Centre Drill

When drilling metal, it is advisable first to mark the hole centre with a Centre Punch to stop Twist Drills wandering about the surface.

When drilling down the centre of a bar held in a Lathe chuck however, a Centre Drill can be used. These are short and rigid enough to mark the bar centre and drill a small pilot hole. Also known as Slocombe Drills they are used also to create the countersink required to locate a tailstock centre when turning between centres - which is the purpose for which they were originally designed.