A drill press has a main housing, a drill unit supported by the main housing for relative movement therewith, and a base coupled to the main housing, the base includes a magnet assembly to create a magnetic field for magnetically latching the base to a workpiece. The magnet assembly is rotatably attached to the base and includes a shaft and at least one permanent magnet disposed on the shaft. The shaft is rotatable between a first position where the base would not magnetically engage the workpiece and a second position where the base would engage the workpiece. An auxiliary handle is pivotably attached to the main housing and movable from a first handle position preventing removal of a power tool battery pack from the main housing and a second handle position allowing removal of the power tool battery pack from the main housing.

A drill press has a main housing, a drill unit supported by the main housing for relative movement therewith, and a base coupled to the main housing, the base includes a magnet assembly to create a magnetic field for magnetically latching the base to a workpiece. The magnet assembly is rotatably attached to the base and includes a shaft and at least one permanent magnet disposed on the shaft. The shaft is rotatable between a first position where the base would not magnetically engage the workpiece and a second position where the base would engage the workpiece. An auxiliary handle is pivotably attached to the main housing and movable from a first handle position preventing removal of a power tool battery pack from the main housing and a second handle position allowing removal of the power tool battery pack from the main housing.

A machining tool forms a first relief surface, a valve seat surface, and a second relief surface by cutting the inner periphery of a valve seat blank having an opening. The machining tool is provided with: a tool body rotationally driven about an axis; a plurality of cutting tools rotating with the tool body; a cartridge mounted to the tool body so as to be capable of moving forward and backward along the axis; and a cam in contact with the base end surface of the cartridge and moving the cartridge forward and backward. At least one of the plurality of cutting tools is mounted to the cartridge.

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 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 headstock structure of computer numerical control milling and boring machine tool comprising a spindle, a conducting slip ring, a rotating plate, a mobile unit, two balancing units, a driving unit, and a cutter locking unit; the conducting slip ring being sleeved on a top end of the spindle; the rotating plate being rotated in horizontal direction under the drive of the spindle; the mobile being rotated in horizontal direction together with the rotating plate; the two balancing units being located on the rotating plate; the driving unit being configured to drive the mobile unit to perform horizontal radial movement; the cutter locking unit being configured to lock the cutter, so that the headstock structure can rotate and move up and down, and can perform horizontal radial motion.

A headstock structure of computer numerical control milling and boring machine tool comprising a spindle, a conducting slip ring, a rotating plate, a mobile unit, two balancing units, a driving unit, and a cutter locking unit; the conducting slip ring being sleeved on a top end of the spindle; the rotating plate being rotated in horizontal direction under the drive of the spindle; the mobile being rotated in horizontal direction together with the rotating plate; the two balancing units being located on the rotating plate; the driving unit being configured to drive the mobile unit to perform horizontal radial movement; the cutter locking unit being configured to lock the cutter, so that the headstock structure can rotate and move up and down, and can perform horizontal radial motion.

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 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 vibration damping toolholder for a metal cutting tool, the toolholder including a holder body provided with an internal cavity, which extends inside the holder body along the longitudinal axis, and which has a first cavity end at a first holder body end. The damping toolholder further includes a tuning mass, which is movably arranged inside the cavity and extends along the longitudinal axis, and which has a first tuning mass end at the first holder body end. The damping toolholder also includes a damping medium, which surrounds the tuning mass inside the cavity, and a single primary spring element, which is positioned inside the cavity. An outer spring element end is immovably fixed to a first cavity end at the longitudinal axis, and an inner spring element end is immovably fixed to the first tuning mass end at the longitudinal axis.