MALE PORTION, DRILL BIT AND THREADED JOINT FOR PERCUSSIVE ROCK DRILLING

摘要

According to the present invention a male portion (10) for percussive rock drilling is provided comprising sections of reduced cross-sectional areas, at least one thread (12) for percussive rock drilling provided at a portion (16) at an end of the male portion. The end of the male portion comprises an abutment surface (14) for transfer of impact waves. The length (L) of the portion (16) is defined as the length of a cylinder (C), from a plane (P) of the impact surface, that touches the external diameter (Dy) of the thread, wherein said length (L) divided by the external diameter of the cylinder lies within the interval of 1-2. The intervention further relates to a drill bit and a threaded joint.