Trustworthy data about cutting tool temperature distribution is main importance in drilling processes. In this paper, the effects of drilling depth, spindle speed and feed rate on the drill bit temperature experimentally have been investigated in step-by-step and continuous dry drilling. Drill temperatures were measured by inserting standard thermocouples through the coolant (oil) hole of TiN/TiAlN coated carbide drills. Experimental studies have been conducted by using two different workpiece materials, AISI 1040 steel and Al 7075-T651. (C) 2004 Elsevier Ltd. All rights reserved.