four Stud Configurations
Continuous thread, tap-end, double-end, and reduced shank — matched to the specific flange or equipment tapping requirement.
Matched Stud & Nut Systems
Grade-matched ASTM A194 nuts supplied with every stud order, so the joint’s metallurgy is consistent end to end.
Custom Lengths & Non-Standard Studs
Drawing-to-part manufacturing for non-catalogue lengths, special thread pitches, and non-standard flange applications.
Stud Bolts vs Hex Bolts — When Does a Flange Actually Need a Stud?
Both fasten two flange faces together, so it’s a fair question why stud bolts are specified at all when a hex bolt is simpler and cheaper. The answer is in how load actually travels through the joint. A stud, torqued from both ends against nuts, loads in pure axial tension. A through-hole hex bolt in a flange can pick up bending stress if the flange faces aren’t perfectly parallel — a real risk on larger or older flanges — and its head geometry limits how evenly it can distribute clamping force across a gasketed joint. This is the comparison we walk through with buyers who default to hex bolts out of habit rather than flange design requirement.
| Property | Stud Bolt (with two nuts) | Hex Bolt (through-hole) |
|---|---|---|
| Load Type | Pure axial tension | Tension, with bending/shear risk if misaligned |
| Clamping Force Distribution | Even, across the full gasket face | Can be uneven at the bolt head bearing point |
| Standard Specification | ASME B16.5 flange bolting | General assembly, not flange-standard |
| Maintenance / Re-torquing | Both nuts accessible, stud stays in place | Full bolt removed and reinserted |
| Typical Use | Pressure piping, process equipment flanges | General structural and machinery assembly |
Stud Bolt Product Range
Continuous / Fully Threaded Studs
Threaded end to end for maximum nut positioning flexibility
Tap-End Stud Bolts
One end torqued directly into a tapped equipment bore
Double-End Stud Bolts
The standard flange configuration — a nut at each end
Reduced Shank Studs
Controlled elongation and reduced weight for specific joints
Stud Bolt Technical Specifications
Available Materials
- Carbon-Alloy Steel A193 B7 / B7M
- Stainless Steel B8 / B8M / B8T / B8S
- Low-Temperature Alloy A320 L7 / L7M
- Duplex / Super Duplex S32205 / S32750
- Exotic Alloys Inconel / Monel / Hastelloy
ASTM A194 Reference
- With A193 B7 A194 Grade 2H
- With A193 B8 A194 Grade 8
- With A193 B8M A194 Grade 8M
- With A193 B8T A194 Grade 8T
- With A193 B8S A194 Grade 8S
Available Dimensions
- Metric Diameter M6 – M100
- Imperial Diameter 1/4″ – 4″
- Length Custom to flange/drawing spec
- Thread Type UNC / UNF / Metric
- Testing MTC / NABL on request
Application Areas
Wherever a flange joint needs to hold pressure reliably, not just hold two plates together.
Oil & Gas Flange Assemblies
flange bolting
Power Generation Piping
and process line fastening
Chemical Processing
flange fastening
Marine & Offshore
flange bolting for harsh service
Structural & Heavy Engineering
heavy machinery assembly
General Industrial Equipment
across every material grade
Cryogenic & Low-Temperature
for sub-zero service
Water & Desalination Plants
process flange fastening
Standard Export Documentation
Prepared as standard practice for every stud bolt shipment, regardless of configuration or material.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification.
Certificate of Conformance
Confirms the shipment matches the purchase order specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown.
NABL Accredited Test Reports
Independent mechanical and chemical testing available on request.
Bill of Lading
Ocean or air freight shipping document confirming carrier, mode, and consignee details.
Internationally Recognised Standards Coverage
Related Products & Materials
Bolts
Hex, Allen, flange, carriage, and every other head type for general assembly.
View Bolts →Nuts
ASTM A194 heavy hex nuts, matched to every stud grade we manufacture.
View Nuts →ASTM A193 Grade B8T Fasteners
Titanium-stabilized stud bolts, built for high-temperature weld-adjacent service.
View Grade B8T →ASTM A193 Grade B8S Fasteners
Nitrogen-strengthened stud bolts for high-strength, anti-galling service.
View Grade B8S →Sourcing Stud Bolts
for Your Flange?
Configuration · size · material · quantity. Akbar Fasteners Pvt. Ltd. responds within 24 hours with pricing and mill test documentation.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · export@akbarfasteners.in