TVS Plain Hole Circular Washers, IS 6649 – M16 to M36, hardness 35 to 45 HRC

TVS Sundram Fasteners Plain Hole Circular Washers, IS 6649 are hardened plain washers made by Sundram Fasteners Limited to IS 6649, for bolt sizes M16 to M36, hardened to 35 to 45 HRC, supplied in zinc phosphate and 4 plated or coated finishes (listed below). They are the washers of the IS 3757 / IS 6623 HSFG set: each carries the preload of the bolt without embedding into the plate and gives the nut a hard, flat seat.

This item is supplied at a price on request; tell us the sizes, hardness and finish you need and we will quote.

Jai Enterprises is an authorised distributor of TVS Sundram Fasteners high tensile fasteners and supplies them from Bhilai and Raipur all over Chhattisgarh - Bhilai, Raipur, Durg, Korba, Bilaspur, Raigarh, Jagdalpur, Kanker, Ambikapur and every other district - and across India.

Is this the right one for you?

Check these three things before you order:

• Your bolt size is within M16 to M36.
• You want a plain flat washer under the nut or bolt head; spring, tab and serrated washers are not in this range.
• You are using HSFG bolts to IS 3757 with nuts to IS 6623 and need the matching hardened washer (35 to 45 HRC).

At a glance

• Brand: TVS Sundram Fasteners (Sundram Fasteners Limited, TVS group)
• Product: Plain Hole Circular Washers, IS 6649
• Standard: IS 6649
• Sizes: M16 to M36
• Hardness: 35 to 45 HRC
• Material: Steel
• Surface finish: zinc phosphate, trivalent iridescent, trivalent white, hot dip galvanised and zinc flake coating (Geomet / Magni / Delta)
• Price: price on request - tell us the sizes, hardness and finish
• Supplied by: Jai Enterprises, Bhilai and Raipur - to every district of Chhattisgarh and across India, +91 9340081159

Specifications and dimensions

• Standard: IS 6649
• Material: steel, hardened and tempered to the stated hardness
• Hardness: 35 to 45 HRC
• Surface finish options: zinc phosphate, trivalent iridescent, trivalent white, hot dip galvanised and zinc flake coating (Geomet / Magni / Delta)
• M16: inner diameter 18.00 to 18.43 mm, outer diameter 32.40 to 34.00 mm, thickness 3.10 to 4.60 mm
• M20: inner diameter 22.00 to 22.52 mm, outer diameter 40.40 to 42.00 mm, thickness 3.10 to 4.60 mm
• M22: inner diameter 24.00 to 24.52 mm, outer diameter 42.40 to 44.00 mm, thickness 3.40 to 4.60 mm
• M24: inner diameter 26.00 to 26.52 mm, outer diameter 48.40 to 50.00 mm, thickness 3.40 to 4.60 mm
• M27: inner diameter 30.00 to 30.52 mm, outer diameter 54.10 to 56.00 mm, thickness 3.40 to 4.60 mm
• M30: inner diameter 33.00 to 33.62 mm, outer diameter 58.10 to 60.00 mm, thickness 3.40 to 4.60 mm
• M36: inner diameter 39.00 to 39.62 mm, outer diameter 70.10 to 72.00 mm, thickness 3.40 to 4.60 mm
• Source: SFL's technical product catalogue (September 2026 edition) and SFL's digital product catalogue; dimensions in mm

Why choose TVS Sundram Fasteners

• Made by Sundram Fasteners Limited, a TVS group company making high tensile fasteners since 1966: first Indian company with ISO 9000, IATF 16949:2016 certified, Deming Prize 2018 for 17 plants.
• Every lot is backed by a BIS, NABL and ISO/IEC 17025 certified laboratory - tensile, fatigue, torque-tension, salt spray and coating thickness testing - as described in SFL's technical product catalogue (September 2026 edition).
• Made to a named standard - IS 6649 - with the dimensions published in SFL's technical catalogue, so parts interchange with any other maker's to the same standard.
• A choice of finishes - zinc phosphate, trivalent iridescent, trivalent white, hot dip galvanised and zinc flake coating (Geomet / Magni / Delta) - from plain indoor use to hot dip galvanised and zinc flake coating for outdoor and corrosive service.

How to choose and fit

1. Choose the washer for the bolt size; use it under the nut and, where the design or the set standard says so, under the bolt head as well.
2. Use it only with the bolting system it belongs to: the IS 6649 washer with IS 3757 / IS 6623 HSFG sets, the EN 14399-6 and DASt 021 washers with EN 14399 HV / HR and tension control sets.
3. Fit the washer under whichever element turns during tightening; a chamfered washer goes with its chamfer towards the bolt head under the head, or towards the nut under the nut, so that it clears the under-head radius.

Where it is used

• steel bridges, flyovers and plant structures bolted with IS 3757 HSFG sets
• transmission towers and substations
• pre-engineered buildings and crane girders

Other versions and series

• TVS Sundram Fasteners Plain Washers, ISO 7089 (200 to 300 HV) - M4 to M64, price on request
• TVS Sundram Fasteners Plain Washers, ISO 7089 (300 to 370 HV) - M4 to M64, price on request
• TVS Sundram Fasteners Plain Washers Large Series, ISO 7093-1 (200 to 300 HV) - M4 to M36, price on request
• TVS Sundram Fasteners Plain Washers Large Series, ISO 7093-1 (300 to 370 HV) - M4 to M36, price on request
• TVS Sundram Fasteners Chamfered Washers, DIN EN 14399-6 - M12 to M36, price on request
• TVS Sundram Fasteners Chamfered Washers, DASt 021 - M39 to M72, price on request

Related products

• TVS Sundram Fasteners Hex Head Bolts, ISO 4014 metric - the bolts these washers go under
• TVS Sundram Fasteners Hex Nuts, ISO 4032 metric - the nuts they seat
• TVS Sundram Fasteners HSFG Bolts, IS 3757 - HSFG bolts
• TVS Sundram Fasteners Tension Control Bolt Assembly - tension control bolts

Frequently asked questions

What is the price of Plain Hole Circular Washers, IS 6649?

It is supplied at a price on request. Send the sizes, grade, finish and quantity to Jai Enterprises on +91 9340081159 and we will quote from the current SFL list.

Can I use a plain washer instead?

Not in a friction grip joint. The IS 6649 washer is hardened to 35 to 45 HRC so that the full preload of the HSFG bolt is carried without the washer embedding; a plain 200 HV washer would lose preload. Use the complete IS 3757 / IS 6623 / IS 6649 set.

Are TVS Plain Hole Circular Washers, IS 6649 available in Chhattisgarh?

Yes. Jai Enterprises, an authorised distributor of TVS Sundram Fasteners, supplies from Bhilai and Raipur all over Chhattisgarh and across India. Call +91 9340081159 or use the enquiry form.

Can I get a different finish or a non-listed size?

Yes. The standard finishes are zinc phosphate, trivalent iridescent, trivalent white, hot dip galvanised and zinc flake coating (Geomet / Magni / Delta); other finishes and sizes or lengths outside the range are quoted on enquiry from SFL.

How to order

Call Jai Enterprises on +91 9340081159 or send an enquiry with the sizes, hardness, finish and quantity of Plain Hole Circular Washers, IS 6649 you need; they are supplied at a price on request. We supply from Bhilai and Raipur all over Chhattisgarh - Bhilai, Raipur, Durg, Korba, Bilaspur, Raigarh, Jagdalpur, Kanker, Ambikapur and every other district - and across India.