Hex Flange Seal Bolts with Under Head Seal

Hex Flange Seal Bolts with Under Head Seal are an all-in-one sealing solution often used in place of traditional gaskets. They host a unique sealing element that is permanently attached to the bearing surface of the fastener.

The highly durable green seal gets compressed during installation, filling the gap between the bearing surface and mating surface. This creates a secure gasket-type seal designed to prevent the leakage of fluids and gases under pressure.

These components offer excellent resistance to a wide range of chemicals and automotive fluids – including alcohol, gasoline, kerosene, oil, diesel fuel and hydraulic fluids – while also preventing galvanic corrosion between dissimilar materials.

Hex Flange Seal Bolts with Under Head Seal typically conform to DIN 6921 / DIN 1665 standard and are available as a partially threaded bolt or a fully threaded set screw – with or without serrations under the head. They provide a cost-effective alternative to standard o-ring seal bolts and can be supplied with a much shorter lead time.

The seal can be applied to all of our standard materials, including Steel and Stainless Steel, with non-standard materials and finishes available on request. Special seal colours can also be supplied.

Available at Fastenright in thread sizes M5 to M10, with lengths up to 100mm.

Non-standard sizes, materials and finishes are available to order as specials, including small volume manufacture, modifications and bespoke parts made to drawings. Minimum order quantities apply.

Our full range of Sealing Fasteners can be found here.

8mm
10mm
12mm
16mm
20mm
25mm
30mm
35mm
40mm
45mm
50mm
55mm
60mm
65mm
70mm
80mm
90mm
100mm

= Available Size not listed? Please make an enquiry – we may be able to provide it.