The Dormer Countersink drill bit is available with tri flat shank. A 90 degree countersink designed for chamfering standard fastener holes and removing burrs from drilled holes. Shank with three ground flats gives improved holding in three jaw chucks, especially when using in hand held power tools. Titanium aluminium nitride coating extends tool life. Suitable to chamfer holes in many materials. Cylindrical Shank with 3 flat
High speed steel tool material
Right hand rotation and cutting
DIN 335 C Straight shank countersink standards