Abstract: A machining tool is provided with an electric discharge truing/dressing apparatus comprising a spindle stock for containing and supporting a workpiece spindle which is driven for rotation while holding a workpiece or an electrode; a tool rest which moves parallel and perpendicular to the spindle of the spindle stock and holds an electrode machining tool and a grinding wheel; a feed electricity means disposed between a workpiece supporting portion of the spindle and the tool rest; a magazine disposed at an outside area of a machining area of the tool rest and adapted to store the workpiece and the electrode; and a loading device disposed between the magazine and the spindle. The grinding wheel on the tool rest is subjected to truing/dressing by feeding the electrode from the magazine to the spindle stock.

Abstract: Short, fine fibers having certain aspect ratios and generally triangular cross-section are mixed with particulate material whereby the fibers form a three dimensional network and the mixture is sintered to provide composites containing scattered and enveloped particulate material, which composites have utility as self-lubricating materials or grinding materials.

Abstract: A magnetic attraction system grinding method and apparatus comprised of arranging a magnetic circuit forming means between an abrasive tool and a workpiece, thereby generating a grinding pressure required to grind the surface of the workpiece, and performing the operation of the abrasive tool through a rectilinearly reciprocating movement or rotary movement working along the workpiece surface during the application of grinding pressure while controlling either grinding speed or grinding stroke. The magnetic circuit is produced with an electromagnet or permanent magnet assembly and the abrasive tool may be a magnetic material bonded grindstone.

Abstract: A punching die which may be economically produced is disclosed herein. The die is reinforced by superimposing hard thin plates thereon. The punching die is composed of a die body soft enough to be machined and a thin plate, single or plural, which is harder than the die body. The plate has a hole coinciding with a configuration of a product to be punched. The superimposed plate is characterized in that it remains after a product has been punched out from said thin plate by the die body and the punch. The punching die may be easily operated during production. The procedure involves only slight abrasion of the shape. The device is highly durable and precise and operates without causing curvature in the product. Thus, it is suitable for mass production.