Stainless Steel 321 Fasteners Manufacturer, Supplier & Exporter in India
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Aashish Metal & Alloys is one of the well-known manufacturers, stockists and exporters of Stainless Steel 321 fasteners which provide the high-performance fastening solutions to industries where heat and corrosion never take a break. Grade 321 is a titanium-stabilized austenitic stainless steel and this one addition of titanium is the differentiator: it will bind up carbon before it can bond to chromium and form chromium carbides, preventing the fasteners from intergranular corrosion following welding or extended exposure to high temperatures. The outcome is a bolt, nut or stud that resists sensitisation across the 425–815 °C range and gives reliable oxidation service to ~870 °C, where most 304 metals suffer a drop in their properties. We make the entire range of metric and imperial sizes of hex bolts, heavy hex bolts, stud bolts, U bolts, eye bolts, hex nuts, washers, and custom screws, all backed by mill test certificates EN 10204 3.1, backed up on request by a third party inspection service, and traceable. Your project stays on time and on spec whether you need a single critical stud for a heat exchanger or tonnage for a refinery shutdown, our ready stock, custom manufacturing and global logistics are helping you keep your project moving.
Table of Content
- What Are Stainless Steel 321 Fasteners?
- SS 321 vs SS 321H – Know the Difference
- Our SS 321 Fastener Product Range
- Stainless Steel 321 Fasteners Standards
- Stainless Steel 321 Bolts Dimensions
- 321 SS Fasteners Weight Chart
- Stainless Steel 321 Fasteners Price List
- Technical Specifications
- Chemical Composition of Stainless Steel 321 Fastener
- Mechanical Properties of Stainless Steel 321 Fasteners
- Physical Properties of Stainless Steel 321 Fasteners
- Equivalent Grades of Stainless Steel 321 Fasteners
- Stainless Steel 321 Fasteners Applications
- SS 321 vs SS 304 vs SS 347 Comparison
- Manufacturing, Testing & Quality Assurance
- Certifications & Standards
- Related Products
- Frequently Asked Questions
What Are Stainless Steel 321 Fasteners?
Stainless Steel 321 fasteners are fastening components — bolts, nuts, studs, screws, and washers — manufactured from grade 321 austenitic stainless steel (UNS S32100, Werkstoff 1.4541). The alloy contains roughly 17–19% chromium and 9–12% nickel, plus a deliberate addition of titanium at five times the carbon content. This titanium stabilization is the defining feature: during welding or service in the 425–815 °C sensitisation range, titanium combines with carbon to form titanium carbides, preventing the chromium-carbide precipitation (“sensitization”) that would otherwise leave the metal vulnerable to intergranular attack.
In practical terms, that means SS 321 fasteners can be welded, heated, and cooled repeatedly without losing their corrosion resistance — a property that ordinary 304 fasteners cannot guarantee. They are non-magnetic in the annealed condition, offer excellent oxidation resistance, good creep strength, and reliable performance in moderately and highly oxidizing environments.
321 vs 321H — Know the Difference
Grade 321 carries up to 0.08% carbon and is the general-purpose choice. Grade 321H is the high-carbon variant (0.04–0.10% C) developed for sustained creep strength above 537 °C, making it the preferred specification for boiler, superheater, and high-temperature pressure applications.
Our SS 321 Fastener Product Range
We manufacture and stock the full family of grade 321 fasteners so you can source every component from a single, traceable supplier.
- Bolts: Hex bolts, heavy hex bolts, full-threaded bolts, carriage bolts, eye bolts, U-bolts, J-bolts, hook bolts, socket head cap screws, countersunk bolts, flange head bolts, Allen bolts, 12-point flange bolts, shoulder bolts, anchor bolts, and lag bolts.
- Nuts: Hex nuts, heavy hex nuts, square nuts, nyloc (nylon insert) nuts, dome/acorn nuts, T-nuts, sleeve nuts, lock nuts, castle nuts, 12-point nuts, rivet nuts, and coupling nuts.
- Studs & Threaded Rod: Double-end stud bolts, fully threaded studs, tap-end studs, ASME SA193 threaded rod, and left/right-hand threaded rod.
- Washers: Plain (flat) washers, spring/lock washers, split washers, tab washers, sealing washers, square washers, and star washers.
- Screws: Machine screws, self-tapping screws, self-drilling screws, torx screws, grub screws, wood screws, and roofing screws.
Stainless Steel 321 Fasteners Standard
| Hexagon Bolt / Set Screws | Stud Bolt | Hexagon Nuts | Socket Cap screws |
|---|---|---|---|
| DIN 931 | BS4882 | DIN 934 | DIN 912 |
| DIN 933 | DIN 976 | BS 1768 | DIN 6912 |
| BS 1768 | BS 1769 | DIN 7984 | |
| UNI 5731 | BS 1083 | ANSI B18.3 | |
| UNI 5739 | BS 3692 | ISO 4762 | |
| ISO 4014 | ISO 4032 | UNI 5931 | |
| ISO 4017 | ISO 4033 | BS 2470 | |
| BS 1769 | ANSI B18.2.2 | BS 4168 | |
| BS 3692 | |||
| ANSI B18.2.1 | |||
| Socket & Slotted Set Screws | Socket & Slotted Countersunk Screws | Studs | Washers |
| DIN 913 | DIN 963 | DIN 938 | DIN 125 |
| DIN 914 | DIN 7991 | DIN 939 | DIN 9021 |
| DIN 915 | BS 4168 | DIN 2510 | BS 4320 |
| DIN 916 | BS 1981 | BS 4439 | BS 3410 |
| DIN 551 | BS 483 | BS 2693 | |
| DIN 553 | BS 2470 | Spring Washers | |
| DIN 438 | DIN 127 | ||
| BS 4168 | BS 4464 | ||
| BS 1802 |
ANSI and/or ASME Standards Fasteners(inch series)
| ASME B18.1.1 | Small Solid Rivets | ASME B18.8.1 | Clevis Pins and Cotter Pins |
|---|---|---|---|
| ASME B18.1.2 | Large Rivets | ASME B18.8.2 | Taper Pins, Dowel Pins, Straight Pins, Grooved Pins and Spring Pins |
| ASME B18.2.1 | Square and Hex Bolts and Screws | ASME B18.9 | Plow Bolts |
| ASME B18.2.2 | Square and Hex Nuts | ASME B18.10 | Track Bolts and Nuts |
| ASME B18.2.6 | Fasteners for use in Structural Applications | ASME B18.11 | Miniature Screws |
| ASME B18.3 | Socket Cap, Shoulder and Set Screws | ASME B18.13 | Screws and Washer Assemblies (Sems) |
| ASME B18.5 | Round Head Bolts | ASME B18.15 | Forged Eyebolts |
| ASME B18.6.2 | Slotted Head Cap Screws, Square Head Set Screws, and Slotted Headless Set Screws | ASME B18.17 | Wing Nuts, Thumb Screws and Wing Screws |
| ASME B18.6.3 | Machine Screws and Machine Screws Nuts | ASME B18.21.1 | Lock Washers |
| ASME B18.6.4 | Thread Forming and Thread Cutting Tapping Screws and Metallic Drive Screws | ASME B18.22.1 | Plain Washers |
| ASME B18.7 | General Purpose Semi- Tubular Rivets, Full Tubular Rivets, Split Rivets and Rivet Caps | ASME B18.23.1 | Beveled Washers |
Stainless Steel 321 Bolts Dimensions
| BOLT DIMENSIONS | ||||||||
|---|---|---|---|---|---|---|---|---|
| Bolt Size | A (max) | B | C (min) | D | E | F Thread Length for Bolt Length | ||
| max | min | 6″ and shorter | over 6″ | |||||
| 1/4″ | 0.260 | 7/16 | 0.484 | 11/64 | 0.03 | 0.01 | 0.750 | 1.000 |
| 5/16″ | 0.324 | 1/2 | 0.552 | 7/32 | 0.03 | 0.01 | 0.875 | 1.125 |
| 3/8″ | 0.388 | 9/16 | 0.620 | 1/4 | 0.03 | 0.01 | 1.000 | 1.250 |
| 7/16″ | 0.452 | 5/8 | 0.687 | 19/64 | 0.03 | 0.01 | 1.125 | 1.375 |
| 1/2″ | 0.515 | 3/4 | 0.826 | 11/32 | 0.03 | 0.01 | 1.250 | 1.500 |
| 5/8″ | 0.642 | 15/16 | 1.033 | 27/64 | 0.06 | 0.02 | 1.500 | 1.750 |
| 3/4″ | 0.768 | 1-1/8 | 1.240 | 1/2 | 0.06 | 0.02 | 1.750 | 2.000 |
| 7/8″ | 0.895 | 1-5/16 | 1.447 | 37/64 | 0.06 | 0.02 | 2.000 | 2.250 |
| 1″ | 1.022 | 1-1/2 | 1.653 | 43/64 | 0.09 | 0.03 | 2.250 | 2.500 |
| 1-1/8″ | 1.149 | 1-11/16 | 1.859 | 3/4 | 0.09 | 0.03 | 2.500 | 2.750 |
| 1-1/4″ | 1.277 | 1-7/8 | 2.066 | 27/32 | 0.09 | 0.03 | 2.750 | 3.000 |
| 1-3/8″ | 1.404 | 2-1/16 | 2.273 | 29/32 | 0.09 | 0.03 | 3.000 | 3.250 |
| 1-1/2″ | 1.531 | 2-1/4 | 2.480 | 1 | 0.09 | 0.03 | 3.250 | 3.500 |
| 1-3/4″ | 1.785 | 2-5/8 | 2.893 | 1-5/32 | 0.12 | 0.04 | 3.750 | 4.000 |
| 2″ | 2.039 | 3 | 3.306 | 1-11/32 | 0.12 | 0.04 | 4.250 | 4.500 |
| 2-1/4″ | 2.305 | 3-3/8 | 3.719 | 1-1/2 | 0.19 | 0.06 | 4.750 | 5.000 |
| 2-1/2″ | 2.559 | 3-3/4 | 4.133 | 1-21/32 | 0.19 | 0.06 | 5.250 | 5.500 |
| 2-3/4″ | 2.837 | 4-1/8 | 4.546 | 1-13/16 | 0.19 | 0.06 | 5.750 | 6.000 |
| 3″ | 3.081 | 4-1/2 | 4.959 | 2 | 0.19 | 0.06 | 6.250 | 6.500 |
| 3-1/4″ | 3.335 | 4-7/8 | 5.372 | 2-3/16 | 0.19 | 0.06 | 6.750 | 7.000 |
| 3-1/2″ | 3.589 | 5-1/4 | 5.786 | 2-5/16 | 0.19 | 0.06 | 7.250 | 7.500 |
| 3-3/4″ | 3.858 | 5-5/8 | 6.198 | 2-1/2 | 0.19 | 0.06 | 7.750 | 8.000 |
| 4″ | 4.111 | 6 | 6.612 | 2-11/16 | 0.19 | 0.06 | 8.250 | 8.500 |
321 SS Fasteners Weight Chart
| Diameter | M12 | M16 | M20 | M22 | M24 | M27 | M30 | M36 |
|---|---|---|---|---|---|---|---|---|
| Length | ||||||||
| 30 | 49.1 | |||||||
| 35 | 53.6 | |||||||
| 40 | 58.0 | 105 | ||||||
| 45 | 62.1 | 113 | 188 | |||||
| 50 | 66.6 | 121 | 200 | 257 | ||||
| 55 | 71.0 | 129 | 212 | 272 | ||||
| 60 | 75.4 | 137 | 225 | 286 | 362 | |||
| 65 | 79.9 | 145 | 237 | 301 | 380 | |||
| 70 | 84.3 | 153 | 249 | 316 | 398 | 532 | ||
| 75 | 88.8 | 160 | 262 | 331 | 415 | 554 | 701 | |
| 80 | 93.2 | 168 | 274 | 346 | 433 | 576 | 728 | |
| 85 | 97.6 | 176 | 286 | 361 | 451 | 599 | 756 | 1184 |
| 90 | 102 | 184 | 298 | 375 | 467 | 621 | 784 | 1224 |
| 95 | 107 | 192 | 310 | 390 | 485 | 644 | 812 | 1264 |
| 100 | 199 | 322 | 405 | 503 | 665 | 838 | 1304 | |
| 105 | 207 | 335 | 420 | 520 | 688 | 865 | 1336 | |
| 110 | 215 | 347 | 435 | 538 | 710 | 893 | 1376 | |
| 115 | 223 | 359 | 450 | 556 | 732 | 921 | 1415 | |
| 120 | 231 | 372 | 465 | 574 | 755 | 949 | 1455 | |
| 125 | 239 | 384 | 479 | 591 | 777 | 976 | 1495 | |
| 130 | 247 | 396 | 494 | 609 | 800 | 1004 | 1535 | |
| 135 | 409 | 509 | 627 | 822 | 1032 | 1575 | ||
| 140 | 421 | 524 | 645 | 845 | 1059 | 1615 | ||
| 145 | 433 | 539 | 662 | 867 | 1087 | 1655 | ||
| 150 | 446 | 554 | 680 | 890 | 1115 | 1695 | ||
| 155 | 458 | 569 | 698 | 912 | 1143 | 1735 | ||
| 160 | 584 | 716 | 935 | 1170 | 1775 | |||
| 165 | 599 | 733 | 957 | 1198 | 1815 | |||
| 170 | 751 | 979 | 1226 | 1855 | ||||
| 175 | 769 | 1002 | 1254 | 1895 | ||||
| 180 | 787 | 1024 | 1281 | 1935 | ||||
| 185 | 804 | 1047 | 1309 | 1974 | ||||
| 190 | 822 | 1069 | 1337 | 2014 | ||||
| 195 | 840 | 1092 | 1365 | 2054 | ||||
| 200 | 1114 | 1392 | 2094 |
For Stainless Steel 321 Fasteners price list
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We Keep Bulk Stock Of 321 Stainless Steel Bolts, Screws At Our Stockyard, Contact Us For Free Sample & Stock List.
Standards & Specifications of Stainless Steel 321 Fasteners
| Parameter | Detail |
|---|---|
| Grades | SS 321, SS 321H |
| Bolt / Stud Standard | ASTM A193 / ASME SA193 |
| Nut Standard | ASTM A194 / ASME SA194 |
| Dimensional Standards | DIN 931, 933, 934, 7991; ASME B18.2.1, B18.2.2, B18.3; ISO 4032/4033 |
| Threads | Metric (coarse/fine), UNC, UNF, BSW, BSF |
| Form | Bolts, nuts, studs, screws, washers, threaded rod |
| Surface | Passivation / plain; coatings on request |
| Certification | EN 10204 3.1 MTC, PED 97/23/EC available |
We Supplied a Comprehensive Range Of 321 Stainless Steel Fasteners
Related Types Of Stainless Steel 321 Bolts
SS 321 Flange Bolt
SS 321 Square Bolt
SS 321 U Bolt
SS 321 Carriage Bolt
SS 321 Hex Head Bolt
SS 321 Wing Bolt
SS 321 Eye Bolt
SS 321 Hex Bolt
Stainless Steel 321 Fasteners Chemical Composition (% by weight)
| Element | SS 321 (min–max) |
|---|---|
| Carbon (C) | 0.08 max (321H: 0.04–0.10) |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 0.75 max |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.030 max |
| Chromium (Cr) | 17.00 – 19.00 |
| Nickel (Ni) | 9.00 – 12.00 |
| Titanium (Ti) | 5 × (C+N) min – 0.70 max |
| Nitrogen (N) | 0.10 max |
| Iron (Fe) | Balance |
Stainless Steel 321 Fasteners Mechanical Properties (Annealed)
| Property | Value |
|---|---|
| Tensile Strength | 515 MPa (75 ksi) min |
| Yield Strength (0.2% proof) | 205 MPa (30 ksi) min |
| Elongation (in 50 mm) | 40% min |
| Hardness, Rockwell B | 95 HRB max |
| Hardness, Brinell | 217 HB max |
Physical Properties of Stainless Steel 321 Fasteners
| Property | Value |
|---|---|
| Density | 8.0 g/cm³ (8027 kg/m³) |
| Melting Range | approx. 1398 – 1446 °C |
| Elastic Modulus | 193 GPa |
| Thermal Conductivity (100 °C) | 16.1 W/m·K |
| Specific Heat (0–100 °C) | 500 J/kg·K |
Equivalent Grades of Stainless Steel 321 Fasteners
| Standard / Country | Designation |
|---|---|
| UNS (USA) | S32100 |
| Werkstoff / DIN (Germany) | 1.4541 / X6CrNiTi18-10 |
| EN (Euronorm) | X6CrNiTi18-10 |
| JIS (Japan) | SUS 321 |
| BS (UK) | 321S31 |
| AFNOR (France) | Z6CNT18-10 |
| SS (Sweden) | 2337 |
Stainless Steel 321 Fasteners Applications
Because SS 321 fasteners thrive where temperature and corrosion meet, they are specified across the most demanding sectors:
- Oil & Gas / Petrochemical — Refinery piping, flanged joints, and pressure equipment exposed to heat and aggressive media.
- Power & Energy — Boilers, superheaters, steam lines, and nuclear-grade assemblies (especially 321H).
- Aerospace & Defence — Exhaust systems, airframe components, and high-temperature engine hardware.
- Heat Exchangers & Boilers — Tube-sheet bolting and assemblies subject to thermal cycling.
- Chemical Processing — Reactors, pressure vessels, and pipework in oxidizing chemical environments.
- Pharmaceutical & Food — Hygienic equipment requiring corrosion resistance and cleanability.
- Marine & Sea Water — Fastening for equipment exposed to salt-laden atmospheres.
- Pulp & Paper — Process machinery operating in hot, corrosive conditions.
SS 321 vs SS 304 vs SS 347 — Comparison
All three are austenitic stainless steels, but stabilization and temperature behaviour set them apart.
| Criterion | SS 321 | SS 304 | SS 347 |
|---|---|---|---|
| Stabilizer | Titanium | None | Niobium (Nb) |
| Intergranular corrosion resistance | Excellent | Limited | Excellent |
| Max service temperature | ~870 °C | ~870 °C (scaling) | ~870 °C |
| Weldability (thick sections) | Excellent | Good* | Excellent |
| High-temp creep strength | High | Moderate | High |
| Typical cost | Moderate | Lower | Higher |
| Best for | Welded, heat-exposed parts | General purpose | Severe high-temp service |
*304 can sensitize in the 425–815 °C range unless the low-carbon 304L variant is used.
Manufacturing, Testing & Quality Assurance
Manufacturing Capabilities
- Hot forging, cold forging, and CNC machining for precise, repeatable geometry.
- Wire drawing, cold heading, thread rolling, and insert tapping.
- Custom sizes, special threads, and OEM/ODM manufacturing to drawing.
Testing & Inspection
- Tensile and proof-load testing to ASTM A193 / A194.
- Hardness testing (Rockwell / Brinell).
- Chemical analysis (PMI / spectrometry) for grade confirmation.
- Intergranular corrosion (IGC) and ferritescope checks on request.
- Radiography and X-ray testing where specified.
- Dimensional and visual inspection on every batch.
Documentation & Packaging
Every consignment is supplied with EN 10204 3.1 mill test certificates, raw-material traceability, and heat-number marking. Optional third-party inspection (e.g., Lloyd’s, Bureau Veritas, SGS) is available. Fasteners are packed in sealed cartons, wooden boxes, or pallets for safe domestic and export shipment.
Certifications & Standards
- EN 10204 3.1 Mill Test Certificate (standard with every order).
- ASTM A193 / ASME SA193 (bolts & studs), ASTM A194 / ASME SA194 (nuts).
- PED 97/23/EC compliance available for pressure applications.
- ISO-certified quality management system.
- Dual certification as per ASTM & ASME codes on request.
Our Related Products
Frequently Asked Questions
A: Stainless Steel 321 (UNS S32100, Werkstoff 1.4541) is a titanium-stabilized austenitic stainless steel containing about 17–19% chromium and 9–12% nickel. The titanium prevents chromium-carbide precipitation, giving the alloy strong resistance to intergranular corrosion and high-temperature scaling up to roughly 816 °C.
A: SS 321 has up to 0.08% carbon for general use, while SS 321H is the high-carbon variant (0.04–0.10% C) engineered for greater creep strength above 537 °C. Choose 321H for boilers, superheaters, and sustained high-temperature pressure service.
A: Grade 321 fasteners are typically rated for continuous service up to about 816 °C (1500 °F), with good oxidation resistance and intermittent capability higher still, depending on the application.
A: In the annealed condition SS 321 is essentially non-magnetic. Heavy cold working (such as thread rolling) can induce slight magnetism, which is normal for austenitic stainless steels.
A: Bolts and studs are commonly produced to ASTM A193 / ASME SA193 and nuts to ASTM A194 / ASME SA194, with dimensions to DIN, ISO, BS, and ASME B18 series standards.
For More Information About Stainless Steel 321 Fasteners please call +91-22-66362223 / 66394926 or send an email to export@aashishmetal.com
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