DRILLING TOOL

摘要

The present invention relates to a guide tube and a drill string suitable for mechanical handling in a rig for rock drilling. The guide tube (10) has an oter diameter (D) which is substantially constant along the axial extension of the tube and comrises a female thread (16) in a recess (32) in a first end (11) and a male thread (15) at a second end (13) as well as a through-going flush channel (19) to transfer fluxh medium to a rock drill bit for percussive top hammer drilling. The recess has an axial length (L1). The guide tube (10) comprises a cylindrical waist (23) in the vicinity of the first end (11). The waist (23)) has an axial extension (L2) that is longer than the axial length (L1) of the recess (32).