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SS 321 Studs Manufacturer & Exporter in India

Explore SS 321 Studs Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-196

Min Temp

870

Max Temp

🌡

870

Suitable for continuous service up to approximately 870°C under typical operating conditions.

⚡

620

Typical tensile strength around 620 MPa depending on product form and heat treatment.

🛡

Very Good

Very Good corrosion resistance in a wide range of industrial environments.

⚖

8

Typical density is approximately 8.0 g/cm³.

Product Overview

What are SS 321 Studs?

SS 321 studs are threaded fasteners manufactured from stabilized austenitic stainless steel, specifically UNS S32100, conforming to ASTM A193 and ASTM A276 standards. Alloy 321 is titanium-stabilized, providing superior resistance to intergranular corrosion and improved performance at elevated temperatures compared to standard 304/316 grades.

SS 321 studs are widely specified for high-temperature flange connections, heat exchanger assemblies, and process piping in refineries, chemical plants, and power generation facilities. Their ability to resist carbide precipitation during welding and service makes them ideal for applications requiring repeated thermal cycling or exposure to temperatures up to 870°C.

Quick Specifications

MaterialStainless Steel 321
UNS NumberS32100
DIN Number1.4541
Material StandardASTM A276 / ASTM A193
Stud Standard (Metric)DIN 976 / DIN 975
Stud Standard (Inch)ASME B16.5 / B18.31.2
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength515 MPa (75 ksi) min
Yield Strength205 MPa (30 ksi) min
HardnessMax 223 HB
? All material certified by NABL-accredited laboratory. PMI and IGC test available on request.

Complete the Fastener Set

Other SS 321 Fastener Products Available from RealBolt

RealBolt also manufactures the complete SS 321 fastener range from certified stainless steel bar stock, including SS 321 Bolts, SS 321 Nuts, SS 321 Screws, SS 321 Washers, and SS 321 Threaded Rods. All SS 321 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
SS 321 Bolts
SS 321 Nuts
SS 321 Screws
SS 321 Washers
SS 321 Threaded Rods

Technical Data

SS 321 Studs Dimensions, Sizes & Thread Standards

SS 321 Studs are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 976 (full thread) / DIN 975 (threaded rod) / ASME B16.5 (stud bolts for flanges). Custom cut lengths available in 5mm increments. Inch dimensions per ASME B18.31.2.

Stud Dimensions - Metric (DIN 976)

Size (M)Pitch (mm)Thread Length (mm)Min L (mm)Max L (mm)
M61.0Full202000
M81.25Full202000
M101.5Full202000
M121.75Full202000
M162.0Full302000
M202.5Full402000
M243.0Full502000
M303.5Full602000
M364.0Full802000
M424.5Full1002000
M485.0Full1202000
M565.5Full1402000
M646.0Full1602000
M726.0Full1802000
M806.0Full2002000
M1006.0Full2502000

Dimensional & Material Standards

StandardCoversThread
DIN 976Full thread studsMetric
DIN 975Threaded rodsMetric
ASME B16.5Stud bolts for flangesUNC
ASME B18.31.2Continuous thread studsUNC/UNF
ISO 898-1Mechanical propertiesMetric
Material StandardRequirement
ASTM A276Bar/rod - UNS S32100
ASTM A193 B8TStuds for high temp/pressure
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

SS 321 Chemical Composition

SS 321 Studs are manufactured from an iron-chromium-nickel alloy with chromium (16–26%), nickel (8–28%), and grade-specific molybdenum additions per ASTM and ASTM A193/A194. Chromium content governs the self-healing passive oxide film; molybdenum (2–6%) enhances chloride pitting resistance; and carbon content determines sensitization risk in welded assemblies.

Chemical Composition per ASTM A276 / A193

ElementComposition (%)
Chromium (Cr)17.0-19.0
Nickel (Ni)9.0-12.0
Carbon (C)0.08 max
Manganese (Mn)2.00 max
Silicon (Si)0.75 max
Phosphorus (P)0.045 max
Sulfur (S)0.030 max
Titanium (Ti)5xC min, 0.70 max
Iron (Fe)Balance
? All heats verified by NABL-accredited spectrometry. PMI and IGC test available on request.

Why SS 321 Alloy Composition Matters for Studs

Titanium Stabilization
Titanium in SS 321 binds carbon, preventing chromium carbide precipitation at grain boundaries. This ensures resistance to intergranular corrosion during welding and high-temperature service, making SS 321 studs ideal for repeated thermal cycling.
High-Temperature Strength
The alloy’s chromium and nickel content provides excellent oxidation resistance and mechanical strength up to 870°C, outperforming standard 304/316 studs in heat exchanger and furnace applications.
Weldability
SS 321 studs can be welded without risk of sensitization, maintaining corrosion resistance in the heat-affected zone — critical for pressure vessel and piping assemblies.

Fastener Performance

SS 321 Studs Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for SS 321 Studs per ASTM. SS 321 studs achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Stud SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12705625
M1617013650
M2034027280
M24590472120
M301200960190
M3621001680275
M4233002640370
M4848003840500
?? Anti-galling: Use molybdenum-based or PTFE anti-seize. Lubricated values assume K=0.16. Avoid copper-based anti-seize in chloride environments.

Industry Applications

SS 321 Studs Applications — Industries & End Uses

SS 321 Studs from RealBolt are specified across food and dairy, pharmaceutical, marine, chemical processing, and oil and gas where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
SS 321 studs are the preferred choice for ASME B16.5/B16.47 flange connections in refinery heaters, catalytic reformers, and process piping where resistance to polythionic acid stress corrosion and high-temperature oxidation is critical.
Studs for heat recovery steam generator (HRSG) ducting, boiler manways, and superheater header connections, where thermal cycling and high-temperature steam require stabilized stainless steel fasteners.
Used in chemical reactor closures, pressure vessel nozzles, and heat exchanger channel covers exposed to organic acids, urea, and nitric acid environments where 304/316 studs may fail due to sensitization.
SS 321 studs are specified for jet engine exhaust assemblies, thermal processing furnaces, and high-temperature ductwork where oxidation resistance and mechanical stability at elevated temperatures are essential.

SS 321 Studs Standards & International Certifications

SS 321 Studs from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, IS 12427 compliance, ISO 3506 material certification, NACE MR0175, and PMI (XRF) reports — available on request for all orders.
Standards
DIN 938 DIN 939 DIN 976-1 ASME B18.31.2 IS 1364 IS 1367 IS 12427
Certifications
ISO 9001:2015PED 2014/68/EUNABL LabEN 10204 3.1 / 3.2

Buy SS 321 Studs from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified SS 321 Studs — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
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Answers for Buyers

SS 321 Studs — Frequently Asked Questions

Browse expert answers to common questions about SS 321 Studs from RealBolt — covering ASTM A193/A194 grades, chloride resistance, temperature limits, sensitization, sizes, and MTC documentation. Contact our technical team directly for project-specific guidance on SS 321 studs selection and pricing.
SS 321 studs and threaded rods are available to DIN 976 (full thread), DIN 975 (threaded rod), ASME B16.5 (stud bolts for flanges), and ASME B18.31.2 (continuous thread studs). Custom thread forms (UNC, UNF, BSW, BSF) and cut lengths are available on request with short lead times.
For SS 321 studs, use a molybdenum-based or PTFE anti-seize compound to prevent galling and seizing during assembly. Avoid copper-based anti-seize in chloride-rich or high-temperature environments to prevent galvanic corrosion. Lubricated torque values should be reduced by 20% compared to dry assembly.
Yes – SS 321 studs are specifically designed for high-temperature service up to 870°C, making them ideal for flange connections in heaters, boilers, and exhaust systems. Their titanium stabilization prevents intergranular corrosion during thermal cycling and welding.
There is no formal MOQ for standard sizes (M12-M36) available ex-stock – single pieces can be supplied for urgent maintenance. Custom sizes or cut-to-length studs may require a minimum order of 10 kg. Quantity discounts are available at 50, 200, and 500 pieces.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
  • Canada
  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil