A method is provided for removing a fastener having a longitudinal shank from a workpiece using electro-discharge machining, EDM, the method comprising: contacting a portion of the fastener or workpiece with an EDM fixture, thereby: locating the EDM fixture and an EDM electrode relative to the fastener in a lateral direction; and establishing an electrical ground connection to the fastener via the EDM fixture; and eroding the fastener using the EDM electrode.

An electric discharge machine is configured to perform electric discharge machining on a workpiece in a working fluid stored in a work-pan. The electric discharge machine includes: a measurement piping coupled to the work-pan and having an air space inside; a pressure sensor configured to detect a pressure of the air space; and a working fluid supply portion configured to supply the working fluid to the measurement piping.

An electric discharge machine is configured to perform electric discharge machining on a workpiece in a working fluid stored in a work-pan. The electric discharge machine includes: a measurement piping coupled to the work-pan and having an air space inside; a pressure sensor configured to detect a pressure of the air space; and a working fluid supply portion configured to supply the working fluid to the measurement piping.

An electric discharge machining unit capable of stably supplying working fluid to the vicinity of a portion to be machined. The electric discharge machining unit includes a tool electrode, a housing, an electrode guide, and a working fluid supplying device. The housing includes a fitting hole having a tapered surface. A first supply path is formed in the housing. The electrode guide includes a tapered portion and an ejection opening formed on a lower surface. A first flow path is formed in the electrode guide. The tapered portion is configured to be fitted into the fitting hole to connect the first flow path to the first supply path. The working fluid supplied from the working fluid supplying device to the first supply path and the first flow path is ejected from the ejection opening.

An electric discharge machining unit capable of stably supplying working fluid to the vicinity of a portion to be machined. The electric discharge machining unit includes a tool electrode, a housing, an electrode guide, and a working fluid supplying device. The housing includes a fitting hole having a tapered surface. A first supply path is formed in the housing. The electrode guide includes a tapered portion and an ejection opening formed on a lower surface. A first flow path is formed in the electrode guide. The tapered portion is configured to be fitted into the fitting hole to connect the first flow path to the first supply path. The working fluid supplied from the working fluid supplying device to the first supply path and the first flow path is ejected from the ejection opening.

A wire electrical discharge machine controls a second motor unit including motors for feeding a wire electrode in a wire running direction in which the wire electrode extends, so as to feed the wire electrode at a set feed rate during a machining period from a first time point at which the wire electrode moving relative to a workpiece in a direction intersecting the wire running direction is estimated to enter the workpiece, to a second time point at which the wire electrode is estimated to exit the workpiece. The second motor unit is controlled so as to feed the wire electrode at a feed rate lower than the set feed rate during at least one of a first non-machining period from a processing start time point to the first time point and a second non-machining period from the second time point to a processing end time point.

A wire electrical discharge machine controls a second motor unit including motors for feeding a wire electrode in a wire running direction in which the wire electrode extends, so as to feed the wire electrode at a set feed rate during a machining period from a first time point at which the wire electrode moving relative to a workpiece in a direction intersecting the wire running direction is estimated to enter the workpiece, to a second time point at which the wire electrode is estimated to exit the workpiece. The second motor unit is controlled so as to feed the wire electrode at a feed rate lower than the set feed rate during at least one of a first non-machining period from a processing start time point to the first time point and a second non-machining period from the second time point to a processing end time point.

A cutting electrode head for a handheld electrical discharge machining (EDM) device comprising: a housing; a cutting electrode supported in the housing, and configured to move from a retracted position to an extended position along an electrode axis (C) to cut a workpiece; and an actuator supported in the housing and movable along a movement axis (E) which is at an angle to the electrode axis (C), wherein movement of the actuator along the movement axis (E) causes the cutting electrode to move between its retracted and extended positions.

A cutting electrode head for a handheld electrical discharge machining (EDM) device comprising: a housing; a cutting electrode supported in the housing, and configured to move from a retracted position to an extended position along an electrode axis (C) to cut a workpiece; and an actuator supported in the housing and movable along a movement axis (E) which is at an angle to the electrode axis (C), wherein movement of the actuator along the movement axis (E) causes the cutting electrode to move between its retracted and extended positions.

An electrode guide assembly for an EDM process includes a guide tube having a first end and a second end, a fluid feed portion, a fluid return portion, and an electrode. The guide tube has a set of at least two supporting protrusions, with the protrusions projecting radially inwardly from an inner diametral surface of the guide tube. The electrode is slidably accommodated within the guide tube, with an outer diametral surface of the electrode abutting against the set of supporting protrusions. The first end of the guide tube is in fluid communication with the second end of the guide tube to thereby provide a fluid feed channel, and the second end of the guide tube is in fluid communication with the first end of the guide tube to thereby provide a fluid return channel.