5 Piece 1/4-1" 82 Degree High Speed Steel Countersink Set ~ For portable and machine work when operated at comparatively high speeds. ~ Single flutes will countersink holes much smaller than multi-flute tools. ~ Set includes 1/4", 3/8", 1/2", 3/4". & 1". ~ The 1/4" has a 1/4" shank and a 1-1/2" overall length. ~ The 3/8" has a 1/4" shank and a 1-3/4" overall length. ~ The 1/2" has a 1/4" shank and a 2-1/8" overall length. ~ The 3/4" has a 1/2" shank and a 2-11/16" overall length. ~ The 1" has a 1/2" shank and a 2-13/16" overall length.