The deformation knurling carried out with the lathe implies great difficulties and risks: parts damaged by the jaws of the self-centering chuck for the high load, long shafts bending, short parts going out of the self-centering chuck… The most serious problem is the deterioration of the machine: working under forced load the head and screw of the carriage suffer a lot. These problems, up to now unsolved, can be settled with the new Special Godron. The radial load is completely absorbed by the device because of the two opposite rollers. It knurls any short or long part of different diameter with precision. It is strong and hardened in the parts subject to wear. It can be easily assembled. It should be tightened to the turret as a standard cutting tool. Each Godron model has a stroke of mm 30 which can be zeroed with a graduated nonius.