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SS 321 Washers Manufacturer & Exporter in India

Explore SS 321 Washers 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 Washers?

SS 321 washers are flat, punched, or machined fastener components manufactured from stabilized austenitic stainless steel grade 321 (UNS S32100), conforming to ASTM A240 or ASTM A276. The addition of titanium (Ti) in SS 321 prevents chromium carbide precipitation during welding and high-temperature service, making these washers ideal for bolted joints exposed to temperatures up to 870°C (1600°F).

SS 321 washers are widely specified for flange assemblies, pipe supports, and structural connections in thermal cycling and oxidizing environments where standard 304/316 washers may fail due to intergranular corrosion or scaling. All washers are supplied with full traceability and EN 10204 3.1 certification.

Quick Specifications

MaterialStainless Steel 321
UNS NumberS32100
DIN Number1.4541
Material StandardASTM A240 / ASTM A276
Washer Standard (Metric)DIN 125 / DIN 9021 / ISO 7089
Washer Standard (Inch)ASME B18.22.1
TypeFlat, Spring, Tab, Serrated
Size RangeM3-M100 / 1/8"-4"
Tensile Strength515 MPa (75 ksi) min
Yield Strength205 MPa (30 ksi) min
HardnessMax 95 HRB
? All washers supplied with PMI and laboratory certification. Custom sizes 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 Studs, 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 Studs
SS 321 Threaded Rods

Technical Data

SS 321 Washers Dimensions, Sizes & Thread Standards

SS 321 Washers are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 125 (flat), DIN 127 (spring), DIN 9021 (large OD), ISO 7089/7090. Custom OD/ID and thicknesses available. Inch sizes per ASME B18.22.1. All SS 321 washers dimensions are verified against applicable DIN, ISO, and ASME B18

Flat Washer Dimensions - Metric (DIN 125 / ISO 7089)

Size (M)Inner Dia (mm)Outer Dia (mm)Thickness (mm)
M33.270.5
M66.4121.6
M88.4161.6
M1010.5202.0
M1213.0242.5
M1617.0303.0
M2021.0373.0
M2425.0444.0
M3031.0564.0
M3637.0665.0
M4243.0786.0
M4849.0926.0
M5657.01058.0
M6465.01158.0
M7273.013010.0
M8081.014010.0
M100101.018012.0

Dimensional & Material Standards

StandardCoversType
DIN 125Flat washersMetric
DIN 127Spring lock washersMetric
DIN 9021Large OD washersMetric
ISO 7089Plain washersMetric
ASME B18.22.1Plain & lock washersInch
BS 4320Form A-G washersMetric
Material StandardRequirement
ASTM A240Plate/sheet - UNS S32100
ASTM A276Bar/rod - UNS S32100
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

SS 321 Chemical Composition

SS 321 Washers 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 A240/A276

ElementComposition (%)
Chromium (Cr)17.0-19.0
Nickel (Ni)9.0-12.0
Titanium (Ti)5xC min, 0.70 max
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
Iron (Fe)Balance
? All heats spectro-tested and certified by NABL-accredited laboratory. PMI available on request.

Why SS 321 Alloy Composition Matters for Washers

Titanium Stabilization — Intergranular Corrosion Resistance
Titanium in SS 321 binds carbon, preventing chromium carbide formation at grain boundaries. This ensures washers retain corrosion resistance after welding or high-temperature exposure, unlike 304/316 washers.
High-Temperature Oxidation Resistance
The 17–19% chromium and 9–12% nickel content provides excellent scaling resistance up to 870°C, making SS 321 washers ideal for bolted joints in exhausts, heat exchangers, and furnace assemblies.
No Sensitization During Fabrication
SS 321 washers can be welded or stress-relieved without risk of intergranular attack, ensuring long-term reliability in cyclic thermal environments.

Fastener Performance

SS 321 Washers Mechanical Properties & Hardness Reference

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

Washer SizeRecommended Hardness (HRB)Max Load (kN)
M6=957.0
M10=9517.0
M16=9540.0
M20=9565.0
M24=9595.0
M30=95150.0
M36=95220.0
M48=95350.0
?? Washer hardness must not exceed bolt/nut hardness. For high-strength bolting, specify through-hardened washers to avoid embedding.

Industry Applications

SS 321 Washers Applications — Industries & End Uses

SS 321 Washers 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 washers are used in heat exchanger flange assemblies, reactor closures, and piping supports in refineries and petrochemical plants. Their resistance to intergranular corrosion and scaling at high temperatures ensures reliable bolted joints in process units and fired heaters.
Flat and spring washers for gas turbine exhausts, HRSG ducting, and boiler manways. SS 321 washers maintain integrity under thermal cycling and prevent bolt loosening in high-temperature flanged joints.
SS 321 washers are specified for aircraft engine mounts, exhaust manifolds, and nacelle assemblies where resistance to oxidation and thermal fatigue is critical. AMS 5510/5645 grades available for aerospace applications.
Used in acid and caustic process piping, pressure vessel nozzles, and agitator assemblies where welded joints and high temperatures demand stabilized stainless washers to prevent intergranular attack.

SS 321 Washers Standards & International Certifications

SS 321 Washers 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 125A DIN 126 DIN 127 DIN 128 DIN 433 DIN 434 DIN 436 DIN 6796 DIN 6797 DIN 9021 ISO 7089 ISO 7090 ISO 7091 ISO 7092 ISO 7093 ISO 7094 ASME B18.21.1 EN ISO 7089 BS 4320 IS 5372 IS 1367 IS 12427
Certifications
ISO 9001:2015PED 2014/68/EUNABL LabMTC 3.1 / 3.2

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

Partner with RealBolt — India’s leading manufacturer of certified SS 321 Washers — 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.
022-6743-7972
+91 90226 36025
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Answers for Buyers

SS 321 Washers — Frequently Asked Questions

Browse expert answers to common questions about SS 321 Washers 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 washers selection and pricing.
SS 321 washers are available to DIN 125 (flat), DIN 127 (spring), DIN 9021 (large OD), ISO 7089/7090, and ASME B18.22.1 (inch). Special forms such as tab, serrated, and conical washers can be supplied to BS 4320 or customer drawings. All washers are manufactured from ASTM A240/A276 certified plate or bar.
Yes – SS 321 washers are stabilized with titanium, providing excellent resistance to scaling and intergranular corrosion up to 870°C (1600°F). They are ideal for bolted joints in exhausts, heat exchangers, and furnace assemblies where standard 304/316 washers may fail.
Absolutely. The titanium stabilization in SS 321 prevents carbide precipitation during welding, ensuring washers retain corrosion resistance and mechanical properties even after exposure to welding heat or post-weld stress relief.
No MOQ for standard sizes (M6-M36) held in stock – we supply from single pieces for urgent maintenance. Custom OD/ID or thicknesses have a 5 kg minimum. Large project quantities receive tiered pricing at 100, 500, and 1000 pcs.

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