Reversible conuntersink

A hand-operated countersink adapted for the deburring of inner and outer rims of holes comprising:

• (a) a substantially flat symmetrical cutting insert provided with a central transverse hole wherein the cutting insert is substantially of isosceles triangular shape, said insert having four cutting edges substantially along the two ends of the two equal sides of the triangle, wherein the height of said triangle is substantially equal to the diameter of the shaft holding said cutting insert;
• (b) a shaft provided with a longitudinal slot at one end thereof the width of said slot being slightly larger than the width of said cutting insert;
• and
• (c) cylindrical support means for said cutting insert fixedly attached to the end of the shaft transversal to said slot allowing rotation of said shaft to assume various positions of said blade relative to said shaft.