Portable Take Off Tap Machine Tapping Screws Drilling EDM Drilling Machine 400W Can process stainless steel, hardened steel, carbide, copper, aluminum and other conductive materials, even semiconductor electrical materials can be processed. Mainly removes various diameters of taps, drills, reamers, screws, plug gauges and other tools and cutters broken in the workpiece, using the principle of galvanic corrosion to remove the broken tool, non-contact machining, machining without force, will not damage the workpiece.