A cutting insert is provided, comprising a top surface, a bottom surface, a plurality of side surfaces spanning therebetween, and a cutting edge formed at an intersection of the side surface and a forwardly-disposed portion of the top the surface. It further comprises a cooling cavity projecting into the insert, a top end thereof being disposed further forwardly than an open bottom end thereof. The cooling cavity defines at least one molding axis such that a solid element having the shape of the cooling cavity and completely inserted therein may be retracted intact therefrom along a linear path parallel to the molding axis. A circumscribing portion is formed on the side surfaces encircling the cutting insert. The circumscribing portion is formed parallel to the molding axis and has a non-zero height along its entire extent. The cutting insert does not extend beyond the circumscribing portion.

A drilling insert has a central portion with a central axis, and three circumferentially spaced tip portions. Each tip portion has a first axis and two diverging first cutting edges with radially outermost cutting points defining a first circle lying on a tip plane perpendicular to the first axis and having a first cutting diameter. In a view along one of the first axes, a second circle having a second diameter circumscribes the drilling insert, and the first cutting diameter is at least sixty percent of the second diameter. A cutting tool rotatable about a tool axis with a tool cutting diameter includes the drilling insert, and a second cutting insert having a second cutting edge. One of the tip portions is operative having its first axis coaxial to the tool axis, and the second cutting edge extends radially outward of the first cutting diameter.

A polygonal cutting blade having a circular arc-shaped groove in a hole includes a blade body composed of an upper surface, a lower surface and a plurality of main side surfaces connecting the upper surface and the lower surface. The blade body has a central hole penetrating through the upper surface and the lower surface, and is centrally symmetrical about a central axis of the central hole. At least one set of positioning side surface comprised of adjacent two of the main side surfaces is provided. An inner surface of the central hole has at least one circular arc-shaped groove fitting with a fastening screw for fixing the cutting blade. The circular arc-shaped groove directly faces toward an intersection of the two main side surfaces of the set of positioning side surface. A groove central axis of the circular arc-shaped groove has an offset distance from the central axis.

A cutting insert for drilling includes an upper surface, a lower surface formed on an opposite side of the upper surface, a side surface connecting the upper surface and the lower surface; a cutting edge formed at an intersection of the upper surface and the side surface, and a ridge portion formed to protrude upward from the upper surface to facilitate chip control. The ridge portion includes a ridge body spaced apart from the cutting edge and disposed at a central portion of the cutting insert for drilling; and a ridge extension portion extending from a vicinity of a corner of the ridge body in a direction parallel to the cutting edge.

This invention relates to simple, compact rotary seals that contract to maintain a seal as the sealing elements may wear over time. Embodiments of this invention allow simple elastic rings, such as an O-ring, to be used as the sealing element.

A method for cutting an inner circumferential surface of a rotating hollow cylindrical workpiece includes: holding the workpiece with a chucking device such that a side surface of the workpiece on a first side in an axial direction of the workpiece is in contact with a contact surface of the chucking device; setting an intersection angle between a rotational center line of the workpiece and an imaginary straight line to an angle smaller than 45 degrees, the straight line being parallel to an axis line of a button tip and intersecting with the rotational center line; and setting a feed direction of the button tip to the inner circumferential surface to a direction from a second side in the axial direction of the workpiece toward the first side in the axial direction thereof, and cutting the inner circumferential surface by use of the button tip rotating about the axis line.

A cutting insert is provided, comprising a top surface, a bottom surface, a plurality of side surfaces spanning therebetween, and a cutting edge formed at an intersection of the side surface and a forwardly-disposed portion of the top the surface. It further comprises a cooling cavity projecting into the insert, a top end thereof being disposed further forwardly than an open bottom end thereof. The cooling cavity defines at least one molding axis such that a solid element having the shape of the cooling cavity and completely inserted therein may be retracted intact therefrom along a linear path parallel to the molding axis. A circumscribing portion is formed on the side surfaces encircling the cutting insert. The circumscribing portion is formed parallel to the molding axis and has a non-zero height along its entire extent. The cutting insert does not extend beyond the circumscribing portion.

A cutting edge tip of a cubic boron nitride sintered body has improved joint strength to a substrate of a cemented carbide. A cutting edge tip of a cubic boron nitride sintered body has improved crater wear resistance. A tool 10 of the present invention includes a substrate 12 of a cemented carbide and a cutting edge tip 14 of a cubic boron nitride sintered body joined to the substrate 12. The cutting edge tip 14 has a thickness covering an upper surface 12a to a lower surface 12b of the substrate 12. The cubic boron nitride sintered body contains 50 volume % or more and 95 volume % or less of cubic boron nitride and 5 volume % or more and 50 volume % or less of a binder phase. The cubic boron nitride has an average grain size of 1.0 m or more and 6.0 m or less.

This invention relates to cutting tools used to machine materials to produce new surfaces and chips of removed material. Embodiments of this invention allow round rotating cutting inserts to be used in a more economical way, with improved accuracy, with improved sealing, and with greater ease of use. The rotary support device and cutting inserts may be used in either radial or tangential mounting types of cutters. It also provides a built-in, fully sealed means of fine adjustment of the cutting insert that is useful in some applications.

The flow of heat energy from the cutting edge rim of a self-propelled round annular rotary cutting element (insert) to axial-load and radial-load bearings in a cartridge which rotatably supports the insert on a machine tool body is reduced by defining heat flow paths from the insert rim to cartridge components which engages the bearings to have low thermal conductance relative to heat flow paths from the insert rim to other parts of the cartridge. Control over heat flow path thermal conductance is obtained by selection of materials used between the insert rim and the mentioned cartridge components, by reductions in the cross-sectional areas of the critical heat flow paths, and by combinations of those two techniques. Protection of the bearings from heat enables the insert and the cartridge to be reduced in size. Improved mountings of insert-supportive cartridges to tool bodies are disclosed. The insert and the cartridge preferably are shaped to enable the insert to be positioned on a tool body so that the insert's rake face can have a positive rake orientation relative to a workpiece. Arrangements for controlling cuttings chip formation and for handling cuttings chips also are disclosed.