Described herein is an electric discharge machining (EDM) assembly having an EDM electrode capable of machining multiple regions of a valve seat within a valve body. The electrode includes two cutting surfaces that are separate from each other. The EDM assembly is capable of removing material from a first region of a valve seat while moving the first cutting surface in a first direction and capable of removing material from a second region while moving the second cutting surface in a second direction.

According to various embodiments of the disclosure, an electronic device may include: a housing, a processor disposed inside the housing, the housing may include a metal member comprising a metal and including a first convex and concave pattern formed in a shape corresponding to a shape of a second convex and concave pattern formed on a jig, wherein the jig is formed for use in electro chemical machining (ECM), and the first convex and concave pattern may have at least a portion formed at a substantially uniform pitch and a substantially uniform height.

A power delivery and control system for an EOT machine. The system has component assemblies assembled in a densely packed array. Each component assembly including one or a sub-set of a power delivery system and a servo-controller to control a servomotor assembly linked to, and orientated coaxially with, an electrode.

This invention is directed to a pattern transfer device and assembly for mass-transfer/fabrication of micro-sized features/structures onto the inner diameter (ID) surface of a stent. This new approach is provided by technique of through mask electrical micro-machining. One embodiment discloses an application of electrical micro-machining to the ID of a stent using a customized electrode configured specifically for machining micro-sized features/structures.

A boring cutter body (5) is inserted into a circular hole (3) and is rotated and moved in an axial direction, whereby screw-shaped groove parts (11) are formed by using a tool bit (9) provided on a tip end of an outer peripheral portion, and broken surfaces (15) are formed by breaking tips of ridge parts generated by formation of the groove parts (11). Moreover, the groove parts (11) are processed through electric discharge machining using a wire electrode (17) provided to the boring cutter body (5) behind the tool bit (9) in the rotating direction, thereby forming finely roughened portions (41) having more finely roughened shapes than the broken surfaces (15).