Abstract: A collet assembly of improved stability has a collet, an axial limiting assembly, a cutter, a pin, and multiple damping elements. The collet has a containing space, a pin-receiving groove, a connecting groove, and multiple receiving grooves. The containing space is formed through the collet. The pin-receiving groove is formed through the collet. The connecting groove is recessed on the collet. The multiple receiving grooves are recessed in the collet. The axial limiting assembly is mounted to the collet. The cutter has a limiting groove and a mounting end. The limiting groove is recessed on the cutter. The mounting end abuts against the limiting assembly. The pin extends into the pin-receiving groove and abuts against the limiting groove of the cutter. Each one of the multiple damping elements is received in a respective one of the multiple receiving grooves of the collet. A collet of improved stability is also provided.

Abstract: A cutter holder has a body and a retention knob connected to the body by threading. The body has a connecting hole having an internal threaded segment and a straight segment. The retention knob has a head, an abutting portion, and an external threaded portion. The abutting portion has a flange and an extending portion. The extending portion and the straight segment are in a clearance fit, and a sealing member seals the clearance between the extending portion and the straight segment. The external threaded portion is engaged with the internal threaded segment by threading, and has a first threaded segment and a second threaded segment. The first threaded segment is away from the head of the retention knob, and a tolerance class of the second threaded segment is higher than a tolerance class of the first threaded segment.

Abstract: A cutter holder has a holder, a collet, and a nut. The holder has a first threaded portion having an external thread, a first abutting surface, a second abutting surface, at least one recess, and at least one sealing member. The at least one recess is recessed in the second abutting surface. The at least one sealing member is mounted in the at least one recess and partially protrudes from the second abutting surface. The nut has a second threaded portion having an internal thread, a third abutting surface, and a fourth abutting surface. The internal thread and the external thread are corresponding internal and external trapezoidal threads, respectively. The third abutting surface and the first abutting surface have a corresponding diameter with a clearance therebetween being less than 0.015 millimeter. The fourth abutting surface and the at least one sealing member are in an interference fit.

Abstract: A cutter holder has a holder, a collet, and a nut. The holder has a first threaded portion having an external thread, a first abutting surface, a second abutting surface, at least one recess, and at least one sealing member. The at least one recess is recessed in the second abutting surface. The at least one sealing member is mounted in the at least one recess and partially protrudes from the second abutting surface. The nut has a second threaded portion having an internal thread, a third abutting surface, and a fourth abutting surface. The internal thread and the external thread are corresponding internal and external trapezoidal threads, respectively. The third abutting surface and the first abutting surface have a corresponding diameter with a clearance therebetween being less than 0.015 millimeter. The fourth abutting surface and the at least one sealing member are in an interference fit.

Abstract: A coolant collet assembly has a collet body and a cutter. The collet body has an outer end, an inner end, an annular groove, multiple external slits, multiple internal slits, and multiple coolant channels. The external slits and the internal slits are in a staggered arrangement. Each coolant channel is defined longitudinally in the collet body around the cutter hole, is converged radially toward the outer end, and has an end communicating with a respective one of the internal slits and an opening formed in the outer end. The cutter is inserted in the cutter hole. The coolant may flow through the coolant channels of the collet body and is guided to the heating point of the working cutter with the converged coolant channels.

Abstract: A coolant collet assembly has a collet body and a cutter. The collet body has an outer end, an inner end, an annular groove, multiple external slits, multiple internal slits, and multiple coolant channels. The external slits and the internal slits are in a staggered arrangement. Each coolant channel is defined longitudinally in the collet body around the cutter hole, is converged radially toward the outer end, and has an end communicating with a respective one of the internal slits and an opening formed in the outer end. The cutter is inserted in the cutter hole. The coolant may flow through the coolant channels of the collet body and is guided to the heating point of the working cutter with the converged coolant channels.