A newly designed portable wear testing machine is presented in this paper. The spherical rotating wheel of this machine is impressed on the flat surface of the test piece under the load which is increased in proportion to the increase of the contact area between the rotating wheel and the test piece, and therefore the mean contact pressure is constant notwithstanding the increase of the depth of the impression. The load is applied by means of an electro-magnet, and hence the more deelply the wheel is lowered into the wear track of the test piece, the less the gap of the electromagnet and so the heavier the load. It is investigated theoretically and experimantally that the pressure varies little during test. The wear amount is estimated by measuring diameter of the wear impression microscopically. Microwear volume can be detected by the machine within a short time. The machine is portable (about 6 kg) and can be fixed on a large test piece.

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The vibration of the head of Japan-made sewing machine (DDW-Type) in its working condition is measured and discussed. It is mainly excited by the unbalance forces which are due to respective motions of five parts such as needle, needle holder, balance weight, needle crank and thread take up lever. Both the motions of the needle and the needle holder are not of pure sine form, but contain some higher harmonics. The unbalance force caused by the fundamental wave motion of the needle is well cancelled by the forces which are due to the balance weight and the other machine parts. The unbalance force generated by the higher harmonic motion of the needle, however, cannot be cancelled by them. For this reason, therefore, its relative magnitude to that of the force caused by the fundamental wave motion becomes large.
As the natural frequency of the head of the machine becomes 60 cps., the resonance phenomena of vibration of the head can be seen when the machine runs at the speed of 3600 rpm. Of course, this vibration is due to the unbalance force of the machine. The unbalance force, moreover, contains the 2nd harmonics of relatively large intensity, and therefore another resonance takes place when the machine runs at the speed of 1800 rpm. These theoretical results are explained by the observation of running phenomena of the machine.

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The effects of tool material upon machinability in terms of chip formation and cutting force have been investigated experimentally. Although the effect has been considered to be negligible or very slight, it has been clarified to be appreciable for some work materials such as brass, copper, aluminum, etc. According to the close investigations, it has been verified that the reason for this can be attributed to the difference of tool-chip contact length which will be basically controlled by the chemical affinity or the work of adhesion between tool and work material rather than to the temperature difference on the tool face due to the difference of tool material.

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Paper phenoiic laminates (P 4 A, P 3 B, P 5) are blanked and pierced by circular punch and die of 32, 6, 3, and 1.5mm in diameters. In this experiment, shearing and stripping resistance, punch stroke are recorded by an inkwriting oscillograph, and dimensions of sheared edge, depth of surface crack and bulged height around the pierced hole are measured by a projector, and finally diameters of the sheared blanks and pierced holes are measured by a comparator. As the sheared conditions, seven factors, i.e. clearance between punch and die, heat temperature, heat time, clearance between punch and stripper plate hole, punch and die size, material, punching interval are chosen. Consequently it is summarized that the clearance (punch and die), heat temperature and hole size have the greatest infnlence upon the measured items and effect of the other four factors are little. Provided that the clearance is smaller, above two resistances are higher, but good edge is obtained and the blank size approaches to the die size. Elevating the heat temperature, resistances are reduced but shrinkages of the hole and blank are increased. When hole size is small, especially smaller than five times of thickness of material, bulging around the hole and stripping resistance are increased rapidly but shearing resistance is reduced.

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An investigation has been made on the effects of the collimation and oblique incidence of light on the interference fringes, in applying the corner-cube interferometer for measurement of length by the method of fringe counting. It is found that the visibility of interference fringes is affected by the lateral and longitudinal shift of the moving corner-cube prism, and when the direction of incident beams on the interferometer is not parallel to the direction of longitudinal shift of the moving prism, the measured lengths have the error which is function of both shift and the angle between these directions.

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In this report, the method of examining the stylus roughness meters by means of frequency response is explained. Especially, the results of examination by a roughness reference specimen are shown.

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In order to find out the method of hot machining which is of high efficiency and simple, we examine following two methods. i.e., (1) Hot machining by heating tool; By this method heat is supplied from tool to workpiece. (2) Hot machining by electric heat; By this method the tool and the workpiece are connected to electric source and they are heated by electric current directly.
In this paper the effect of hot machining by heating tool is analyzed theoretically and examined experimentally by nylon as workpiece material. It is clarified this method is so effective on reducing the cutting force and on increasing the shear angle, and their effects are explained from theoretical consideration.

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