Analysis of Crack Deffect at Nut M 14 Cold Forging Process with FTA Methode

Forming technique by cold forging is considered the easiest and simplest technique but in the implementation there are problems with the end result of nut formation type M14 with SWCH45K material in the form of cracks on the surface. To find out the cause of cracks in the cold forging production process, analysis of failure is done with the Fault Tree Analysis method, the variables carried out in implementing the Fault Tree Analysis analysis method, data collection, test initial material characteristics to determine the mechanical properties, metallographic testing to determine the quality of the initial material, calculation of force, stress, strain. The results of the force calculation show that crack defects are caused by high stress / stress concentrations in the station 3 formation process because the punch corner has no radius (rounding). The conclusion of the analysis of the root of the problem of crack defects in the process of forming cold forming M14 nuts was due to the punch design tool not having a radius profile. The results of these data collection and testing variables were applied in the failure tree diagram, so it was concluded that the cause of the M14 nut cold forging crack was design tools punch