TVS HSFG Bolts, IS 3757 – M16 to M36, grades 8.8S and 10.9S

TVS Sundram Fasteners HSFG Bolts, IS 3757 are high strength friction grip bolts made by Sundram Fasteners Limited to IS 3757, in sizes from M16 to M36, property classes 8.8S and 10.9S, supplied in zinc phosphate and 4 plated or coated finishes (listed below). HSFG bolts are tightened to a controlled preload so that the connected steel plates are clamped together and the load is carried by friction between them, not by the bolt shank bearing on the hole; that is what makes the joint slip-resistant under vibration and fatigue loading. They are made by cold forging, with hot forging for the larger sizes.

This item is supplied at a price on request; tell us the sizes, lengths, property class 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 four things before you order:

• Your thread is metric coarse pitch (M sizes).
• The size you need is within M16 to M36.
• The joint is a structural steel connection designed as a friction grip (slip-critical) joint, with the preload specified by the designer.
• You will tighten with a calibrated wrench, by the part-turn method or with load-indicating washers, as the design requires.

At a glance

• Brand: TVS Sundram Fasteners (Sundram Fasteners Limited, TVS group)
• Product: HSFG Bolts, IS 3757
• Standard: IS 3757
• Sizes: M16 to M36
• Head form: Hexagon
• Drive: Hexagon
• Property class: 8.8S and 10.9S
• Material: Steel
• Surface finish: zinc phosphate, trivalent iridescent, trivalent white, hot dip galvanised and zinc flake coating (Geomet / Magni / Delta)
• Forging: cold forging, with hot forging for the larger sizes
• Price: price on request - tell us the sizes, lengths, property class and finish
• Supplied by: Jai Enterprises, Bhilai and Raipur - to every district of Chhattisgarh and across India, +91 9340081159

Specifications and dimensions

• Standard: IS 3757
• Material: high tensile steel; bolt property classes 8.8S and 10.9S to IS 3757 / IS 1367-3
• Property class: 8.8S and 10.9S
• Surface finish options: zinc phosphate, trivalent iridescent, trivalent white, hot dip galvanised and zinc flake coating (Geomet / Magni / Delta)
• Manufacture: cold forging, with hot forging for the larger sizes
• Marking: TVS brand mark on the head and the property class mark
• M16: pitch 2.0; across flats 27.00 mm, across corners 29.56 mm, head height 10.00 mm; lengths 40 to 230 mm; threaded length 31 mm for L up to 100 mm, 38 mm above 100 mm
• M20: pitch 2.5; across flats 34.00 mm, across corners 37.29 mm, head height 12.50 mm; lengths 45 to 200 mm; threaded length 36 mm for L up to 100 mm, 43 mm above 100 mm
• M22: pitch 2.5; across flats 36.00 mm, across corners 39.55 mm, head height 14.00 mm; lengths 50 to 190 mm; threaded length 38 mm for L up to 100 mm, 45 mm above 100 mm
• M24: pitch 3.0; across flats 41.00 mm, across corners 45.20 mm, head height 15.00 mm; lengths 55 to 300 mm; threaded length 41 mm for L up to 100 mm, 48 mm above 100 mm
• M27: pitch 3.0; across flats 46.00 mm, across corners 50.85 mm, head height 17.00 mm; lengths 60 to 200 mm; threaded length 44 mm for L up to 100 mm, 51 mm above 100 mm
• M30: pitch 3.5; across flats 50.00 mm, across corners 55.37 mm, head height 18.70 mm; lengths 65 to 300 mm; threaded length 49 mm for L up to 100 mm, 56 mm above 100 mm
• M36: pitch 4.0; across flats 60.00 mm, across corners 66.44 mm, head height 22.50 mm; lengths 75 to 300 mm; threaded length 56 mm for L up to 100 mm, 63 mm above 100 mm
• Note: property classes 8.8S and 10.9S as designated by IS 3757 (SFL's catalogue writes them 8 S and 10 S; 8S and 10S are the IS 6623 nut classes)
• 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 3757 - with the dimensions published in SFL's technical catalogue, so parts interchange with any other maker's to the same standard.
• The grade mark on each part shows its property class (8.8S and 10.9S), so site inspection is simple.
• 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. Use the complete set: IS 3757 bolt, IS 6623 nut (class 8S with an 8.8S bolt, class 10S with a 10.9S bolt) and IS 6649 hardened washer (35 to 45 HRC).
2. Bring the joint plates into contact (snug tight) before final tightening.
3. Tighten to the specified preload by the method the design states: calibrated torque wrench, part-turn of the nut, or direct tension indicators.
4. Do not reuse HSFG bolts that have been fully tensioned.

Where it is used

• steel bridges and flyovers
• industrial sheds, pre-engineered buildings and plant structures
• transmission towers and substations
• crane girders and conveyor galleries
• power plant and cement plant steelwork

Related products

• TVS Sundram Fasteners HSFG Nuts, IS 6623 - the other half of the HSFG set
• TVS Sundram Fasteners Plain Hole Circular Washers, IS 6649 - the hardened washer for HSFG sets
• TVS Sundram Fasteners Tension Control Bolt Assembly - tension control bolts for shear-wrench installation

Frequently asked questions

What is the price of HSFG Bolts, IS 3757?

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.

What goes with an HSFG bolt?

A matching HSFG nut to IS 6623 (class 8S with an 8.8S bolt, class 10S with a 10.9S bolt) and a hardened washer to IS 6649 (35 to 45 HRC). Jai Enterprises supplies all three.

Are TVS HSFG Bolts, IS 3757 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, lengths, property class, finish and quantity of HSFG Bolts, IS 3757 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.