Patent ID: 6371702
Filing Date: 2002-04-16
Classification: B23B,Y10S,Y10T

Abstract:
A spade drill comprising:a spade blade holder having a recessed portion and a pin on an upper surface of said recessed portion; a spade blade affixed to said spade blade holder, said spade blade having a longitudinal cutting axis and a recess on a bottom surface for accepting said pin opposing side faces, lands and point surfaces formed along a point edge, said point surfaces including a primary relief surface and a secondary relief surface, said primary relief surface and said secondary relief surface intersecting and extending from an apex of said point edge to an intersection of said land and said side face; wherein said spade blade has at least one web thinning notch, said at least one notch having a hook edge with a hook length and a lip edge with a lip length, wherein the lip length to hook length ratio of said notch is about 1 to about 1&frac13;.