Bohrer

摘要

A cutting tool or drill bit (10) has a shank (12) with two ends. A chucking end (14) is on one end of the shank (12) and a cutting end (16) is on the other end of the shank (12). At least one flute (30) is formed on the shank (12) between the chucking (14) and cutting ends (16. The flute (30) includes a web (36) and a debris channel (32). The web (36) includes a first (38) and second (40) surface continuous with a debris channel side wall (34). The first surface (38) is substantially parallel to the shank longitudinal axis (18) and the second surface (40) is on an angle from about 100 DEG to about 120 DEG with respect to the shank longitudinal axis (18). The second surface forms the base of the debris channel or groove (32) with the debris channel side wall (34). The debris channel side wall (34) is on an angle from about 10 DEG to about 20 DEG with respect to the shank longitudinal axis (18). A ratio exists between the axial length of the first surface to the axial length of debris channel surface of about 2:1 to about 4:1. Also disclosed is a method of cold rolling a blank (60) to form the above drill bit (10).