The shearing processes and the properties of the several parts constructing the sheared edge were studied by shearing force-punch stroke diagrams and microphotographs of the section of sheared edge, with the measurements of shape and size for the sheared edge. The results obtained are as follows:
(1) Shearing processes can be classified into four stages, i. e. those of the elastic deformation, the appearance of the first micro-cracks, the appearance of the secondary cracks and the cutting action. The latter three processes are peculiar phenomena to shearing of paper phenolic laminates. In the case of blanking, the first micro-cracks appear in the range of 0.2 or 0.3 to 0.7 or 0.8 of P/P_m (P : shearing force, P_m : maximum shearing force), which may be considered to indicate the elastic fractures of the material. The secondary crack is, here, the general term for the first micro-cracks connected and another kind of cracks, appearing in the range of 0.7 or 0.8 to 1 of P/P_m.
(2) The sheared edge is constructed of the surface of the first and secondary cracks and the cut surface. The process of growth of cracks and the cutting condition are substantially affected by holding conditions of the materials and sheared profiles. Therefore it is the foundamental conditions of obtaining the good sheared edge that the growth of the first cracks is restricted and the cutting process is maintained under the best condition.
(3) In the case that the punch diameter is within 4 or 5 times of thickness of the materials, in other words, in the case of piercing, secondary shearing force appears, and leads to the different shearing process from the general blanking.
(4) The processes and properties of sheared edge at the corner of square blanking are similar to those of piercing, if the corner radius is within 2 or 2.5 times of thickness of the materials, that is, the secondary cracks and grown first cracks cut into the blank, and therefore, sheared edge of the blank is hollowed out in the large triangular form. On the other hand, sheared edge of the hole is covered with cut surface along the most part of its thickness.

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Recently experiments have been attempted with physical and chemical machining to make higher the performance and accuracy of such parts with micro-holes as apertures of electron-microscope and X-ray apparatus, nozzles for internal combustion engine and synthetic fibre manufacturing apparatus, which purpose has never been answered by conventional mechanical drilling. But results of these experiments have all fallen short of our expectations.
Though it has been thought anodic behaviour of metallic surface is only used in surfacefinishing, the authour has succeeded in utilizing it as formative function to "nozzle " micro-holes by devising " electro-nozzle" as a function to gather dissolution in limited part. He set up an experimental device with electro-nozzle of silicaglass as a tool of making microholes and using this device made experiments on the copper, nickel, molybdenum, cobalt, iron and tungsten. He, then, analyzed the function, arranged the types of procedure and systematized the electrolytic process of nozzling micro-holes. This process was found practicable with the above mentioned.
In this paper fundamental experiment was carried on with copper as to the function mentioned above and nozzling condition in four types was analyzed. Characteristic curves of electro-nozzle were surveyed with the same metal by using orthophosphoric acid solution, and explanations were given to the curves through microscopic observations of the phe nomena noted in the nozzle. It has been known that the limitation of electrolytical condition is the insulation phenomenon resulted from the blocking-up of the nozzle by many oxygen bubbles evolved in it. As to the limitation experimental investigations were made on various factors which seemed to have influences on the state of electrolytic reaction and:their results were given.

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