Diplomska naloga predstavlja vpliv tolerance izvrtine pri vijačenju samovreznega vijaka. V prvem poglavju je predstavljeno orodje za masovno proizvodnjo, kjer so predstavljene razlike med njimi za vijačenje tega tipa vijakov. V teoretičnem delu diplomske naloge je predstavljeno tehnično ozadje med vijačenjem samovreznega vijaka. V praktičnem delu se je iz širšega izbora premerov izvrtin določilo optimalne izvrtine za izbrane vijake. S pomočjo natančnega servo-vijačnika se je opravilo meritve in na podlagi krivulj določilo idealno izvrtino, ki smo jo nato primerjali s tisto, ki jo priporoča dobavitelj.The present diploma thesis deals with the influence of bore tolerance at screwing of self-tapping screw. In first section a tool for mass production is presented, where the differences between tools for screwing of this type of screws are described. In theoretical part of diploma thesis the theoretical background for screwing of self-tapping screw is presented. In practical work the optimal bores for selected screws were determined from a wider selection of bore diameters. By using a precise servo-screwdriver the measurements were done and based on the curves the optimal bore was determined, which was later compared with the bore as recommended by the supplier