A single-sided four-way indexable cutting insert includes a positive basic shape, a rake surface, a peripheral surface including four side abutment surfaces, a base bearing surface and a screw hole connecting the rake and base bearing surfaces. The insert has an imaginary square frustum which defines a square base containing the cutting insert's base bearing surface, and further defines four isosceles trapezoid side surfaces respectively containing the cutting insert's four side abutment surfaces. A material volume V.sub.F of the cutting insert and a void volume V.sub.S of the insert fulfill the condition V.sub.S/V.sub.F0.25.

A tool body having an insert seat and a cutting tool which allow a cutting insert to be stably held are provided. A tool body according to the present invention is a tool body having an insert seat for mounting a cutting insert on the tool body, wherein the insert seat has a base surface and a side wall surface which extends so as to intersect with the base surface. The base surface has a contact surface and a contact projected part which come into contact with the cutting insert. A contact part of the contact surface is comprised of a surface, and a contact part of the contact projected part has a linear shape or a point shape.

A rotary cutting tool is provided which, although it has a simple configuration, allows the arrangement of each cutting edge to be easily adjusted. A first cartridge mounting seat has an upper wall surface opposing an outer side surface of a cartridge and further has a first recessed part into which a protrusion is inserted and which comes into contact, at a bottom thereof, with a leading end of the protrusion. A second cartridge mounting seat has an upper wall surface opposing an outer side surface of a cartridge and further has a second recessed part into which a protrusion is inserted and which comes into contact, at a bottom thereof, with a leading end of the protrusion. A depth of the second recessed part is greater than a depth of the first recessed part. An amount of protrusion P of the protrusion is equal to or greater than the depth of the second recessed part.

In an embodiment, a cutting tool includes a holder that is a columnar body and includes a pocket in which an insert disposed. The pocket includes a first surface in contact with the insert, a second surface, and a projecting portion. The second surface is disposed further forward in a rotational direction of a rotational axis than the first surface, and disposed on a radial inner side of the holder. The projecting portion is disposed closer to a radial outer circumferential side of the holder than the first surface and projects forward in the rotational direction of the rotational axis. The second surface is inclined and comes closer to an outer circumference of the holder as going forward in the rotational direction of the rotational axis, in a front view of a first end.

A hardware fastener with a movable threaded element suspended within a cavity formed in a body. The movable threaded element has an internal surface with threads for cooperating with a threaded fastener. The movable threaded element is suspended in the cavity by the one or more spring-like members such that an area, A, of reduced stiffness is created in the cavity proximate the movable threaded element, thereby allowing the movable threaded element to move a predetermined distance within the cavity when torque is applied to the threaded fastener. The one or more spring-like members store elastic potential energy to prevent the loss of pretension of the threaded fastener that can be caused by heat or vibration. The invention also eliminates the need for a torque wrench when tightening the threaded fastener to a specified torque value.

An adzer bit includes a support member that defines a through hole that is configured to receive a fastener. The support member includes a cutting segment cap portion and a base portion. The support member also defines an annular slot that is axially disposed between the cutting segment cap portion and the base portion. A plurality of cutting segments are received and secured in the annular slot. The material of the plurality of cutting segments is harder than the material of the support member.

A cutting insert comprises: a first end surface and a second end surface which are opposed to each other; a peripheral side surface which extends so as to connect the first end surface and the second end surface; a first cutting edge which is arranged in an intersecting edge between the first end surface and the peripheral side surface; and a second cutting edge which is arranged in an intersecting edge between the second end surface and the peripheral side surface. The peripheral side surface includes a first flank which is connected to the first cutting edge and an intermediate peripheral side surface portion which is arranged closer to the second end surface than the first flank. The first flank extends in a direction perpendicular to the first end surface. The intermediate peripheral side surface portion protrudes outward from the first flank.

A single-sided four-way indexable cutting insert includes a positive basic shape, a rake surface, a peripheral surface including four side abutment surfaces, a base bearing surface and a screw hole connecting the rake and base bearing surfaces. The insert has an imaginary square frustum which defines a square base containing the cutting insert's base bearing surface, and further defines four isosceles trapezoid side surfaces respectively containing the cutting insert's four side abutment surfaces. A material volume V.sub.F of the cutting insert and a void volume V.sub.S of the insert fulfill the condition V.sub.S/V.sub.F0.25.

An indexable cutting insert has opposing upper and lower end surfaces, and a peripheral surface including three side surfaces circumferentially alternating with three corner surfaces. The three side surfaces define an imaginary triangle and an imaginary hexagon. Each corner surface intersects the upper end surface to form an upper corner peripheral edge having a primary cutting edge. In a top view, each triangle side traverses two upper corner peripheral edges, imaginary lines tangential to the end points of each primary cutting edge are either collinear or form an obtuse angle greater than 175 degrees, each primary cutting edge has a primary length greater than half the hexagon side length, and at least one triangle side traverses each primary cutting edge. The insert is removably secured in a rotary cutting tool such that one of the upper corner peripheral edges contains an axially forwardmost point of the insert's upper peripheral edge.

The purpose of the present invention is to provide a cutting insert capable of reducing cutting load and enhancing squareness. A cutting insert, according to one embodiment of the present invention, comprises: first and second end surfaces which face opposite directions to each other and have four corners wherein two ascending corners are placed in one diagonal position, and two descending corners lower than the height of the ascending corners are placed in the remaining diagonal position; first and second main side surfaces which are placed between the first and second end surfaces, face in opposite directions to each other, and have a throughhole connecting the first and second main side surfaces to each other; and first and second auxiliary side surfaces placed between the first and second end surfaces and between the first and second main side surfaces, wherein, when seen from the first or second end surface, each of the first and second main side surfaces comprises: a central main clearance surface placed on a central portion thereof; a first peripheral main clearance surface which is placed between the central main clearance surface and the ascending corners, and which forms an obtuse angle with respect to the central main clearance surface such that the central main clearance surface may protrude; and a second peripheral main clearance surface which is placed between the central main clearance surface and the descending corners, and forms an obtuse angle with respect to the central main clearance surface such that the central main clearance surface may protrude.