A device for the quick change of tool holder adapters, especially for use on CNC machine tools such as multi-spindle or single-spindle lathes, turning and milling centres, transfer machine tools, for orienting and clamping the different tool holder shanks in the appropriate seats of the rotating and non-rotating shafts present in the mechanical bodies such as motorised or non-motorised tool holders, multiple or single, comprising a tool holder shank of truncated-cone shape designed to fit, starting from its smaller diameter rear part, into a complementary housing made in the rotating shaft of a motorised module. On the smaller diameter rear face of the tool holder shank a milling cut is made configured to accommodate at least one removable insert which protrudes partly frontally in the direction of a recess made on the back wall of the tapered seat of the rotating shaft of the motorized module.

A device for the quick change of tool holder adapters, especially for use on CNC machine tools such as multi-spindle or single-spindle lathes, turning and milling centres, transfer machine tools, for orienting and clamping the different tool holder shanks in the appropriate seats of the rotating and non-rotating shafts present in the mechanical bodies such as motorised or non-motorised tool holders, multiple or single, comprising a tool holder shank of truncated-cone shape designed to fit, starting from its smaller diameter rear part, into a complementary housing made in the rotating shaft of a motorised module. On the smaller diameter rear face of the tool holder shank a milling cut is made configured to accommodate at least one removable insert which protrudes partly frontally in the direction of a recess made on the back wall of the tapered seat of the rotating shaft of the motorized module.

A cutter holder structure comprises a cutter arbor and a connecting shaft having a tapered section at one end thereof. One end of the tapered section is formed with a first inner screw hole, and another end of the tapered section is formed with a second inner screw hole. The connecting shaft further has a horizontal positioning hole that penetrates through the connecting shaft. Two ends of the positioning hole are formed with cylindrical holes. A reduced hole is defined between the cylindrical holes. A nut has a third inner screw hole at one end and an axial hole at another end. The nut further has a horizontal countersink hole and a horizontal fourth inner screw hole. An eccentric distance is defined between a center of the countersink hole and a center of the fourth inner screw hole. A screw is inserted through the countersink hole and locked into the fourth inner screw hole.

A cutter fastening apparatus has a body, a collet, a cutter, and a cap. The body has an outer thread. The collet is mounted in the body and has an abutting groove formed in an outer surface of the collet and a through hole formed through a front surface of the collet. The cutter is mounted through and fixed to the through hole of the collet. The cap is screwed with the outer thread of the body and has a driving ring portion protruding from an inner surface of the cap and a balance groove formed in the inner surface of the cap and being adjacent to the driving ring portion. The cap has a clamping portion protruding from the inner surface of the cap and a holding portion protruding from the inner surface of the cap.