a tool has a tool body which defines a first seat into which is secured an anvil . the anvil and the tool body define a second seat into which a backup plate is located . the backup plate has a longitudinally extending groove which is used to locate a form tool cutting insert . a first clamp assembly exerts a clamping force on the insert and backup plate against the anvil in a first direction . a second clamp assembly exerts a clamping force on the insert and backup plate against the anvil in a second direction , the second direction being approximately 90 ° to the first direction . the insert has a cutting surface of a predetermined configuration on two opposite sides such that indexing of the cutting insert 180 ° will position the opposite cutting surface in the machining ready position . the backup plate has a complementary predetermined configuration to support each of the cutting surfaces of the insert . the clamping of the insert and backup plate against the anvil in two directions approximately 90 ° apart , enables a more accurate positioning of the insert and reduces the need for running set - up parts after each insert change or indexing .