METHOD OF CUTTING THREAD AT PART Russian patent published in 2013 - IPC B23G1/00 B23H5/00 C25D5/00 

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and may be used for threading parts operated at sign-variable loads in conditions of abrasive media. Proposed method comprises shaping thread geometry and its thermal hardening by passing electric current through zone of contact between tool and revolving part. Note here that in tool first pass, thermomechanical finishing-hardening is made at thread base and adjoining thread turns. In tool second pass, thread profile or its separated sections are coated with copper thin layer extracted from copper-bearing solution fed in aforesaid contact zone.

EFFECT: thin copper layer prevents hydrogen wear of thread surface, decreased fatigue of threaded surfaces.