During the frictiondrilling process, the material glows light-red and the Drabus frictiondrill itself should glow dark-red. So, the tool holder has two functions. The first function is to clamp the Drabus frictiondrill. The Drabus frictiondrill does not centre itself. From the moment that the Drabus frictiondrill makes contact with the cold workpiece surface, it has the tendency to walk sideways. So, the position of the Drabus frictiondrill should be determined by the rigidity of the machine and the precision of the rotation of the tool holder and the machine. The second function of the tool holder is to discharge the generated friction heat. This is necessary to prevent the friction heat from warming up the spindle and the bearings of the drilling machine. The outside cooling is a fixed part of the tool holder and is able to discharge the heat in a continual or interrupted process.
The correct use of the collet is very important. Before putting the collet into the tool holder, the collet must first be put into the coupling nut.
After that, the coupling nut and the collet must be assembled together into the tool holder. Before tightening the coupling nut, the shank of the Drabus frictiondrill must be put into the collet with the collar against the outside of the collet. The coupling nut must be tightened firmly with the correct tool. Remark: All the tangent planes, namely the inside (spindle) and outside (tool holder) tapers, have to be cleaned before assembling the parts.