Abstract: A drilling tool for use in the tool holder of a drilling machine includes a drilling member and a holder input unit laterally enclosing the end of the drilling member which fits into the tool holder. The holder input unit is hollow and is non-rotatably connected to the drilling member. The input unit consist of an outer sleeve having a large radially outer surface spaced outwardly from the drilling member and webs extending between the drilling member and the sleeve. The outer surface of the sleeve is generally polygonal in cross section transverse to the axis of the drilling member and is shaped to fit into and contact the tool holder. The webs and sleeve of the holder input unit effect the transmission of heat from the drilling member.