Email:
[email protected]
Phone:
+91 93135 43530
Address:
133/1 Ground, Mansuri Block, Opp. Dudheshwar Water Tank, Ahmedabad-380004, Gujarat, India
Stainless Steel Washers Supplier India — Krishna Industries (KELOR), Ahmedabad
B2B supplier of SS Washers in all types and grades — SS304 (A2) / SS316 (A4) / SS316L — Plain Flat / Spring Lock / Nord-Lock / Conical / Fender / Toothed Lock / Square — M3 to M56 — DIN 125 / DIN 127 / ASME B18.21.1 / ISO 7089 / IS 1831 standards.
MTC on Request · MOQ 100 Nos · GST Invoice (GSTIN: 24AKLPP6499B1ZT) · Pan India Dispatch from Ahmedabad · 2-Hour Quote
A stainless steel washer (SS washer) is a thin flat disc with a central hole — placed under a bolt head or nut to distribute clamping load over a larger surface area, prevent surface damage, fill gaps, and reduce the risk of loosening under vibration. Stainless steel grades — primarily SS304 (A2) and SS316 (A4) — provide corrosion resistance that carbon steel or zinc-plated washers cannot match in wet, marine, chemical, outdoor, and food-grade environments.
Krishna Industries (KELOR), based in Ahmedabad, Gujarat, supplies the complete range of stainless steel washers — all types, all grades, all standards — to industrial buyers, EPC contractors, valve and pump OEMs, and MRO stores across India. GST invoice. MOQ 100 Nos. Pan India dispatch.
SS Grade Selection Guide — SS304 vs SS316 vs SS316L
The most common ordering mistake: specifying SS304 washers for outdoor marine or chemical installations where SS316 is required. Use this table before ordering.
| Grade | Designation | Key Property | ✅ Specify For | ❌ Not For |
|---|---|---|---|---|
| SS304 (A2) | AISI 304 / UNS S30400 / DIN 1.4301 | 18% Cr + 8% Ni — general corrosion resistance | ✅ Indoor industrial, HVAC, food processing non-chloride, pharmaceutical non-GMP, general engineering, water supply (non-coastal) — most economical SS grade | Chloride-rich service, seawater, outdoor coastal — SS304 pits in chloride above ~150 ppm |
| SS316 (A4) | AISI 316 / UNS S31600 / DIN 1.4401 | 18% Cr + 10% Ni + 2–3% Mo — chloride pitting resistance | ✅ Marine, coastal, offshore, chemical, seawater, chloride service, food GMP, pharmaceutical process, outdoor coastal industrial — standard for all outdoor and marine SS washer specifications | Very high temp above 425°C continuous (use higher alloy) |
| SS316L (A4L) | AISI 316L / UNS S31603 / DIN 1.4404 | Low carbon (0.03% max C) — weld sensitisation resistance | ✅ Welded assemblies in corrosive service — where intergranular corrosion from carbide precipitation at weld heat-affected zone must be avoided — pharma, chemical, food GMP | Standard non-welded service where SS316 is adequate and lower cost |
| SS410 (Martensitic) | AISI 410 / UNS S41000 | 13% Cr — hardenable — moderate corrosion resistance | Cutlery, pump shafts, valve trim — heat-treatable — where hardness needed alongside moderate corrosion resistance | Marine, chemical, food — SS410 has lower corrosion resistance than SS304 |
SS Washer Types — Complete Range
MOST COMMON
Plain Flat Washer (DIN 125 / ISO 7089)
- Flat disc — distributes bolt load over larger area
- Prevents surface damage under bolt head / nut
- DIN 125 (standard OD) / DIN 9021 (large OD fender)
- Sizes: M3 to M56
- ✅ Standard for all general bolted joints — most specified SS washer type
ANTI-VIBRATION
Spring Lock Washer (DIN 127)
- Split ring — one end raised above the other
- Spring action maintains bolt preload under vibration
- Bites into bolt face and mating surface on loosening
- DIN 127B standard — metric M3 to M30
- ✅ Pumps, motors, compressors, vibrating machinery
- ⚠️ Not for structural joints — use Nord-Lock there
HIGH VIBRATION
Nord-Lock / Wedge Lock Washer
- Two-piece washer — cam faces on back, serrations on outer faces
- Wedge action prevents back-rotation under vibration
- Significantly more reliable than spring washer for high vibration
- Used in rail, heavy machinery, structural joints subject to dynamic load
- ✅ Where spring washer insufficient — heavy vibration service
SEALING
Conical (Belleville) Washer (DIN 6796)
- Cone-shaped disc — acts as spring under compression
- Maintains bolt preload when gasket relaxes
- DIN 6796 — metric M4 to M48
- ✅ Flanged joints, pressure vessel bolting, gasketed joints where relaxation is expected
ANTI-LOOSENING
Toothed Lock Washer (DIN 6797)
- Internal teeth (J-type) or external teeth (A-type)
- Teeth bite into bolt and mating surface — prevents rotation
- DIN 6797J (internal) / DIN 6797A (external)
- ✅ Electrical connections, panel mounting, lighter duty anti-loosening
LARGE BEARING AREA
Fender / Penny Washer (DIN 9021)
- Large OD — extra-wide bearing surface
- Distributes load over large soft material area
- DIN 9021 — OD approximately 3× bolt diameter
- ✅ Thin sheet metal, wood, GRP, soft substrate — where standard washer OD insufficient
SQUARE / STRUCTURAL
Square Washer (DIN 436)
- Square plate instead of circular disc
- Used with square neck bolts / carriage bolts
- DIN 436 — sizes M6 to M30
- ✅ Timber, structural, rail — where round washer can rotate in slot
COUNTERSUNK
Countersunk / Finishing Washer (DIN 965)
- Bevelled centre hole — seats countersunk screw head
- Provides flush or recessed finish
- ✅ Countersunk bolt assemblies, furniture, panel work
DIN 125 Plain Flat Washer — SS304 / SS316 Dimensions Table
The most searched reference for SS flat washers in India. All dimensions in mm per DIN 125 (equivalent to ISO 7089).
| Bolt Size | Inner Dia d1 (mm) | Outer Dia d2 (mm) | Thickness h (mm) | Weight approx (g / pc) |
|---|---|---|---|---|
| M3 | 3.2 | 7 | 0.5 | 0.07 |
| M4 | 4.3 | 9 | 0.8 | 0.17 |
| M5 | 5.3 | 10 | 1.0 | 0.26 |
| M6 | 6.4 | 12 | 1.6 | 0.58 |
| M8 | 8.4 | 16 | 1.6 | 0.96 |
| M10 | 10.5 | 20 | 2.0 | 1.72 |
| M12 | 13.0 | 24 | 2.5 | 3.20 |
| M16 | 17.0 | 30 | 3.0 | 5.90 |
| M20 | 21.0 | 37 | 3.0 | 8.80 |
| M24 | 25.0 | 44 | 4.0 | 16.4 |
| M30 | 31.0 | 56 | 4.0 | 26.2 |
| M36 | 37.0 | 66 | 5.0 | 45.8 |
| M42 | 43.0 | 78 | 7.0 | 91.0 |
| M48 | 50.0 | 92 | 8.0 | 152 |
| M56 | 58.0 | 105 | 9.0 | 224 |
DIN 127B Spring Lock Washer — SS304 / SS316 Dimensions Table
Standard split ring spring lock washer dimensions per DIN 127B — all in mm.
| Bolt Size | Inner Dia d (mm) | Outer Dia D (mm) | Width b (mm) | Thickness s (mm) | Height h (mm) |
|---|---|---|---|---|---|
| M3 | 3.1 | 5.8 | 1.0 | 0.8 | 1.6 |
| M4 | 4.1 | 7.6 | 1.2 | 0.9 | 1.8 |
| M5 | 5.1 | 9.2 | 1.4 | 1.2 | 2.4 |
| M6 | 6.1 | 11.8 | 1.6 | 1.6 | 3.2 |
| M8 | 8.2 | 15.0 | 2.0 | 2.0 | 4.0 |
| M10 | 10.2 | 18.1 | 2.2 | 2.5 | 5.0 |
| M12 | 12.2 | 21.1 | 2.5 | 3.0 | 6.0 |
| M16 | 16.2 | 27.4 | 3.0 | 4.0 | 8.0 |
| M20 | 20.2 | 33.6 | 3.8 | 5.0 | 10.0 |
| M24 | 24.5 | 40.4 | 4.5 | 6.0 | 12.0 |
| M30 | 30.5 | 49.8 | 5.0 | 7.0 | 14.0 |
Washer Standards Reference — DIN / ISO / ASME / IS / BS
| Standard | Type | Description |
|---|---|---|
| DIN 125 | Plain flat washer | Standard OD flat washer — most common metric flat washer standard in India — equivalent to ISO 7089 |
| DIN 9021 | Fender / large OD washer | Large OD flat washer — OD approximately 3× bolt diameter — for soft substrate load distribution |
| DIN 127B | Spring lock washer | Split ring spring washer — standard metric spring washer — anti-vibration bolt assemblies |
| DIN 6796 | Conical (Belleville) washer | Disc spring washer — maintains bolt preload in gasketed joints |
| DIN 6797A/J | Toothed lock washer | External (A) or internal (J) serrated washer — anti-rotation electrical and panel connections |
| DIN 436 | Square washer | Square plate washer for timber and structural carriage bolt connections |
| ISO 7089 / 7090 | Plain flat washer | International equivalent of DIN 125 — product grades A (precision) and C (commercial) |
| ASME B18.21.1 | Lock washers | American standard for helical spring lock and toothed washers — inch UNC sizes |
| ASME B18.22.1 | Plain washers | American standard for plain flat washers — SAE and USS series — inch sizes |
| IS 1831 / IS 2016 | Plain washer | Indian Standard for plain washers for metric bolts — used on IS flange bolting specifications |
| BS 4320 | Metal washers | British standard — plain and spring washers for metric bolts |
Which SS Washer to Specify — Selection Guide
⚠️ Most common mistake: Using spring lock washers for structural bolted joints. Research and testing (NASA, German DIN committee) have shown that standard split ring spring lock washers (DIN 127) provide minimal resistance to loosening in high-vibration structural service. For critical high-vibration joints, use Nord-Lock (wedge lock) washers or mechanical locking (prevailing torque nuts, thread locking compound). Spring washers remain appropriate for light to moderate vibration in instrumentation, panel work, and general assembly.
| Application | Recommended Washer | Reason |
|---|---|---|
| Standard bolted joint — general assembly | ✅ DIN 125 Plain Flat Washer (SS304 or SS316) | Load distribution — prevents surface damage — standard specification |
| Pumps, motors, compressors — moderate vibration | ✅ DIN 127B Spring Lock Washer | Spring action maintains preload — biting action resists loosening under moderate cyclic vibration |
| Rail, heavy machinery, structural — high vibration | ✅ Nord-Lock / Wedge Lock Washer | Cam wedge action prevents back-rotation — superior to spring washer in severe vibration |
| Gasketed flanged joints — pressure vessel | ✅ DIN 6796 Conical (Belleville) Washer | Maintains bolt preload as gasket relaxes — prevents joint leakage from bolt load loss |
| Thin sheet metal, wood, GRP, fibre glass | ✅ DIN 9021 Fender / Large OD Washer | Large OD distributes load — prevents pull-through in soft substrate |
| Electrical connections, panel mounting | ✅ DIN 6797A/J Toothed Lock Washer | Teeth bite into surface — prevent rotation — ensure electrical contact |
| Countersunk bolt assemblies | ✅ DIN 965 Countersunk Washer | Bevelled seat for countersunk screw head — flush finish |
| Food, pharma, coastal — corrosion critical | ✅ SS316 (A4) or SS316L grade | Mo addition prevents chloride pitting — no contamination risk vs SS304 in corrosive service |
Industries & Applications — Stainless Steel Washers
🏭 Process & Chemical Plants
Flange bolting washers under A193 B7 stud bolt nuts — SS304 for indoor dry service, SS316 for chloride/outdoor at Ankleshwar, Vapi, Dahej plants.
⚓ Marine & Offshore
SS316 A4 washers for marine equipment, offshore platforms, port structures, shipbuilding — salt water and humid salt air service.
💊 Pharma & Food GMP
SS316L washers for pharmaceutical process equipment, food processing, dairy — no contamination, GMP-compliant, cleanable surface.
⚡ Power Plants & Transformers
SS304 washers for switchgear, transformers, control panels, bus-bar connections — corrosion resistant, non-magnetic austenitic grade.
🏗️ Construction & Infrastructure
SS316 structural washers for bridges, coastal structures, stadiums, facades exposed to weather — long-term corrosion-free service.
🔧 Pumps, Valves & Actuators
SS304 / SS316 washers for pump casing bolting, valve bonnet bolting, actuator mounting — paired with SS stud bolts and hex nuts.
🌊 Water Treatment
SS316 plain flat washers for outdoor water treatment plant flanged connections — paired with HDG B7 stud bolts for outdoor WTP.
🔩 MRO & Plant Maintenance
SS304 and SS316 assortment kits M6–M24 for maintenance store stock — paired with SS hex nuts and hex bolts for shutdown replacement.
Why Industrial Buyers Choose Krishna Industries
🏭
B2B Supplier Since 2017
Sourced from verified Indian fastener manufacturers. Consistent quality across SS304, SS316, SS316L grades. Competitive Ahmedabad pricing.
📄
GST Invoice & MTC
100% GST invoice (GSTIN: 24AKLPP6499B1ZT). MTC — material test certificate for SS grade with composition and mechanical properties — available on request.
🔩
Complete Fastener Range
Stainless steel washers supplied together with SS hex nuts, hex bolts, and A193 B8M stud bolts — complete fastener sets in one order.
📦
MOQ 100 Nos
Minimum 100 Nos per size per type per grade. Mixed size assortment kits for MRO store stock — 50 Nos per size across M6 to M24 — single invoice.
🚚
Pan India Dispatch
Maharashtra, Tamil Nadu, Rajasthan, Karnataka, UP, Delhi NCR and all states via VRL / Professional Courier — 2–7 days transit from Ahmedabad.
⏱️
2-Hour Quote
WhatsApp type (plain / spring / Nord-Lock), grade (SS304 / SS316), size (M__ ), and quantity. Pricing within 2 hours. Mon–Sat 9 AM–7 PM IST.
Need SS Washer Pricing for Your Project or MRO Stock?
WhatsApp washer type (plain / spring / Nord-Lock / conical / fender) · grade (SS304 / SS316 / SS316L) · size (M__) · standard (DIN 125 / DIN 127 / other) · quantity. Quote within 2 hours.
📲 WhatsApp for SS Washer PriceRelated Products — Krishna Industries (KELOR)
- Stud Bolt A193 B7 with 2H Nut — SS washers are commonly ordered alongside stud bolt sets for flanged joint assemblies
- A194 2H Heavy Hex Nut — carbon steel heavy hex nut for A193 B7 stud bolt sets
- A193 B8M Stud Bolt with 8M Nut (SS316) — SS316 stud bolt set for SS flanged connections — order with SS316 washers
Frequently Asked Questions — Stainless Steel Washers
What is the difference between SS304 and SS316 washers?
SS304 (Grade A2) contains 18% chromium and 8% nickel — excellent general corrosion resistance for indoor and non-chloride outdoor service. SS316 (Grade A4) has the same chromium-nickel base plus 2–3% molybdenum — the molybdenum provides resistance to chloride pitting corrosion that SS304 does not have. Specify SS304 washers for indoor industrial, HVAC, food processing non-chloride, and general engineering service. Specify SS316 washers for marine, offshore, coastal industrial, chemical plants with chloride media, outdoor coastal service, food GMP, and pharmaceutical process assemblies. If your bolted joint will be exposed to seawater, salt spray, swimming pool chemicals, or any chloride-containing environment, SS316 is mandatory — SS304 pits and stains in chloride service.
When should I use a spring lock washer instead of a plain flat washer?
Specify spring lock washers (DIN 127B) for bolted assemblies subject to moderate vibration where preventing bolt loosening is a concern — pumps, motors, compressors, rotating machinery, light structural panels. A spring lock washer provides a degree of anti-vibration protection by maintaining spring preload on the nut and biting into both the nut face and mating surface. However, for high-vibration structural joints (rail, heavy machinery, bridges, wind turbines) spring lock washers have limited effectiveness — the DIN 127B split ring can flatten under high preload, losing its spring function. For critical high-vibration structural service, use Nord-Lock wedge lock washers, prevailing torque nuts, or thread locking compound instead. For gasketed flanged joints, use Belleville conical washers which maintain preload as the gasket relaxes.
What are DIN 125 and DIN 127 standards for washers?
DIN 125 is the German standard (equivalent to ISO 7089) that defines dimensions for plain flat washers for metric bolts — inner diameter, outer diameter, and thickness for each bolt size from M3 to M56. DIN 125 is the most widely specified plain washer standard in India and is the default reference when a drawing or specification says “flat washer” without further qualification. DIN 127B is the standard for split ring spring lock washers — the helical split ring washer used as an anti-vibration device. DIN 127B specifies inner diameter, outer diameter, width, and thickness for each metric bolt size. Both standards are available in SS304 (A2) and SS316 (A4) grades from Krishna Industries.
What is the difference between A2 and A4 stainless steel washers?
A2 and A4 are the ISO property class designations for austenitic stainless steel fasteners and washers. A2 corresponds to AISI 304 (SS304) — 18-8 stainless steel with no molybdenum. A4 corresponds to AISI 316 (SS316) — 18-10-3 stainless steel with 2–3% molybdenum. When a specification or purchase order says “A2 washer” it means SS304. When it says “A4 washer” it means SS316. The practical difference is corrosion resistance in chloride environments — A4/SS316 is significantly more resistant to pitting and crevice corrosion in chloride service. A2-70 and A4-80 are the strength class designations — 70 and 80 refer to the minimum tensile strength in units of 10 MPa for the corresponding bolt grade, though for washers (which are not tensile-loaded components) the grade primarily indicates the material.
What is the MOQ and can I order mixed sizes?
MOQ is 100 Nos per size per type per grade. For maintenance store assortment kits — mixed sizes M6 to M24, same type and grade — minimum 50 Nos per size. Single GST invoice for the complete mixed-size order. WhatsApp the size list (type, grade, M__ size, quantity per size) for pricing within 2 hours. Plain flat washers DIN 125 and spring lock washers DIN 127 in SS304 and SS316 are standard stock items — same-day or next-day dispatch from Ahmedabad.