The invention is directed to a drill system that better uses the power curve of modern machine tools. The drill system uses IC inserts to perform the major hole diameter cutting, and a central drilling system that cuts the remaining minor diameter portion of the hole, and is configured to see less cutting surface footage, due to its position from the rotating center of the tool. A connection between the drill head and a holder body secures the drill head in a manner to effectively absorb lateral drilling forces. The drill system allows for a large diameter deep hole that remains straight throughout to be drilled at higher speed and lighter feed rates thus offering a more productive tool that takes advantage of the power curves and lower thrust capabilities of modern machine tools.

A method of joining a plurality of parts to form a unitary body. At least two sintered parts are provided. At least one of the sintered parts has at least one internal cavity. Each of the parts is formed of a hard metal composition of material. The at least two sintered parts are assembled into the shape of a unitary body. Each of the at least two sintered parts has a joining surface and when each joining surface is brought into contact the surfaces form a bonding interface therebetween. The assembled parts are subjected to a vacuum or gas atmosphere, without the application of external pressure, and to a temperature sufficient to fuse the at least two sintered parts together at the bonding interface to form the unitary body.

A drilling head for a tubular shank having an inside diameter and threads may comprise an axial body comprising a duct exiting through a first end; threads adjacent the first end corresponding to the threads on the shank and aligning the duct with the shank inside diameter; a bore from an outer surface of the body to the duct; and two axially extending approximately parallel and offset surfaces adjacent a second end; and an insert affixed between the offset surfaces, the insert comprising: a first face at least partially contacting one offset surface and a second face at least partially contacting the other offset surface; one or more cutting edges adjacent the first face, the second face, or both; and a cutting lip adjacent one or more cutting edges.

Provided are a drill blank, a method for manufacturing a blank, a drill, and a method for manufacturing a drill which allow a step of brazing to be easy and allow the brazing to be precise. A drill includes a drill blank brazed thereto in an elongated columnar-shape and made of cemented carbide. In the drill blank, both d.sub.A and d.sub.B are equal to or smaller than 2 mm, d.sub.Ad.sub.B>d.sub.C, a ratio of the length to d.sub.A is equal to or larger than 3, and d.sub.B/d.sub.A=0.96 to 1 and d.sub.C/d.sub.A=0.9 to 0.995 in a longitudinal direction, where d.sub.A indicates the diameter of one end of both ends, d.sub.B indicates the diameter of the other end thereof, and d.sub.C indicates the minimum diameter of a central portion. Brazing of the drill blank is easy and precision in brazing is enhanced.

In a hard-film-coated drill having a cemented carbide drill body coated with a hard film, the drill body is provided with a smooth region at a boundary between a flank surface and a rake surface. The surface hardness of the hard film is within 2000 to 2500 HV in Vickers hardness. A radius r1 (m) of curvature of the first ridgeline L1 where the smooth region and the flank surface intersect is represented by r1=0.45D+a1 (10a125), where D is the diameter (mm) of the body. A radius r2 (m) of curvature the second ridgeline L2 where the flank surface and a margin intersect is represented by r2=0.65D+a2 (39a267). A thickness t1 (m) of the hard film is represented by t1=0.8ln(D)+a3 (0.7a33.0).

The present invention relates to a method for coating a substrate, preferably a drill, wherein at least one first HiPIMS layer is applied by means of a HiPIMS process. Preferably, at least one second layer is applied to the first HiPIMS layer by means of a coating process that does not contain a HiPIMS process.

A tapping tool is mountable on an adapter for tapping. The adapter includes a ring gear in which the tapping tool is mountable; and a gear holder in which the ring gear is disposed and which is mountable on a turret of a turret punch press so as to locate the disposed ring gear at a position corresponding to a punch mounting section formed in advance in the turret. The tapping tool includes a cylindrical body and a rotating body.