A cutting insert according to one embodiment includes: a rake face; a flank face continuous to the rake face; and a cutting edge constituted of a ridgeline between the rake face and the flank face. A coolant flow path is provided inside the cutting insert. One end portion of the coolant flow path opens in the flank face to form a coolant ejection hole. The flank face is provided with a coolant guide groove extending from the coolant ejection hole toward the cutting edge with a base end portion of the coolant guide groove being connected to the coolant ejection hole and with a front end portion of the coolant guide groove being disposed at a position close to the cutting edge relative to the base end portion.

[Problem] To protect a leading end part of a drill having a coolant hole which is adapted for drilling a thin diameter or very thin diameter hole in a workpiece.

[Solution] A coolant hole 33 is formed in a shank 3 and a shaft body 7 so as to extend through from a rear end surface 31 of the shank 3 to a leading end surface 15 of the shaft body 7 along an axis thereof. A leading end part of the coolant hole 33 is branched into a pair of discharge holes 35, at a position slightly toward a base end relative to the leading end surface 15 of the shaft body 13. The discharge holes 35 extend in the opposite directions, perpendicular to the coolant hole 33, respectively, and open at opposite side surfaces 37, 37 to define discharge ports 39, 39. A leading end opening 41 of the coolant hole 33 is closed by a bottom face 17 of the drill part 9.

In a method for operating a machine tool, a machine-specific flow resistance and a respective tool-specific flow resistance are ascertained for various tools. Tool-specific regulator parameters for regulating a pump of a coolant lubricant device are computed on the basis of the machine-specific flow resistance and the tool-specific flow resistance of the tool chucked in a tool spindle. Subsequently, the machine tool is operated using the tool-specific regulator parameters. In this way, a rapid and exact feed of coolant lubricant to the machining point of the respective chucked tool is enabled in a simple and flexible manner.

A control system for controlling oil-injection of a machine tool includes a sensor, a signal-processing device and a control device. The sensor senses movement of a machine component of the machine tool and outputs a sense signal to the signal-processing device. The signal-processing device derives analysis signals from the sense signal and sends the analysis signals to the control device. The control device determines whether to output an oiling signal to the machine tool to trigger an oiling device to oil the machine component according to an accumulated moving distance and a variation value that are calculated based on the analysis signals.

Tool holder for a tool for machining workpieces, with a tool holder body, which defines a longitudinal axis, on which a tool mount for securing a tool is formed and on which a tool holder interface for fixating the tool holder to a holder shaft is formed, wherein the tool holder interface comprises: a tool holder plane surface oriented transversely to the longitudinal axis, against which a holder shaft plane surface can abut to establish a defined relative position in longitudinal direction between the tool mount and the holder shaft, a tool holder cone section, which is polygonal in a cross-section and which can engage with a correspondingly polygonal holder shaft cone section to establish a defined relative position in tangential direction between the tool mount and the holder shaft, and a tool holder cylinder section which can act together with a corresponding holder shaft cylinder section.

A housing for an electric machine tool, in particular for a core drill, said housing in which a motor is accommodated, which has a motor shaft for driving a tool mount and to which cooling air is supplied through at least one air guide duct, which is delimited at one end by at least one air inlet and at the other end by at least one air outlet. A guide structure, providing air guidance for the cooling air and associated with a motor mount, in which the motor is at least partially accommodated, is disposed in the air guide duct downstream from the at least one air inlet.

According to one implementation, a drill includes: a body without a back taper and a cutting edge part. The body has a flow path of a cutting oil. The flow path is branched to first and second flow paths inside the body. The cutting edge part has a first supply port that supplies the cutting oil toward a workpiece. The first supply port is an outlet of the first flow path. The body has a second supply port that supplies the cutting oil to a clearance between the body and a bush for positioning the body. The second supply port is an outlet of the second flow path. The second flow path has a pressure loss by which the cutting oil is not scattered from the second supply port in a radial direction of the body but exuded from the second supply port.

A cutting tool includes a tool holding system having a clamping portion. The clamping portion includes an integrally formed one-piece inner coupling member that at least partially forms a clamping sleeve portion having a clamping bore for clampingly receiving a cutting insert. The clamping portion also includes an integrally formed one-piece outer coupling member that is circumferentially disposed about at least a portion of the inner coupling member. The tool holding system also has a mounting portion that is connected to one of the inner and outer coupling members. The inner and outer coupling members are captively and non-releasably engaged with each other via inter-engaged first and second engagement surfaces that are slidingly displaceable with respect to each other.

A parting lathe tool for machining metal is described. This has a clamping seat for receiving a cutting insert and an internal coolant supply system for supplying coolant to a cutting zone. In this case, the coolant supply system comprises at least three coolant outlets. The coolant outlets are fluidically connected to a coolant supply port via at least two separate coolant lines running within the parting lathe tool.

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.