Provided is a cutter apparatus for machining a difficult-to-machine material, the cutter apparatus including: a cutting tool body which has a fastening portion formed at a center thereof; one or more cutters which are installed on the cutting tool body, and have superhard insert tips fixed to end portions thereof, respectively; and an angle adjusting unit which is installed in an internal space of the cutters, and adjusts angles of the cutters by spreading or retracting the cutters, so that angles of the cutters may be easily adjusted in accordance with a condition for cutting a difficult-to-machine material, in order to prevent damage to the superhard insert tips when machining a difficult-to-machine material having high hardness and high toughness.

The disclosure concerns a system for hole drilling in an object (400) comprising a core drilling machine (100), a core drill bit (200) and a reaction bar (300) arranged for transmitting rotating reaction forces from the core drilling machine (100) to the object (400), where the core drill bit (200) is connected to the core drilling machine (100) and the core drilling machine (100) is equipped with a power source (108) in order to apply a rotating force to the core drill bit (200), and where the core drill bit (200) has an axially extending tubular shaft (202) with an inner envelop surface (203) defining an inner periphery (204) of the core drill bit (200), wherein the reaction bar (300) is non-rotatably connected to the core drilling machine (100) and arranged inside the inner periphery (204) of the axially extending tubular shaft (202) of the core drill bit (200). The disclosure further concerns a core drill bit (200) and a core drilling machine (100) for hole drilling in an object (400) and a method for hole drilling in an object (400) with a core drilling machine (100), a core drill bit (200) and a reaction bar (300) arranged for transmitting rotating reaction forces from the core drilling machine (100) to the object (400).

A deburring tool has a hollow top portion having an interior conical surface and an exterior surface. The exterior surface of the deburring tool is preferably conical. The top portion has a plurality of flutes formed therein and extending between the interior and exterior surfaces. Each of the flutes has a cutting edge formed at the interior conical surface. In operation, rotation of the deburring tool about a longitudinal axis removes burrs projecting from bar stock contacting the interior conical surface. A method of deburring bar stock comprises: (a) rotating the deburring tool about a longitudinal axis, and (b) contacting the bar stock to the deburring tool interior conical surface.

A tool for machining an outer circumferential surface of a workpiece, with an interface adapted for fastening the tool to a counter interface, and a base body which is cylindrical at least in sections. The base body has a circumferential wall encompassing a mounting space and is configured to be open at the frontal side in such a way that the workpiece can be at least partially accommodated in the mounting space. At least one cutting edge engaging in the mounting space is arranged on the base body for the machining of the outer circumferential surface of the workpiece. The circumferential wall has at least one chip passing recess which is arranged relative to the at least one cutting edge in such a way that chips removed by the at least one cutting edge during the machining of the workpiece can exit through the at least one chip passing recess from the mounting space into an outer surrounding area of the base body.

A self-locking head-replaceable carbide drill, comprising a cutter head disposed at the upper end of a cutter shank. A cylinder is disposed at the lower part of the cutter head, a vertical cylinder holding slot or cylinder handle holding hole is disposed at the upper end of the cutter bar, at least two cutter head notches are disposed on the drilling body of the cutter head, and each cutter head notch is formed by intersecting a first and a second cutter head contact face. At least two upward protrusions disposed on the wall of the upper end of the cutter bar and have the same number as the cutter head notches. When assembling the cutter head and the cutter shank, the cutter head ridge edges and the inner surfaces of the protrusions are in non-contact fit, interference fit and non-interference fit in sequence.

A hard coating, which is to disposed to cover a surface of a tool substrate, has a total thickness of 0.5-20 m and includes an A layer and nanolayer-alternated layer that are alternately laminated by physical vapor deposition. The nanolayer-alternated layer includes a B layer and C layer that are alternately laminated. The A layer has a thickness of 50-1000 nm and is AlCr(SiC) nitride that is represented by a composition formula of [Al.sub.1-W-XCr.sub.W(SiC).sub.X]N wherein an atomic ratio W is 0.20-0.80 and an atomic ratio X is 0.01-0.20. The B layer has a thickness of 1-100 nm and is TiAl nitride that is represented by a composition formula of [Ti.sub.1-YAl.sub.Y]N wherein an atomic ratio Y is 0.30-0.85. The C layer has a thickness of 1-100 nm and is Ti(SiC) nitride represented by a composition formula of [Ti.sub.1-Z(SiC).sub.Z]N wherein an atomic ratio Z is 0.05-0.45. The nanolayer-alternated layer has a thickness of 50-1000 nm.

A cutting insert is used in a cutting edge replaceable rotary cutting tool. The cutting insert includes a first cutting edge formed on an intersecting ridge portion between a first end surface of two opposite end surfaces and a circumferential side surface, and a first depressed portion formed along a part of the first cutting edge. The first depressed portion is provided to form a larger rake angle at the first cutting edge than that at a part not having the first depressed portion of the first cutting edge.

A body may be provided having first and second ends having threaded outer surfaces. A bore may extend between the first and second ends. A tool may be provided having a first outer mold-line surface, a second opposing surface, and a hole extending between the first and second opposing surfaces. The first end may be threadedly attached and sealed, at the second opposing surface, to an inner surface of the hole. A cap may be threadedly attached and sealed to the second end of the body. A composite may be consolidated against the first outer mold-line surface of the tool. The cap may be unthreadedly removed from the second end. A drill bit may be inserted into the bore, through the tool hole, and against the composite to drill a composite hole.

A deburring tool has a hollow top portion having an interior conical surface and an exterior surface. The exterior surface of the deburring tool is preferably conical. The top portion has a plurality of flutes formed therein and extending between the interior and exterior surfaces. Each of the flutes has a cutting edge formed at the interior conical surface. In operation, rotation of the deburring tool about a longitudinal axis removes burrs projecting from bar stock contacting the interior conical surface. A method of deburring bar stock comprises: (a) rotating the deburring tool about a longitudinal axis, and (b) contacting the bar stock to the deburring tool interior conical surface.

A drill configured for drilling ductile materials includes a drill margin with a margin extremity adjacent to a relief surface. The drill includes a drill body and a drill head secured to the drill body via rotational coupling of the drill head on the drill body.