Precision-engineered SS washers in grades 304, 316 & 316L - ready stock, custom sizes up to 4", and certified for marine, petrochemical & structural applications.
Size Range: M2 - M100 | Grades: SS 304 / 316 / 316L / 202 | OD Range: 3 - 300 mm | Certification: EN 10204 3.1 MTC
Unifit Fastener manufactures stainless steel washers in grades SS 304, 316, 316L and 202, blanked and pierced to DIN 125, ISO 7089 and ASME B18.22.1 from certified mill coil. We supply flat, spring, square, lock, fender, Belleville and taper washers from M2 to M100, with custom bores, ODs and thicknesses produced for drawing. Every lot is passivated to ASTM A967, checked for dimensional conformance and heat number, and shipped with an EN 10204 3.1 Mill Test Certificate; EN 10204 3.2 third-party inspection (SGS, TUV, Bureau Veritas) is available on request. Standard sizes ship from ready stock in 7–15 days to India and 30+ export markets. From ready-stock standard sizes to made-to-drawing specials, Unifit Fastener helps engineers, EPC contractors and stockists across India and 30+ export markets fasten with confidence. Explore our washer range below, or request a quote for your exact specification.
Request a Quote| Attribute | Specification |
|---|---|
| Material Grades | Align to the controlled grade list agreed in Fold 3. Remove 410 unless it is genuinely stocked. |
| Standards | ASTM A240 (material) - ASTM F436 (hardened washers) - ASME B18.22.1 (plain) - ASME B18.21.1 (lock) - DIN 125 / 127 / 9021 - ISO 7089 / 7090 - BS 4320 - JIS B 1256 - IS 2016 |
| Size Range | Size Range: M2 - M100 (custom bores and profiles to drawing) |
| Thickness | 0.5 mm to 6 mm (heavier on request) |
| Length / OD Range | 3 mm to 200 mm |
| Thread Standards | Bolt Size Compatibility: M2-M100 metric coarse & fine; #4 - 1-1/2" UNC/UNF imperial bolt series |
| Finish | Mirror, polished, electroplated, PTFE-coated, galvanized |
| Test Certificate | EN 10204 3.1 / 3.1B with PMI & proof load report |
| Packaging | Wooden cases, carton boxes, wooden pallets |
| Attribute | Specification |
|---|---|
| Material Grades | SS 304, 304L, 316, 316L, 317L, 321, 310, 310S, 904L, Duplex, Super Duplex |
| Standards | ASTM A240 (material) - ASTM F436 (hardened washers) - ASME B18.22.1 (plain washers) - ASME B18.21.1 (lock washers) - DIN 125 / DIN 127 / DIN 9021 - ISO 7089 / ISO 7090 - BS 4320 - JIS B 1256 - IS 2016 |
| Size Range | M2 - M100 (custom bores and profiles as per drawing) |
| Thickness | 0.5 mm to 6 mm (heavier thickness available on request) |
| Outside Diameter (OD) | 3 mm to 200 mm |
| Bolt Size Compatibility | M2-M100 Metric (Coarse & Fine) - #4 - 1-1/2" UNC/UNF Imperial Bolt Series |
| Finish | Mirror, Polished, Electroplated, PTFE Coated, Hot-Dip Galvanized |
| Test Certificate | EN 10204 3.1 / 3.1B with PMI Report & Proof Load Report |
| Packaging | Wooden Cases, Carton Boxes, Wooden Pallets or as per customer requirements |
| MOQ | 5 Pieces (Trial Orders Accepted) - Bulk and FCL Pricing Available on Request |
| HSN Code & Tax | HSN Code: 7318.22.00 - GST: 18% (India) - RoDTEP Eligible for Export Orders |
| Washer Size | Approximate Weight (kg per 1,000 pcs) |
|---|---|
| M2 | 0.05 |
| M2.5 | 0.08 |
| M3 | 0.13 |
| M4 | 0.24 |
| M5 | 0.44 |
| M6 | 1.02 |
| M8 | 1.83 |
| M10 | 3.57 |
| M12 | 6.27 |
| M14 | 8.55 |
| M16 | 11.30 |
| M18 | 14.10 |
| M20 | 17.20 |
| M22 | 24.10 |
| M24 | 32.30 |
| M27 | 46.50 |
| M30 | 59.80 |
| M33 | 79.20 |
| M36 | 103.50 |
| Grade | Best For | Key Advantage |
|---|---|---|
| SS 304 | General industrial, indoor, mild acids | Cost-effective, non-magnetic, versatile |
| SS 316 | Marine, coastal, chemical exposure | Superior chloride & pitting resistance |
| SS 316L | Welded marine & petrochemical joints | Low carbon, excellent weldability |
| SS 321 | High-temperature / aerospace | Titanium-stabilised heat resistance |
| SS 202 | Budget indoor, decorative | Economical, good formability |
| Property | SS 304 | SS 316 |
|---|---|---|
| Corrosion resistance | Good (general) | Excellent (marine/chloride) |
| Molybdenum content | None | 2-3% (added pitting resistance) |
| Typical use | Indoor, structural, food-grade | Offshore, chemical, coastal |
| Relative cost | Lower | Higher |
| Nominal Size | Inner Diameter (ID) mm | Outer Diameter (OD) mm | Thickness (mm) |
|---|---|---|---|
| M3 | 3.2 | 7 | 0.5 |
| M4 | 4.3 | 9 | 0.8 |
| M5 | 5.3 | 10 | 1.0 |
| M6 | 6.4 | 12 | 1.6 |
| M8 | 8.4 | 16 | 1.6 |
| M10 | 10.5 | 20 | 2.0 |
| M12 | 13.0 | 24 | 2.5 |
| M14 | 15.0 | 28 | 2.5 |
| M16 | 17.0 | 30 | 3.0 |
| M20 | 21.0 | 37 | 3.0 |
| M24 | 25.0 | 44 | 4.0 |
| M30 | 31.0 | 56 | 4.0 |
| M36 | 37.0 | 66 | 5.0 |
| Washer Size | Thickness (Min-Max) (in) | Outside Diameter (Min-Max) (in) | Inside Diameter (Min-Max) (in) |
|---|---|---|---|
| #4 | 0.025 - 0.040 | 0.307 - 0.320 | 0.120 - 0.133 |
| #6 | 0.036 - 0.065 | 0.370 - 0.390 | 0.151 - 0.164 |
| #8 | 0.036 - 0.065 | 0.433 - 0.453 | 0.183 - 0.196 |
| #10 | 0.036 - 0.065 | 0.495 - 0.515 | 0.214 - 0.227 |
| 3/16" | 0.036 - 0.065 | 0.557 - 0.577 | 0.245 - 0.265 |
| #12 | 0.051 - 0.080 | 0.557 - 0.577 | 0.245 - 0.265 |
| 1/4" | 0.051 - 0.080 | 0.620 - 0.640 | 0.276 - 0.296 |
| 5/16" | 0.051 - 0.080 | 0.681 - 0.703 | 0.339 - 0.359 |
| 3/8" | 0.051 - 0.080 | 0.805 - 0.827 | 0.401 - 0.419 |
| 7/16" | 0.051 - 0.080 | 0.915 - 0.937 | 0.464 - 0.484 |
| 1/2" | 0.074 - 0.121 | 1.055 - 1.092 | 0.526 - 0.546 |
| 9/16" | 0.074 - 0.121 | 1.149 - 1.186 | 0.589 - 0.609 |
| 5/8" | 0.074 - 0.121 | 1.305 - 1.342 | 0.649 - 0.686 |
| 3/4" | 0.108 - 0.160 | 1.462 - 1.499 | 0.805 - 0.842 |
| 7/8" | 0.108 - 0.160 | 1.743 - 1.780 | 0.931 - 0.968 |
| 1" | 0.108 - 0.160 | 1.993 - 2.030 | 1.055 - 1.092 |
| 1-1/8" | 0.108 - 0.160 | 2.243 - 2.280 | 1.243 - 1.280 |
| 1-1/4" | 0.136 - 0.192 | 2.493 - 2.530 | 1.368 - 1.405 |
| 1-3/8" | 0.136 - 0.192 | 2.743 - 2.780 | 1.493 - 1.530 |
| 1-1/2" | 0.153 - 0.192 | 2.993 - 3.030 | 1.618 - 1.655 |
| DIN Standards | BS Standards | ISO Standards | JIS Standards |
|---|---|---|---|
| DIN 125 - Flat Washers | BS 4320 - Plain Washers | ISO 7089 - Plain Flat Washers | JIS B 1256 - Plain Washers |
| DIN 9021 - Large OD Washers | BS 4320 Form G - Large Series Washers | ISO 7090 - Chamfered Flat Washers | JIS B 1251 - Spring Washers |
| DIN 6798 - Serrated Lock Washers | BS 4464 - Spring Washers | ISO 7092 - Small Series Washers | JIS B 1255 - Tooth Lock Washers |
| DIN 7349 - Thick plain washers for bolts with heavy clamping | BS 4463 - Crinkle Washers | ISO 8738 - Plain washers for clevis pins | JIS B 1252 - Taper Washers |
Our stainless steel washers perform in demanding load-bearing and corrosive environments across sectors:
| Industry | Where Our Washers Are Used |
|---|---|
| Oil, Gas & Petrochemical | Flanged joints, refinery piping, offshore platforms |
| Marine & Shipbuilding | Deck fittings, corrosion-critical hull assemblies |
| Power & Renewable Energy | Wind towers, solar structures, turbine mounts |
| Construction & Infrastructure | Structural steel, bridges, heavy timber joints |
| Automotive & Railways | Vibration-prone assemblies, chassis fastening |
| Aerospace & Defence | High-temperature, high-integrity connections |
| Food, Pharma & Water | Hygienic, corrosion-resistant equipment |
Unifit Fastener offers factory-direct prices for stainless steel washers, available on a per kilogram or per 1,000 pieces basis with no trader mark-up. The final price depends on the material grade, washer dimensions, surface finish, order quantity, and certification requirements.
The key factors affecting stainless steel washer prices include:
Unifit Fastener returns competitive factory prices within 24 hours for standard and custom stainless steel washers. Simply share your Bill of Quantity (BOQ), technical drawing, or specification, and our team will provide a detailed quotation along with the required EN 10204 3.1 Material Test Certificate (MTC).
| Standard Body | Washer Standards Covered |
|---|---|
| DIN (German) | DIN 125, DIN 127, DIN 436, DIN 6796, DIN 9021, DIN 6798 |
| ISO (International) | ISO 7089, ISO 7090, ISO 7092, ISO 7093 |
| ASME / ASTM (American) | ASME B18.21.1, ASTM A240/A240M, SAE flat washers |
| BS (British) | BS 4320 plain, BS 4464 spring, BS 4463 crinkle |
| JIS (Japanese) | JIS B 1256 plain, JIS B 1251 spring |
| IS (Indian) | IS 2016 plain, IS 3063 spring |
Available coatings & finishes: PTFE coated, hot-dip galvanized, zinc plated (yellow/blue/black), zinc-cobalt, nickel plated, black phosphate and mirror-polished.
SS 316L has a maximum carbon content of 0.035% compared to 0.08% in standard SS 316. The lower carbon reduces the risk of carbide precipitation during welding, making 316L the preferred choice for welded assemblies exposed to corrosive environments.
We manufacture nuts from M3 to M100 (approximately 3/16" to 4"), with custom sizes available on request to match project drawings.
Yes. The added molybdenum content gives SS 316/316L superior resistance to chloride pitting and crevice corrosion, making these grades a standard choice for marine, offshore, and coastal construction projects.
Yes, every shipment includes an EN 10204 3.1 Mill Test Certificate as standard, with 3.2 third-party certification available on request.
We offer PTFE, Xylan, zinc, phosphate, cadmium, and hot-dip galvanized coatings, along with passivation and electro-polishing finishes.
