... "2)Best quality and low price 3)Longer drilling intervals4) API &ISO TCI Tricone Bits 415 Soft Formation TCI Tricone Bits1 ... )The FL 415 tci bits are used to drill low compressive strength, very soft formations.2)TCI bits maximize ... AvailableSize: 5 7/8",6",6 1/2",7 1/2",7 7/8",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4",14 ...