Tools and products for bending and end forming tube and pipe

Comprehensive range of services in the development, design and manufacture of tools, including customer support and advice

Bend die

The Bend Die is a tool, a mold, which allows tubes to be bent around it and defines the results shape of the bent tubes.


The size of the groove will depend upon the outside diameter (OD) and the center line radius (CLR) the maximum degree of bend (DOB).. These parameters then have a major impact on the size and shape of the bend die.

The bend dies are most commonly bolted down. It is also possible to fix it directly to the machine using flanges. The die is usually fixed using a key.

Gripping section

The length of the gripping part of the bend die is dependent on the parameters of the tube and usually has a special surface treatment to help in gripping the tube during the bend. This part is often made separately and attached to the bend die.

The surface of the clamp has a significant influence on the functioning of the tools. There are 5 basic surface types.

Smooth surface
The least useful, but sometimes necessary variant from a construction perspective, is a groove with no surface treatment. This variant is used in applications where it is necessary to take care of the visual quality of the surface of tube. The disadvantage of this is the need to use long clamps so that there are no markings on the pipe from gripping This option is used, for example in furniture making.

Grit blasted
This treatment is a gentle roughing of the functional surface of the clamp. Compared to the smooth surface, this method doesn't particularly affect the length of the clamps. While we don't need to extend the clamps, we can't shorten them either. The advantage of grit blasted clamps are that they do not lower the quality of the outer surface of the tubes after gripping.

Another way we can treat the surface of the groove, with a carbide- based electric arc spray. This allows us to achieve a greater roughness and also to reduce the diameter of the clamp by 0.1 to 0.2 mm. That's why we recommend producing the diameter of the groove at the nominal diameter of the tube. This has a positive effect on the gripping surface of the and allows us to shorten the length of the clamp.

The surface treatment is a machined serrated surface of the groove. The main advantage of this surface treatment is that is allows us to significantly reduce the clamp length. The coarseness of the serration is chosen for the diameter of the tube. It is set by the number of teeth per inch. Typically we would have 12, 16, 20 or 25 teeth / inch.

This treatment is typically very course. It does leave small marks on the pipe, how this allows for the length of the clamp to be significantly reduced. We have 3 levels of coarseness, 12, 16 or 20-teeth/ inch depending on the diameter of the tubes, from 30 to 140 mm. The disadvantage of this solution is that it can only used for straight clamps, or on straight parts of shaped clamps using insert.