HHIP 1001-0731 31 Piece TPBN Indexable Boring Bar Set Use TPGB, TPGH Inserts; 31 Piece set Includes 4 pc Boring Bars, 20 pc Carbide Inserts, & 4 pc Torx Screws, 2 pc Torx Keys, Fitted Case; Clearance angle of the insert, in relation to cutting edge, gives best micro finish Small hole Capacity to a minimum of .430"The positive insert with advanced chip breaker design allows for heavier cuts 31 Piece set Insert pocket has been scientifically designed to eliminate vibration and maximize the depth of cut.; Use TPGB, TPGH Inserts The positive insert with advanced chip breaker design allows for heavier cuts