ROCK DRILLING PRESS

摘要

A rock drilling tool including a tip formed of a hard material and provided at one end of the tool stem and a shank provided at an opposite end of the stem and having a plurality of entrain grooves extending up to a free end surface of the shank , with an entire recessed surface of an entrain groove being larger than an entire out er surface of a groove-forming rest web, and with a mean rest cross-sectional area, which is measured within an axial section of the drilling tool having a leng th at least equal to a product of a natural logarithm base and a stem diameter, deviatin g from a mean rest cross sectional area along the entire tool length maximum by 20%.< /SDOAB>