Abstract: A cutting tool has an insert shaped as a parallelogram that is detachably mounted by a clamp screw 4 on a tip mounting face of a holder. Concave grooves are formed like parallel stripes on the tip mounting face of the holder, and convex lines are formed on the abdominal face of the insert to be fitted in the concave grooves, so that the insert is clamped by the clamp screw to the holder in a state where the convex lines are fitted in the concave grooves on the tip mounting face.

Abstract: A cutting tool is provided which comprises an end cutting edge at an end of a rake face, and a depression formed in the rake face so as to provide the end cutting edge with a concave edge portion.

Abstract: A cutting tool is disposed on a turret. The cutting tool includes: a holder having a peak end, and a throw-away insert clamped to the peak end of the holder with a clamp screw. The holder has a bottom face and a peak end face defining a corner of the holder. The corner of the holder forms a chamfered face. The throw-away insert has a bottom face and a relief face defining a corner of the throw-away insert. The corner of the throw-away insert forms a chamfered face. The chamfered face of the corner of the holder and the chamfered face of the corner of the throw-away insert prevent the cutting tools adjacent to each other from causing an interference with each other when the cutting tools are at least one of in a standby position and in a machining operation.

Abstract: The tip having a basic form of parallelogram that is detachably mounted by a clamp screw 4 on a tip mounting face 2a of a holder 2, characterized in that two or more concave grooves 6 are formed like parallel stripes on the tip mounting face 2a of the holder 2, and two or more convex lines 7 are formed on its own abdominal face to be fitted in the concave grooves 6, in which the insert is clamped by the clamp screw 4 in a state where its own convex lines 7 are fitted in the concave grooves 6 on the tip mounting face 2a.

Abstract: A cutting tool is provided which comprises an end cutting edge at an end of a rake face, and a depression formed in the rake face so as to provide the end cutting edge with a concave edge portion.

Abstract: A cutting tool is disposed on a turret. The cutting tool includes: a holder having a peak end, and a throw-away insert clamped to the peak end of the holder with a clamp screw. The holder has a bottom face and a peak end face defining a corner of the holder. The corner of the holder forms a chamfered face. The throw-away insert has a bottom face and a relief face defining a corner of the throw-away insert. The corner of the throw-away insert forms a chamfered face. The chamfered face of the corner of the holder and the chamfered face of the corner of the throw-away insert prevent the cutting tools adjacent to each other from causing an interference with each other when the cutting tools are at least one of in a standby position and in a machining operation.

Abstract: A cutting tool is disposed on a turret. The cutting tool includes: a holder having a peak end, and a throw-away insert clamped to the peak end of the holder with a clamp screw. The holder has a bottom face and a peak end face defining a corner of the holder. The corner of the holder forms a chamfered face. The throw-away insert has a bottom face and a relief face defining a corner of the throw-away insert. The corner of the throw-away insert forms a chamfered face. The chamfered face of the corner of the holder and the chamfered face of the corner of the throw-away insert prevent the cutting tools adjacent to each other from causing an interference with each other when the cutting tools are at least one of in a standby position and in a machining operation.

Abstract: A cut-off insert (1) used for cutting-off a piece from a work, comprising an end-cutting face (17); at least two flat rake faces (16) running approximately in parallel and forming at least two straight end-cutting edges (15) with the end-cutting face (17); a recessed end-cutting edge (25) formed between the straight end-cutting edges (15); a sloped breaker wall (18) extended and sloping from the flat rake faces (16) to a clamp-pressing face (29) of the cut-off insert (1); and a recessed rake face having a groove (26) extending from the recessed end-cutting edge (25) toward a clamp-pressing face (29) and formed between the flat rake faces (16).