Twist drill, in particular a solid carbide twist drill

摘要

A twist drill is described, the tool life of which is to be considerably increased by special drill point grinding. This is achieved by virtue of the fact that an intermediate flank becoming narrower radially from inside to outside and extending right into the area of the respective heel is provided in each case between one of the main flanks and the flank allocated to it, and that the flanks together with the respectively adjoining intermediate flank enclose an angle of about 165@, and the intermediate flanks together with the main flank in each case allocated to them enclose a larger obtuse angle. An increase in the wedge angle bringing about an increase in the tool life is achieved by these measures.