A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting tool including a substrate and a coating film disposed on the substrate, wherein the cutting tool includes: a rake face; a flank face contiguous to the rake face; and a cutting edge region composed of a boundary part between the rake face and the flank face, wherein the coating film includes a TiSiCN layer, the TiSiCN layer has: a first TiSiCN layer positioned in the rake face; and a second TiSiCN layer positioned in the cutting edge region, the first TiSiCN layer has a composition of Ti.sub.(1-Xr)Si.sub.XrCN, the second TiSiCN layer has a composition of Ti.sub.(1-Xe)Si.sub.XeCN, and the Xr and the Xe each represent 0.010 or more and 0.100 or less, and satisfy a relationship of Xe-Xr≥0.003.

A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A machining apparatus for machining optical lenses has a horizontally aligned conveyor section for transporting containers containing at least one optical lens, the conveyor section extending between an entry and opposite exit side of a module. The machining apparatus has a container buffer store and a container transport device, the latter being designed to retrieve containers from the conveyor section and to store said containers in the container buffer store and to transport containers back onto the conveyor section. A workpiece handling station having at least one parking space is provided for one container. The container transport device transports containers from the container buffer store to at least one parking space. A handling device of workpiece handling station retrieves optical lenses from a container standing on a parking spaces and transfers said container to a machining station. Moreover, the invention relates to a manufacturing system having two such machining apparatuses.

Provided is a coated cutting tool having improved wear resistance and fracture resistance and a long tool life. The coated cutting tool includes a substrate, and a coating layer formed on a surface of the substrate. The coating layer has a laminated structure in which a first layer and a second layer are alternately laminated for one or more layers. The first layer is a compound layer having a composition represented by Ti(C.sub.xN.sub.1-x). The second layer is a compound layer having a composition represented by (Ti.sub.yAl.sub.1-y)N. The laminated structure includes first to third laminated structures in this order from a substrate side to a surface side of the coating layer. An average thickness per layer of each of the first layer and the second layer in the first to third laminated structures is in a specific range. An average thickness of the first to third laminated structures is in a specific range.

A rotary cutting tool includes a main body and a shank. The main body has a tip end. The shank is continuous with the main body on the side opposite to the tip end. The main body is provided with a first cutting edge having a positive twist angle, and a second cutting edge having a negative twist angle and separated from the first cutting edge. Each of the first cutting edge and the second cutting edge extends continuously from the tip end to the shank.

A cubic boron nitride sintered material comprises cubic boron nitride particles and a binding phase. The binding phase includes a first region and a second region. The first region accounts for 1.0 vol % or more in the binding phase. The first region includes a plurality of needle crystals. Each of the plurality of needle crystals includes a boride. Each of the plurality of needle crystals has an aspect ratio of 1.5 or more in a cross-section image of the cubic boron nitride sintered material.