Abstract: A cutter fastening assembly has a tool block, a fastening bolt, a fastening unit, a collet, and a cutter holder. The fastening bolt, the fastening unit, and the collet are mounted inside the tool block. The cutter holder has an assembling seat and a threaded hole. The assembling seat is integrally formed on the cutter holder and has a flange portion. The threaded hole is axially defined inside the flange portion and is screwed with the fastening bolt to keep the cutter holder connecting with the tool block.

Abstract: A cutter holder has a body, a fastening bolt, and a vibration absorbing structure. The body has a specific weight. The fastening bolt is mounted inside the body. The vibration absorbing structure is mounted inside the body and has a sleeve, an elastic unit, a spacer, and a set nut. The sleeve is mounted around the fastening bolt and has a specific weight. The specific weight of the sleeve is larger than the specific weight of the body. The elastic unit is mounted around the fastening bolt and has two opposite ends. One of the ends of the elastic unit abuts against the sleeve. The spacer is mounted around the fastening bolt and abuts against the other end of the elastic unit. The set nut is screwed with the fastening bolt and abuts against the spacer.

Abstract: An easily detachable collet has two opposite ends, a conjoint portion, a fastening cap abutting portion, an annular groove, a through hole, and multiple slits. The conjoint portion is arranged at one of the two opposite ends of the collet. The fastening cap abutting portion is annularly formed at the other end of the collet. The fastening cap abutting portion has a convex outline in cross section. The annular groove is formed between the conjoint portion and the fastening cap abutting portion. The through hole is axially defined through the collet. The multiple slits are radially defined in the collet and communicate with the through hole. Each slit extends to one of the two opposite ends of the collet. The fastening cap abutting portion with a convex outline in cross section enables the collet to be smoothly and easily detached from a fastening cap.

Abstract: A cutter holder has a body, a fastening bolt, and a vibration absorbing structure. The body has a specific weight. The fastening bolt is mounted inside the body. The vibration absorbing structure is mounted inside the body and has a sleeve, an elastic unit, a spacer, and a set nut. The sleeve is mounted around the fastening bolt and has a specific weight. The specific weight of the sleeve is larger than the specific weight of the body. The elastic unit is mounted around the fastening bolt and has two opposite ends. One of the ends of the elastic unit abuts against the sleeve. The spacer is mounted around the fastening bolt and abuts against the other end of the elastic unit. The set nut is screwed with the fastening bolt and abuts against the spacer.

Abstract: A cutter fastening assembly has a tool block, a fastening bolt, a fastening unit, a collet, and a cutter holder. The fastening bolt, the fastening unit, and the collet are mounted inside the tool block. The cutter holder has an assembling seat and a threaded hole. The assembling seat is integrally formed on the cutter holder and has a flange portion. The threaded hole is axially defined inside the flange portion and is screwed with the fastening bolt to keep the cutter holder connecting with the tool block.

Abstract: A cutter holder has a body, a fastening bolt, and a vibration absorbing structure. The body has a specific weight. The fastening bolt is mounted inside the body. The vibration absorbing structure is mounted inside the body and has a sleeve, an elastic unit, a spacer, and a set nut. The sleeve is mounted around the fastening bolt and has a specific weight. The specific weight of the sleeve is larger than the specific weight of the body. The elastic unit is mounted around the fastening bolt and has two opposite ends. One of the ends of the elastic unit abuts against the sleeve. The spacer is mounted around the fastening bolt and abuts against the other end of the elastic unit. The set nut is screwed with the fastening bolt and abuts against the spacer.

Abstract: A boring head has a connecting rod, an extending bracket and a cutter mount. The extending bracket is detachably connected with the connecting rod. The cutter mount is securely connected with a front end of the extending bracket. Because the extending bracket is detachably connected with the connecting rod, the extending bracket is replaceable, and the length of the extending bracket can be changed to make a bore with a desired diameter.

Abstract: A sealing device for a collet chuck has a tensioning nut, a sealing washer, a main sealing ring and a pressure space. The sealing washer is mounted in the tensioning nut and has a main ring groove, an abutting surface, a liquid-inlet surface, and a liquid inlet. The liquid inlet is formed between an imaginary surface extending from the abutting surface and the liquid-inlet surface. The main sealing ring is mounted and positioned in the main ring groove. The main sealing ring protrudes out of and abuts the main ring groove. The pressure space is formed between a rear side of the main sealing ring and the main ring groove. Therefore, a coolant poured into the sealing device can pressure the main sealing ring to deform the main sealing ring, such that the main sealing ring can tightly abut a tool shank.

Abstract: A boring head has a connecting rod, an extending bracket, a cutter mount, and a cutter. The extending bracket is securely connected with the connecting rod. The cutter mount is detachably connected with a front end of the extending bracket. As the cutter mount is detachably connected with the extending bracket, the cutter mount is replaceable, and the length of the cutter mount can be adjusted to produce a bore with a desired diameter.

Abstract: A sealing device for a collet chuck has a tensioning nut, a sealing washer, a main sealing ring and a pressure space. The sealing washer is mounted in the tensioning nut and has a main ring groove, an abutting surface, a liquid-inlet surface, and a liquid inlet. The liquid inlet is formed between an imaginary surface extending from the abutting surface and the liquid-inlet surface. The main sealing ring is mounted and positioned in the main ring groove. The main sealing ring protrudes out of and abuts the main ring groove. The pressure space is formed between a rear side of the main sealing ring and the main ring groove. Therefore, a coolant poured into the sealing device can pressure the main sealing ring to deform the main sealing ring, such that the main sealing ring can tightly abut a tool shank.

Abstract: A boring head has a connecting rod, an extending bracket and a cutter mount. The extending bracket is detachably connected with the connecting rod. The cutter mount is securely connected with a front end of the extending bracket. Because the extending bracket is detachably connected with the connecting rod, the extending bracket is replaceable, and the length of the extending bracket can be changed to make a bore with a desired diameter.

Abstract: A sleeve for heating a toolholder is magnetizable and has a sleeved space, at least one slit, and an abutting surface. The sleeved space is formed along an axial direction of the sleeve. The at least one slit is formed on the sleeve. The abutting surface is formed inside the sleeve. The sleeve is mounted around a toolholder by the sleeved space, and the abutting surface abuts the cutting tool. The sleeve can be heated by electromagnetic force, especially for steel material containing high chromium, and heats the toolholder by heat conduction. As a result, the toolholder can be heated easily by the sleeve, and can be mounted tightly and firmly around a cutting tool.

Abstract: A cutter-tooling assembly has a tool holder and a cutter. The tool holder has an inserted section and a through hole axially formed through the inserted section. The through hole has a fixing segment. The fixing segment has an inner surface and multiple recesses formed around the inner surface of the fixing segment at intervals. The cutter is inserted into the through hole of the tool holder and has a fixing end. The fixing end has an outer surface and multiple corners formed on the outer surface of the fixing end and abutting the recesses. Because the fixing segment has the multiple recesses which the corners of the cutter abut, the combination of the recesses and the corners can prevent a relative rotation between the tool holder and the cutter and make the cutter securely connected with the tool holder.

Abstract: A cutter holder has a holder body and a sleeve. The holder body has a first end, a middle, an insert part and a mounting part. The insert part is formed on the first end. The mounting part is formed on the middle of the holder body and has an outer thread formed around the mounting part. The sleeve is mounted around the mounting part and has an inner thread, multiple screw holes and multiple setscrews. The inner thread is formed on an inner surface of the sleeve, is screwed with the outer thread of the mounting part. The screw holes are separately defined through the sleeve. The setscrews are mounted in the screw holes and abut the mounting part.

Abstract: An adjusting magnetism shelter of a cutter holder has a stationary collar, a sliding assembly and a cap. The stationary collar has a disk and multiple sliding recesses. A first hole is defined in the disk. The sliding recesses are defined in the disk. The sliding assembly has multiple sliding bars. Each sliding bar is mounted in a sliding recess and has a magnetism bar and a moving shaft. The magnetism bar has a reflection surface. The moving shaft protrudes from each sliding bar. The cap covers the stationary collar and has a top board. The top board has multiple arc grooves. Each arc groove has an inner end and an outer end. The inner end of the arc groove is near the first hole. The outer end of the arc groove is far away from the first hole and is inserted into one of the moving shafts.

Abstract: A cutter-tooling assembly has a tool holder, a positioning chunk, a cutter and a collet. The tool holder has a through hole axially formed through the tool holder. The positioning chunk is screwed in the through hole and has a cavity. The cavity has multiple corners formed around an inner surface of the cavity. The cutter is inserted into the through hole and has multiple edges abutting the corners. Because the cross sectional shape of the cavity is multilateral and has multiple corners which the edges abut, the combination of the corners and the edges can prevent a relative rotation between the tool holder and the cutter and make the cutter securely connected with the tool holder.

Abstract: An easily-positioned cutter chuck has a through hole formed through the cutter chuck. The through hole has an end and a reamed part formed at the end of the through hole and reaming outwardly at two gradients. Because the reamed part enlarges an area ratio of an opening of the through hole to an end surface of the cutter chuck, a protrusion of a positioning apparatus can be easily aimed at and inserted into the reamed part. Because the cutter chuck can be held and positioned steadily by the positioning apparatus, tolerances of the cutter chuck can be well controlled when the outer surface of the cutter chuck is processed for polishing.

Abstract: An inner cooling cutter chuck has a through hole, multiple first cooling passageways and a threaded section. The through hole of the inner cooling cutter chuck is axially formed through the inner cooling cutter chuck and has an inner surface. The first cooling passageways are formed in the inner cooling cutter chuck and communicate with the through hole of the inner cooling cutter chuck. The threaded section is formed around the inner surface of the through hole of the inner cooling cutter chuck. The first cooling passageways enable the inner cooling cutter chuck to contain more cooling liquid. Inner surfaces of the first cooling passageways can increase heat-dissipating areas inside the inner cooling cutter chuck. Accordingly, the first cooling passageways can enhance the cooling effect.

Abstract: A cutter-tooling assembly has a tool holder and a cutter. The tool holder has an inserted section and a through hole axially formed through the inserted section. The through hole has a fixing segment. The fixing segment has an inner surface and multiple recesses formed around the inner surface of the fixing segment at intervals. The cutter is inserted into the through hole of the tool holder and has a fixing end. The fixing end has an outer surface and multiple corners formed on the outer surface of the fixing end and abutting the recesses. Because the fixing segment has the multiple recesses which the corners of the cutter abut, the combination of the recesses and the corners can prevent a relative rotation between the tool holder and the cutter and make the cutter securely connected with the tool holder.

Abstract: A boring bit has a head, a blade assembly and a blade. The head has a mounting recess and two holding protrusions. The mounting recess is formed in the head and has a restricting surface and a threaded hole. The holding protrusions are formed on the restricting surface and each has two oblique restricting faces. The blade assembly is attached to the head and has a mounting base. The mounting base is mounted in the mounting recess and has an inner surface, a through hole and a guiding channel. The inner surface abuts with the restricting surface. The through hole is formed through the mounting base and aligns with the threaded hole. The guiding channel is formed in the mounting base, is mounted around the holding protrusions and has two abutting surfaces abutting the oblique restricting faces of the holding protrusions. The blade is detachably mounted on the blade assembly.