Stainless Steel Stud Bolts Manufacturer & Exporter in India
M6 to M100 | ASTM A193 B8, B8M, B8T | EN 10204 3.1 certificate on every consignment | dispatch in 5-10 working days
Unifit Fastener manufactures stainless steel stud bolts in India for oil and gas, power generation, chemical processing, marine and construction service. We produce in SS 304, 304L, 316, 316L, 321, 347, 310 and 310S, to property classes A2-70 and A4-80 under ISO 3506-1 and to ASTM A193 Grades B8, B8M and B8T with matching A194 nuts.
Studs are supplied double-end, tap-end and fully threaded, from M6 to M100 (1/4" to 4"), in lengths to 500 mm, threaded to DIN 975 / 976 and ASME B18.31.2 / B18.31.3. Threads are rolled rather than cut wherever the geometry allows - a rolled root carries materially more fatigue life on a flange that cycles.
Every heat is PMI-verified on arrival. Every consignment ships with an EN 10204 3.1 mill test certificate and NABL-accredited laboratory reports, with heat-number traceability from the mill certificate to the marked stud. Third-party inspection from Lloyd's, BV, SGS, TUV and IBR is accepted.
providing reliable performance in extreme temperatures and highly corrosive environments.
Available in sizes from M3 to M100 (1/4" to 4"), our stainless steel stud bolts are available as double end, fully threaded and tap end models and come in custom lengths, coatings and finishes to suit your needs. Underpinned by in-house quality testing, NABL (National Accreditation Board for Testing and Calibration Laboratories) certified laboratory reports and Material Test Certificate (MTC) in accordance with EN 10204 3.1/3.2, Unifit Fastener provides fasteners that can be trusted in critical flanged connections, pressure vessels, heavy equipment, etc. From trial orders to export volumes, we provide engineers and procurement teams with competitive pricing, quick turnaround and end-to-end technical support to make us their choice fastener provider in India and across the globe.
Request a QuoteTable of content
- What Are Stainless Steel Stud Bolts?
- Our SS Stud Bolt Grades
- SS Stud Bolt Specification
- Mechanical Properties (ASTM A193 / A194)
- Chemical Composition (Typical, % by weight)
- Stainless Steel Stud Bolts Sizes
- Stainless Steel Stud Bolt Types
- Torque Chart for Double End Stainless Steel Stud Bolts
- Physical Properties of Stainless Steel Stud Bolts
- Stainless Steel Stud Bolts vs. Alloy Steel / Inconel Stud Bolts
- Manufacturing Process & Quality Control
- Certifications & Standards
- Stainless Steel Stud Bolts Price List
What Are Stainless Steel Stud Bolts?
A stainless steel stud bolt is a fully or partially threaded rod, threaded on both ends (double-end) or entirely (fully threaded), used with nuts and washers to join flanges, valves, and equipment. Manufactured from corrosion-resistant stainless steel alloys, these stud bolts withstand extreme pressure, temperature swings, and aggressive chemical exposure far better than standard carbon steel fasteners.
Our SS Stud Bolt Grades
SS Stud Bolt Specification
| Attribute | Specification |
|---|---|
| Material Grades | Stainless Steel 304, 304L, 316, 316L, 321, 347, 310, 310S |
| Property Class | A2-50, A2-70, A4-70, A4-80 (ISO 3506-1) |
| Size Range | M3 - M100 / 1/4" - 4" |
| Length Range | 6 mm - 500 mm (Custom lengths available) |
| Standards | ASTM A193, ASTM A194, ASME B18.31.2, DIN 975, DIN 976, ISO 261, ISO 965 |
| Stud Types | Double-End Studs, Fully Threaded Studs, Tap-End Studs, Continuous Thread Studs |
| Thread Type | Metric Coarse & Fine, UNC, UNF, BSW, BSF |
| Surface Finish | Plain, Passivated, Black Oxide, Zinc Plated, PTFE Coated, Xylan Coated, Cadmium Plated* |
| Production Method | Cold Forging, Hot Forging, CNC Machining |
| Certification | EN 10204 3.1 / 3.2 Mill Test Certificate (MTC), PMI Test Report, NABL-Approved Test Reports |
Mechanical Properties (ASTM A193 / A194)
| Grade | Material | Class | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation (%) |
|---|---|---|---|---|---|
| B8 | AISI 304 | Class 1 | 75 | 30 | 30 |
| B8M | AISI 316 | Class 1 | 75 | 30 | 30 |
| B8T | AISI 321 | Class 1 | 75 | 30 | 30 |
| B8 Strain Hardened | AISI 304 | Class 2 | 100-125 | 50-100 | 12-28 |
| B8M Strain Hardened | AISI 316 | Class 2B/2C | 75-95 | 50-65 | 25-60 |
Chemical Composition (Typical, % by weight)
| Grade | Chromium | Nickel | Molybdenum | Carbon (max) |
|---|---|---|---|---|
| SS 304 | 18.00-20.00 | 8.00-10.50 | - | 0.08 |
| SS 304L | 18.00-20.00 | 8.00-12.00 | - | 0.03 |
| SS 316 | 16.00-18.00 | 10.00-14.00 | 2.00-3.00 | 0.08 |
| SS 316L | 16.00-18.00 | 10.00-14.00 | 2.00-3.00 | 0.03 |
| SS 321 | 17.00-19.00 | 9.00-12.00 | - | 0.08 |
Stainless Steel Stud Bolts Sizes
| Diameter | Diameter (inch) | Diameter (mm) | Standard Nut Size |
|---|---|---|---|
| M10 | 0.3937 | 10 | 17 |
| M12 | 0.4724 | 12 | 19 |
| M16 | 0.6299 | 16 | 24 |
| M20 | 0.7874 | 20 | 30 |
| M24 | 0.9449 | 24 | 36 |
| M30 | 1.1811 | 30 | 46 |
| M36 | 1.4173 | 36 | 55 |
Stainless Steel Stud Bolt Types
SS Stud Bolt
Stainless Steel Wheel Stud Bolts
Double End Stainless Steel Stud Bolts
Fully Threaded Stud Bolts
SS Flange Stud Bolts
SS Tap End Stud Bolts
Stainless Stud Anchor Bolts
SS Stud Bolts And Nuts
SS Welding Studs
Torque Chart for Double End Stainless Steel Stud Bolts
| Nominal Pipe Size (NPS) | Stud Bolt Sequence | Stud Bolt Size | 1st Pass | 2nd Pass | Final Pass |
|---|---|---|---|---|---|
| 1/2" | 4-Bolt | 1/2" | 30% of Final Torque | 60% of Final Torque | 100% of Specified Torque |
| 3/4" | 4-Bolt | 1/2" | 30% | 60% | 100% |
| 1" | 4-Bolt | 1/2" | 30% | 60% | 100% |
| 1-1/4" | 4-Bolt | 1/2" | 30% | 60% | 100% |
| 1-1/2" | 4-Bolt | 1/2" | 30% | 60% | 100% |
| 2" | 4-Bolt | 5/8" | 30% | 60% | 100% |
| 2-1/2" | 4-Bolt | 5/8" | 30% | 60% | 100% |
| 3" | 4-Bolt | 5/8" | 30% | 60% | 100% |
| 3-1/2" | 8-Bolt | 5/8" | 30% | 60% | 100% |
| 4" | 8-Bolt | 5/8" | 30% | 60% | 100% |
| 5" | 8-Bolt | 3/4" | 30% | 60% | 100% |
| 6" | 8-Bolt | 3/4" | 30% | 60% | 100% |
| 8" | 8-Bolt | 3/4" | 30% | 60% | 100% |
| 10" | 12-Bolt | 7/8" | 30% | 60% | 100% |
| 12" | 12-Bolt | 7/8" | 30% | 60% | 100% |
| 14" | 12-Bolt | 1" | 30% | 60% | 100% |
| 16" | 16-Bolt | 1" | 30% | 60% | 100% |
| 18" | 16-Bolt | 1-1/8" | 30% | 60% | 100% |
| 20" | 20-Bolt | 1-1/8" | 30% | 60% | 100% |
| 24" | 20-Bolt | 1-1/4" | 30% | 60% | 100% |
Physical Properties of Stainless Steel Stud Bolts
| Grades | Density (g/cm3) | Melting Point ( C) | Electrical Resistivity (uohm-cm) | Thermal Conductivity (W/m-K) | Coefficient of Thermal Expansion (um/m- C) |
|---|---|---|---|---|---|
| SS 304 | 7.93 | 1400 - 1450 | 72.3 | 16.2 | 16.0 |
| SS 304L | 7.93 | 1400 - 1450 | 72.3 | 16.2 | 16.0 |
| SS 304H | 7.93 | 1400 - 1450 | 72.3 | 16.2 | 16.0 |
| SS 310 | 7.90 | 1400 - 1450 | 72.0 | 14.0 | 17.0 |
| SS 310S | 7.90 | 1400 - 1450 | 72.0 | 14.0 | 17.0 |
| SS 316 | 7.98 | 1375 - 1400 | 74.0 | 16.3 | 16.5 |
| SS 316L | 7.98 | 1375 - 1400 | 74.0 | 16.3 | 16.5 |
| SS 316Ti | 7.98 | 1375 - 1400 | 74.0 | 16.3 | 16.5 |
| SS 317 | 7.95 | 1375 - 1400 | 74.5 | 16.3 | 16.5 |
| SS 317L | 7.95 | 1375 - 1400 | 74.5 | 16.3 | 16.5 |
| SS 321 | 7.93 | 1400 - 1450 | 74.0 | 16.2 | 16.0 |
| SS 321H | 7.93 | 1400 - 1450 | 74.0 | 16.2 | 16.0 |
| SS 347 | 7.93 | 1400 - 1450 | 74.0 | 16.2 | 16.0 |
| SS 410 | 7.75 | 1480 - 1530 | 78.0 | 30.0 | 11.5 |
| SS 446 | 7.80 | 1400 - 1450 | 76.0 | 30.0 | 11.5 |
| SS 904L | 8.00 | 1350 - 1400 | 70.0 | 15.0 | 16.0 |
Stainless Steel Stud Bolts vs. Alloy Steel / Inconel Stud Bolts
| Property | Stainless Steel Stud Bolts | Carbon/Alloy Steel Stud Bolts | Inconel Stud Bolts |
|---|---|---|---|
| Corrosion Resistance | Very Good | Poor (needs coating) | Excellent |
| Max Service Temperature | Up to 870 C (grade dependent) | Up to ~450 C | Up to 1100 C |
| Relative Cost | Moderate | Low | High |
| Typical Use Case | Process piping, food, marine, pressure vessels | General construction, structural | Aerospace, extreme chemical/thermal duty |
Manufacturing Process & Quality Control
- Raw material sourcing & chemical verification
- Wire drawing and cold/hot heading
- Thread rolling / CNC machining
- Heat treatment for mechanical properties
- Surface treatment: passivation, plating, or coating
- 100% dimensional inspection
- Batch-wise mechanical testing (tensile, hardness, elongation)
- Final packing with traceable batch documentation
Certifications & Standards
- ISO 9001:2015 Certified Manufacturing
- Material Test Certificate as per EN 10204 3.1 / 3.2
- Compliance with ASTM A193 / A194, ASME B18.31.3
- DIN 931 / 933 / 975 / 976 Standards
- NABL-Approved Laboratory Test Reports
- RoHS & REACH Compliant Materials on Request
Stainless Steel Stud Bolts Price List
| Material Grade | Size Range | Approx. Price (USD/Piece)* | Approx. Price (USD/Kg)* | Approx. Price (INR/Kg)* | Typical Applications |
|---|---|---|---|---|---|
| SS 304 Stud Bolts | M6-M100 | $0.30 - $25.00 | $2.50 - $4.50 | INR 220 - INR 380 | General engineering, construction, food processing |
| SS 304L Stud Bolts | M6-M100 | $0.35 - $28.00 | $2.80 - $4.80 | INR 240 - INR 400 | Welded structures, chemical processing |
| SS 316 Stud Bolts | M6-M100 | $0.50 - $40.00 | $4.00 - $6.50 | INR 350 - INR 550 | Marine, chemical, offshore, pharmaceutical |
| SS 316L Stud Bolts | M6-M100 | $0.55 - $42.00 | $4.20 - $6.80 | INR 360 - INR 580 | Corrosive process plants, marine, food processing |
| SS 310/310S Stud Bolts | M6-M100 | $1.20 - $70.00 | $7.00 - $12.00 | INR 600 - INR 1,000 | High-temperature furnaces, heat treatment equipment |
| SS 321 Stud Bolts | M6-M100 | $0.90 - $50.00 | $5.50 - $8.50 | INR 470 - INR 720 | Aerospace, exhaust systems, high-temperature piping |
| SS 347 Stud Bolts | M6-M100 | $1.00 - $55.00 | $6.00 - $9.50 | INR 500 - INR 800 | Refineries, power plants, pressure vessels |
| SS 904L Stud Bolts | M6-M100 | $2.50 - $150.00 | $12.00 - $22.00 | INR 1,000 - INR 1,900 | Acid processing, desalination, offshore, pulp & paper |