Today, the largest share in machining processes refers to metalworking. At the same time, working technologies of non-homogeneous materials such as stone and composites are increasingly being explored. The properties of non-homogeneous materials are not equal through the entire volume of the observed body and that problem affects the working process and the tool wear. In the first part of this paper, the methods of calculation of powers, moments, and forces at drilling will be explained. The mechanisms and different types of tool wear that may occur due to the different cutting conditions in which the tool is located during cutting process will be displayed. Taylor’s model of tool wear and how the tool life is defined will be described. The purpose of cutting fluids (cooling lubrication fluid, coolant), which types and ways of bringing the coolant exist will be shown. At the end of first part, the Sinker Electrical Discharge Machining (Sinker EDM, Ram EDM) process, which is needed for modifying a commercial drill bit for experiment, will be explained. The experimental section of this paper explains the method of modifying a commercial drill bit with a hard solder plate, in such way that through the drill a channel is created which allows the flow of cutting fluids during drilling. Drilling of different types of stones will be carried out with different process parameters and the different degree of tool wear. Compressed air will be used during drilling to help extract a chip from the inside of the bore and cool the cutting edge of drill bit. During the experiment, the signals of cutting forces and the current of the drive motors will be recorded. Also, according to the plan of the experiment, the flank face of drill bit will be photographed using an industrial camera. At the end, the obtained results will be compared with the results of the same drilling processes carried out without using a compressed air as cutting fluid.