High-Performance Stainless Steel Fasteners for Global Industries
Neelkamal Alloys LLP is a globally recognized manufacturer, stockist, and exporter of high-integrity Stainless Steel Fasteners located in Mumbai, India. We produce a full range of precision-engineered industrial bolting solutions including hex bolts, heavy hex nuts, stud bolts, socket cap screws, washers, and custom drawing components.
Engineered for harsh environments across oil & gas, chemical processing, marine engineering, power generation, and heavy construction, our stainless steel fasteners offer exceptional tensile strength, elevated heat tolerance, and superior resistance to pitting, crevice corrosion, and atmospheric oxidation.
Every shipment is backed by 100% material traceability, positive material identification (PMI) testing, dimensional verification to ASME, DIN, and ISO standards, and EN 10204 3.1 Mill Test Certificates.
Stainless Steel Fasteners Material Grades & Standards
Detailed technical specification overview for procurement managers, piping engineers, and quality assurance teams.
| Parameter | Technical Details & Options |
|---|---|
| Standard Specifications | ASTM A193, ASTM A194, ASTM A320, ASTM F593, ASME B18.2.1, ASME B18.2.2, DIN 931, DIN 933, DIN 934, DIN 912, ISO 4014, ISO 4017, ISO 4032, BS, UNI, CSN, PN |
| ASTM Material Specifications | ASTM A193 Grade B8 (304), B8M (316), B6 (410), B8T (321), B8C (347); ASTM A194 Grade 8, 8M, 8C, 8T; ASTM A320 Grade B8 Class 1 & Class 2 |
| Austenitic SS Grades | Stainless Steel 304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 317L, 321, 321H, 347, 347H |
| Martensitic & Ferritic Grades | Stainless Steel 410, 420, 422, 430, 446, 202 |
| Property Classes / Strengths | A2-50, A2-70, A2-80, A4-50, A4-70, A4-80, B8 Class 1, B8 Class 2, B8M Class 1, B8M Class 2 |
| Size Range | Metric: M1.6 to M100 | Imperial: 3/16" to 4" (Custom non-standard lengths up to 3000mm) |
| Thread Profiles | UNC, UNF, UNEF, Metric Coarse, Metric Fine, BSW, BSF, NPT, Acem Thread |
| Surface Coatings & Finishes | Passivated, Electropolished, Plain/Bright Finish, Hot-Dip Galvanized (HDG), Black Oxide (F593C), PTFE/Teflon Coated, Zinc Plated, Cadmium Plated |
| Quality Assurance & MTC | EN 10204 3.1 Certified, NDT Inspection, PMI Test, Tensile & Hardness Test Report, Third Party Inspection (TUV, BV, SGS, DNV, Lloyd's) |
Complete Stainless Steel Fasteners Product Range
Precision-manufactured components designed for flawless fitment and long-term joint integrity.
Stainless Steel Bolts
Hexagon Head Bolts, Heavy Hex Bolts, Allen Socket Head Cap Screws, Carriage Bolts, U-Bolts, Eye Bolts, L-Bolts, Foundation Bolts, Dome Head Bolts, T-Head Bolts, Stripper Shoulder Bolts.
Stainless Steel Stud Bolts & Rods
Fully Threaded Stud Bolts (ASTM A193 B8/B8M), Tap End Studs, Double-End Stud Bolts, Threaded Bars / Rods (DIN 975 / DIN 976), Tie Rods for pressure vessel flanges and high-temperature piping.
Stainless Steel Nuts
Hex Nuts, Heavy Hex Nuts (ASTM A194 Gr 8/8M), Lock Nuts (Nylon Insert & All-Metal), Hex Thin Nuts (Jam Nuts), Flange Nuts, Dome Cap Nuts, Slotted Castle Nuts, Square Nuts.
Stainless Steel Screws
Socket Cap Screws, Button Head Screws, Countersunk Screws, Machine Screws (M1.6 to M12), Self-Tapping Screws, Wood Screws, Grub Set Screws with cup/flat/cone point.
Stainless Steel Washers
Flat Plain Washers (DIN 125A / ISO 7089), Spring Lock Washers (DIN 127B), Square Section Lock Washers (DIN 7980), Heavy-Duty Belleville Washers, Fender Washers, Curved Washers.
Special & Custom Fasteners
Machined components based on client CAD drawings, shear connector studs, dowel pins, rivets, non-standard pitch thread bolting, and custom-coated corrosion barrier fasteners.
Stainless Steel Fasteners Metric Dimension Chart
Standard dimensioning reference and DIN / ISO equivalencies for standard metric fasteners.
| Fastener Type | Standard Sizes | Property Classes | Dimensional Standards |
|---|---|---|---|
| Socket Head Cap Screw | M3 to M30 | A2-70, A2-80, A4-70, A4-80 | DIN 912 / ISO 4762 / ASME B18.3 |
| Hex Head Screw (Full Thread) | M3 to M56 | A2-70, A2-80, A4-70, A4-80 | DIN 933 / ISO 4017 / ASME B18.2.1 |
| Hex Head Bolt (Partial Thread) | M4 to M100 | A2-70, A2-80, A4-70, A4-80 | DIN 931 / ISO 4014 / ASME B18.2.1 |
| Heavy Hex Nut / Standard Nut | M3 to M100 | A2-70, A2-80, A4-70, A4-80, Gr 8, Gr 8M | DIN 934 / ISO 4032 / ASME B18.2.2 |
| Plain Flat Washer | M3 to M64 | A2 (304), A4 (316) | DIN 125 A / ISO 7089 |
| Flat-Section Spring Washer | M3 to M36 | A2 (304), A4 (316) | DIN 127 B |
| Square-Section Spring Washer | M3 to M36 | A2 (304), A4 (316) | DIN 7980 |
| All-Thread Stud Rod | M3 to M56 | A2-70, A2-80, A4-70, A4-80, B8, B8M | DIN 975 / DIN 976 / ASME B18.31.2 |
Stainless Steel Bolts Tightening Torque Specification Chart
Recommended standard dry torque values in Inch-Pounds for Grade 304 and 316 stainless steel bolts to prevent thread galling and ensure optimum joint clamping pressure.
| Bolt Size (Inches / #) | Threads Per Inch (TPI) | Grade 304 Dry Torque (in-lbs) | Grade 316 Dry Torque (in-lbs) |
|---|---|---|---|
| #2 | 56 / 64 | 2.05 - 3.00 | 2.06 - 3.02 |
| #3 | 48 / 56 | 3.09 - 4.04 | 4.00 - 4.06 |
| #6 | 32 / 40 | 9.06 - 12.01 | 10.01 - 12.07 |
| #8 | 32 / 36 | 19.08 - 22.00 | 20.07 - 23.00 |
| #10 | 24 / 32 | 22.08 - 31.07 | 23.08 - 33.01 |
| 1/4" | 20 / 28 | 75.00 - 94.00 | 78.00 - 99.00 |
| 5/16" | 18 / 24 | 132.0 - 142.0 | 138.0 - 147.0 |
| 3/8" | 16 / 24 | 236.0 - 259.0 | 247.0 - 271.0 |
| 1/2" | 13 / 20 | 517.0 - 541.0 | 542.0 - 565.0 |
| 9/16" | 12 / 18 | 682.0 - 752.0 | 713.0 - 787.0 |
| 5/8" | 11 / 18 | 1,110 - 1,240 | 1,160 - 1,300 |
| 3/4" | 10 / 16 | 1,530 - 1,700 | 1,600 - 1,780 |
| 7/8" | 9 / 14 | 2,328 - 2,318 | 2,430 - 2,420 |
| 1" | 8 / 14 | 3,440 - 3,110 | 3,595 - 3,250 |
| 1-1/4" | 7 / 12 | 5,230 - 4,800 | 5,460 - 5,040 |
Why Oversea Procurement Teams Choose Neelkamal Alloys LLP
We combine strict metallurgical controls, precision thread-rolling technology, and rigorous non-destructive testing to fulfill complex project requirements with zero defects.
- 100% Raw Material Chemical Heat Analysis Verification
- Positive Material Identification (PMI) on 100% of Exotic & SS Orders
- Dimensional & Thread Pitch Gauge Checks to ASME / DIN Standards
- Tensile, Yield, Hardness & Proof Load Mechanical Testing
- Intergranular Corrosion (IGC) Test per ASTM A262 Practice E
- EN 10204 3.1 Mill Test Certificates Provided With Every Order
- Third-Party Inspection Accepted (TUV, Bureau Veritas, SGS, DNV)
- Seaworthy Heavy Duty Export Packaging (Wooden Boxes & Shrink Wrapped)
Export Markets & Destination Network
Neelkamal Alloys LLP regularly supplies stainless steel fasteners to major EPC contractors, plant operators, stockists, and OEMs across 105+ countries.