A punching apparatus includes a tool holder unit rotatable around a working axis and provided with a plurality of seats for slidably housing respective punching tools, a beating element movable along and around the working axis and provided with an operating end that has a beating portion to selectively interact with a set punching tool, a first driving assembly for moving the beating element along the working axis to move the set punching tool, and a second driving assembly for rotating the tool holder unit around the working axis. The operating end of the beating element includes a first coupling element and the tool holder unit includes a plurality of second coupling elements, each of the second coupling elements being associated with a respective one of the seats and a related one of the punching tools and being arranged to couple with the first coupling element in a connection configuration.

In a method for manufacturing a laminated iron core from a thin sheet, the method includes coining the thin sheet from below to form a thinned bridge portion on an outer peripheral portion of an iron core piece, blanking the iron core piece from the thin sheet from above or below after forming the bridge portion, and laminating the iron core piece on another iron core piece to manufacture the laminated iron core.

In a method for manufacturing a laminated iron core from a thin sheet, the method includes coining the thin sheet from above to form a thinned bridge portion on an outer peripheral portion of an iron core piece, blanking the iron core piece downwardly from the thin sheet using a set of an outer-shape blanking punch and a die after forming the bridge portion, wherein the outer-shape blanking punch includes a projection portion fitted into the bridge portion when blanking, and laminating the iron core piece on another iron core piece to manufacture the laminated iron core.

A method includes removing material from a die and thereby changing a location of a cutting edge of the die in a punch entry direction and changing a cutting edge cross-section of the die; and assigning a punch and/or a workpiece thickness to the die based, at least in part, on the change in the cutting edge cross-section of the die.

A knockout punch tool set is provided. The knockout punch tool set includes a punch, a die, a draw stud, and a driving tool. The draw stud is configured to be used with both a powered and a manual driving tool. The draw stud includes a driving end with a recess. The recess of the draw stud is couplable to a square drive to allow for use with the powered driving tool. The driving end of the draw stud further includes outer surfaces positioned around the recess to allow for engagement with a manual driving tool. In various embodiments, the punch tool set includes a step bit couplable to the draw stud.

A punching apparatus for forming workings on a workpiece has a punch holder unit, which includes an upper support body rotatable about a working axis, a punch holder body that houses a plurality of upper forming tools and an upper beating element movable parallel to the working axis to selectively interact with an established upper forming tool, and a die holder unit that includes a lower support body rotatable about the working axis, a die holder body that houses a plurality of lower forming tools and a lower beating element movable linearly along and rotatably about the working axis to selectively interact with an established lower forming tool. The lower beating element is movable linearly between an non-operative position, a first operative position, and a second operative position.