Milling cutter

A rotary cutting tool for cutting V-shaped notches in key blanks, characterized by:

• A. circumferentially spaced peripheral teeth on the tool adapted to form the bottoms of notches in a key blank;
• B. circumferentially spaced side cutting teeth on opposite sides of the tool at the peripheral portion thereof;
• C. the cutting edges of the cutting teeth at the opposite sides of the tool being in outwardly convergent relation to one another, toward and to said peripheral teeth so as to be cooperable therewith in the cutting of substantially V-shaped notches in a key blank;
• D. and the cutting edges of the teeth at one side of the tool having substantially slight convex curvature that changes gradually but continuously from a substantially zero rare at the outer extremities of said teeth to a positive rake at the inner extremities of said teeth, said convex cutting edges lying on the surface of a cone which is concentric with the axis of rotation of the tool.