A rotary cutting tool including a cutter member having an axial forward end and an axial rearward end. A cutting region is at the axial forward end of the cutter member, and a male threaded portion is adjacent the axial rearward end of the cutter member. A shank member has an axial forward end and a shank bore opening at the axial forward end. The shank bore has an axial shank bore length. The shank bore contains a female threaded portion and an axial rearward shank bore portion axially rearward of the female threaded portion. The axial rearward shank bore portion has a terminal end. When the male threaded portion of the cutter member fully engages the female threaded portion of the shank member, the axial rearward end of the cutter member being spaced a first distance axially forward of the terminal end of the axial rearward shank bore portion.

A rotary cutting tool includes a cutter of generally cylindrical shape disposed about a central longitudinal axis. The cutter has a first end having an active fluted portion and an opposite second end, the second end having a male threaded portion disposed thereabout. The cutting tool further includes a shank of generally cylindrical shape disposed about the central longitudinal axis, the shank having a recessed female threaded portion formed in a first end. The male threaded portion includes a number of threads disposed at a first pitch and the female threaded portion includes a number of threads disposed at a second pitch different than the first pitch. The cutter and the shank are selectively coupled via threaded engagement of the male threaded portion and the female threaded portion.

A replaceable head cutting tool increases the strength of engagement between a tool body and a coupling member without causing damage. A cylindrical mounting unit of the coupling member which is made of a metal having hardness lower than the hardness of the tool body, is inserted into a mounting hole having a concave portion formed on the inner surface of the tool body. The mounting unit is plastically deformed so as to increase in diameter, and the outer peripheral surface of the mounting unit contacts the inner peripheral surface of the mounting hole and is engaged with the concave portion which includes a first wall surface that is inclined toward the outer peripheral side as it moves in an insertion direction of the mounting unit, and a second wall surface that is inclined toward the inner peripheral side as it moves in the insertion direction.

An end mill, preferably made of solid carbide, with a fastening section and a cutting area, in which the cutting area is formed by a core and three, four or five cutting edges arranged around core and running helically around the axis of rotation of the end mill, each one of which has a peripheral main cutting edge and a secondary cutting edge on the face of cutting area. In order to create an end mill simple to manufacture and optimized for drilling, at least one cutting edge on the face of cutting area has a single, flat or continuously curved front surface, which delimits the cutting edge in the longitudinal direction of the mill on face.

An end mill, preferably made of solid carbide, with a fastening section and a cutting area, in which the cutting area is formed by a core and three or four cutting edges running helically around the axis of rotation of the end mill and arranged around core; each of which has a peripheral main cutting edge and a secondary cutting edge on a face of the cutting area. On the face of the cutting area at least one point thinning of core is provided between two adjacent cutting edges. In order to create end mills that are simple to manufacture and optimized for drilling, the point thinning has an angle of 30 to 40 relative to the axis of rotation of the end mill.

A replaceable cutting head includes a forward cutting portion and a rearward mounting portion. The mounting portion includes a male coupling member that protrudes rearwardly from a head base surface. The male coupling member includes forward and rearward bearing portions and an external thread located therebetween. The forward and rearward bearing portions include respective conically shaped forward and rearward head abutment surface. The forward and rearward head abutment surfaces have the same cone angle. When a cutting tool, including said cutting head and a tool holder having a female coupling member, is in a locked position, the external thread is threadingly engaged in the female coupling member and the forward and rearward head abutment surfaces conically abut corresponding conical shaped surfaces in the female coupling member.

A rotatable cutting tool, which extends along a tool axis defining an axial direction, includes a cutting formation in a first axial longitudinal end region, which is configured for material ablation on a workpiece, and includes a screw-connection formation in a second axial longitudinal end region opposing the first, which is configured for screw connection with a coupling unit. The cutting tool includes key-contact surface formations diametrically opposing each other with respect to the tool axis, which are configured for torque-transmitting abutting engagement with key surfaces of a key. Each of the key-contact-surface formations includes at least two key-contact surface regions provided with spacing from each other in the circumferential direction about the tool axis, which key-contact surface regions are inclined away from each other such that they form a vertex projecting away from the tool axis.

Provided is a replaceable machining head wherein: fractures on the tool attaching portion do not occur; the production cost is minimized; the tool life of the working tool will be lengthened; and the head body is free from a risk of falling off during replacement. In the replaceable machining head, a cutting edge section is formed on the front side of a head body; a tool attaching portion to which a working tool is to be attached, is formed on the rear end side of the cutting edge section; tool attaching faces are formed in the tool attaching portion; the surface of the head body 1 is coated with a coating film; and the number of droplets or macro particles having convex shapes with a size of 0.3 m to 5.0 m, is 200 or less, per area of 40 m60 m on the surface of the coating film over the tool attaching faces.

An assembly-type cutter includes a shank and a cutter head. The shank has a hole at one end. The hole has a receiving portion, which includes an internal thread and can be treated thermally for increased rigidity. The cutter head has a cutting portion and a connecting portion at opposite ends respectively. The connecting portion includes a threaded member and can also be treated thermally for increased rigidity. The cutter head and the shank are threadedly connectable via the connecting portion and the receiving portion. The threaded member includes a body portion, whose diameter is defined as a root diameter, and an external thread on the body portion. The body portion is slightly tapered such that a locus of the root diameter is inclined.

A cutter assembly is configured to interchange a cutter bit and has a plurality of retaining features to secure the cutter bit to ensure positive retention and alignment along a rotational axis. The cutter bit is retained within a slot of the retainer component and the retainer component is coupled to a chuck component. The retainer component may be detachably attachable to the chuck component by external threads that are configured to thread into the internal threads of the chuck component. The cutter bit may be retained in the slot by a threaded retainer that extends through one side of the retainer component, through a cutter aperture in the cutter bit, through the slot and into a threaded retainer aperture in the opposing side of the retainer component.