Step twist drill

FIG. 1 is a top perspective view of a step twist drill, showing my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is an enlarged plan view of the top surface;

FIG. 8 is an enlarged plan view of the bottom surface;

FIG. 9 is an enlarged detail view of area 9 in FIG. 1 ; and,

FIG. 10 is an enlarged detail view of area 10 in FIG. 2 .

The dash-dot-dash broken lines encircling the enlarged views are for annotative purposes only and form no part of the claim thereof.