Patent ID: 8720613
Filing Date: 2014-05-13
Classification: B24B,C21D,C22C,E21B

Abstract:
1. A drill bit ( 10 ) for a rock drilling tool ( 12 ), which drill bit ( 10 ) has a drilling surface ( 10 b ) that is arranged to contact rock during drilling, wherein a longitudinal cross section ( 10 t ) of the drill bit ( 10 ) through the drilling surface ( 10 b ) exhibits the following relationships of L tot (depth)/L tot (5.0) and H(depth)/H(5.0) at the specified depths, where H(depth)/H(5.0) is measured according to a Vickers test and L tot (depth)/L tot (5.0) is measured according to the Palmqvist method described in this document substantially along the drill bit's longitudinal axial centre line (C): if the drill bit ( if the drill bit (