TVS Hex Flange Bolts, DIN 6921 – M6 to M20, grades 8.8 and 10.9

TVS Sundram Fasteners Hex Flange Bolts, DIN 6921 are hexagon flange bolts made by Sundram Fasteners Limited to ASME B18.2.3.9M (Except M10) / DIN 6921, in sizes from M6 to M20, property classes 8.8 and 10.9, supplied in zinc phosphate and 4 plated or coated finishes (listed below). The flange under the head works like a built-in washer: it spreads the clamping load over a larger area and protects the surface, so no separate washer is needed. They are partially threaded, with a plain shank under the head, made by cold forging, with the TVS mark and the grade mark on the head.

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 M6 to M20.
• You want to drop the separate washer: the plain flange spreads the load like a built-in washer (it is not a locking feature - use a SunLoc or prevailing torque nut where vibration is the concern).
• One of the property classes 8.8 or 10.9 covers your load.

At a glance

• Brand: TVS Sundram Fasteners (Sundram Fasteners Limited, TVS group)
• Product: Hex Flange Bolts, DIN 6921
• Standard: ASME B18.2.3.9M (Except M10) / DIN 6921
• Sizes: M6 to M20
• Head form: Hexagonal with Flange
• Drive: Hexagon
• Property class: 8.8 and 10.9
• Material: Steel
• Surface finish: zinc phosphate, trivalent iridescent (8.8 & 10.9), trivalent white (8.8 & 10.9), hot dip galvanised (8.8 & 10.9) and zinc flake coating (Geomet / Magni / Delta)
• Forging: cold forging
• 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: ASME B18.2.3.9M (Except M10) / DIN 6921
• Material: high tensile steel; property classes to ISO 898-1
• Property class: 8.8 and 10.9
• Class 8.8 (ISO 898-1, as tabulated in SFL's catalogue): tensile strength 800 MPa nominal (830 MPa minimum above 16 mm), 0.2 % proof stress 640 MPa nominal (660 MPa minimum above 16 mm), elongation 12 % minimum, hardness 230 to 300 HV (255 to 336 HV above 16 mm)
• Class 10.9 (ISO 898-1, as tabulated in SFL's catalogue): tensile strength 1,000 MPa nominal, 1,040 MPa minimum, 0.2 % proof stress 900 MPa nominal, 940 MPa minimum, elongation 9 % minimum, hardness 310 to 382 HV
• Surface finish options: zinc phosphate, trivalent iridescent (8.8 & 10.9), trivalent white (8.8 & 10.9), hot dip galvanised (8.8 & 10.9) and zinc flake coating (Geomet / Magni / Delta)
• Manufacture: cold forging
• Marking: TVS brand mark on the head and the property class mark
• M6: pitch 1.0; across flats 10.00 mm, across corners 10.95 mm, head height 6.60 mm; lengths 25 to 60 mm
• M8: pitch 1.25; across flats 13.00 mm, across corners 14.26 mm, head height 8.10 mm; lengths 35 to 150 mm
• M10: pitch 1.5; across flats 15.00 mm, across corners 16.50 mm, head height 9.20 mm; lengths 40 to 200 mm
• M12: pitch 1.75; across flats 16.00 mm, across corners 17.62 mm, head height 11.50 mm; lengths 45 to 120 mm
• M14: pitch 2.0; across flats 18.00 mm, across corners 19.86 mm, head height 12.80 mm; lengths 50 to 120 mm
• M16: pitch 2.0; across flats 21.00 mm, across corners 23.15 mm, head height 14.40 mm; lengths 55 to 160 mm
• M20: pitch 2.5; across flats 27.00 mm, across corners 29.87 mm, head height 17.10 mm; lengths 60 to 200 mm
• Catalogue note: Threaded length TL = 2D + 6 for lengths up to 125 mm, 2D + 12 for 130 to 200 mm and 2D + 25 for lengths above 205 mm (D = thread diameter), as printed on the SFL table
• 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 - ASME B18.2.3.9M / DIN 6921 - 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 (8.8 and 10.9), so site inspection is simple.
• A choice of finishes - zinc phosphate, trivalent iridescent (8.8 & 10.9), trivalent white (8.8 & 10.9), hot dip galvanised (8.8 & 10.9) 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. Pick the thread series and size from the drawing or the mating part: measure the diameter and pitch (or threads per inch) rather than guessing.
2. Choose the length: add the grip (total thickness clamped) to the nut height plus two or three threads, and check from the threaded-length note that the plain shank does not run into the nut.
3. Choose the property class the designer specified: 8.8 is the general-purpose class, 10.9 for higher clamp loads in the same size.
4. Choose the finish for the environment: zinc phosphate for indoor or oiled use, trivalent zinc plating for mild exposure, hot dip galvanising or zinc flake coating for outdoor and corrosive sites.
5. Tighten to the torque the design calls for; no washer is needed under the flanged head, and a washer under the nut is only needed where the face is soft or slotted. Use a nut of matching class.

Where it is used

• automotive engines, chassis and body assemblies
• two-wheeler and tractor assemblies
• enclosures, panels and sheet-metal parts
• pumps, motors and compressors
• agricultural and construction equipment

Other versions and series

• TVS Sundram Fasteners Hex Flange Bolts, ISO 4162 - M6 to M12, price on request
• TVS Sundram Fasteners Hex Flange Bolts, DIN 1665 - M10 to M20, price on request
• TVS Sundram Fasteners Hex Flange Bolts, JIS B1189 - M6 to M16, price on request

Related products

• TVS Sundram Fasteners Hex Nuts, ISO 4032 metric - hex nuts for flange screws and bolts
• TVS Sundram Fasteners SunLoc Nylon Insert Nuts, DIN 982 / ISO 7040 - nylon insert nuts for vibration

Frequently asked questions

What is the price of Hex Flange Bolts, DIN 6921?

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 do the property classes 8.8 and 10.9 mean?

They are ISO 898-1 strength classes. The first number is the nominal tensile strength in hundreds of MPa (the minimum is a little higher: 830 MPa for 8.8 above M16 and 1,040 for 10.9) and the second the ratio of yield to tensile: 8.8 is 800 MPa tensile with 640 MPa yield and 10.9 is 1,000 MPa with 900 MPa yield (nominal values). A higher class carries more clamp load in the same size, and needs a nut of matching class.

Do I still need a washer with a flange screw or bolt?

No. The flange under the head does the job of a washer: it spreads the load over a larger area and protects the surface. That saves a part and a step on the assembly line.

Which flange standard should I choose?

ISO 4162 / DIN 1662 (small series), DIN 1665 (heavy series, with a larger flange) and DIN 6921 / ASME B18.2.3.9M differ in the flange diameter and head height, and JIS B1189 is the Japanese series used on many two-wheelers and cars. Match the standard on your drawing or the part you are replacing; the dimension table above gives each size.

Are TVS Hex Flange Bolts, DIN 6921 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 (8.8 & 10.9), trivalent white (8.8 & 10.9), hot dip galvanised (8.8 & 10.9) 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 Hex Flange Bolts, DIN 6921 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.