Male portion, drill bit and threaded joint for percussive rock drilling

摘要

A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1-2.