Advances in the precision machining of small deep holes

Abstract Based on the analysis of the forces acting on a deep-hole drilling head and the understanding of the burnishing action of the carbide guide pads, an investigation of the precision drilling method of small deep holes in difficult-to-cut materials was carried out. The influence of tool geometry and cutting parameters (cutting speeds and feed rates) on the surface quality of the drilled holes was studied, the results of which indicating that O10–O20 mm small deep holes of high tolerance grades (IT7 to IT9) and lower surface roughness values ( R a ) in the range of 0.2–1.6 μm can be achieved and the problem of axial deviation of holes drilled minimised under optimised cutting parameters by means of the new/improved BTA drill.