Patent ID: 6192875
Filing Date: 2001-02-27
Classification: B28D

Abstract:
A core bit comprising:a tube (2) extending in an axial direction and terminating in said axial direction at an end of said tube, wherein said end has an opening end surface (21); anda plurality of tips (3) fixed to said opening end surface (21) of said tube (2), whereineach one of said tips (3) includes an abrasive grain layer (31) that comprises diamond abrasive grains and a binder bonding said diamond abrasive grains to each other,wherein said diamond abrasive grains contain diamond and not more than 0.03 weight % of inclusions, which contain iron and nickel as main components thereof, andwherein said binder contains at least 0.1 weight % and not more than 2.0 weight % of graphite.