Rotary Draw Bending is the most complex form of bending and requires a toolset to execute. The tube is held by the clamp and pressure die, and rotated around the bend die. A mandrel and wiper support the inside and outside of the tube and help prevent wrinkles or flattening. The basic set of tools is therefore the Mandrel, Wiper die, Bend die, the Clamp die and the Pressure die.
To increase the life of the tools it is necessary to properly lubricate them. This will reduce vibrations and induction of heat at the bending points. Choosing an appropriate gel or fluid depends on:
- The material of the tubes and machines
- The volume of production
- Other processing
- The use of the bent tubes (For example, the method of cleaning or the eventual heat processing)
It is important to clean the individual tubes before bending.