In the first report the published papers on the fatigue strength of rolled screw threads were reviewed, and it was reported that the fatigue strength of rolled screw threads might be affected by the rolling condition. Then the process of thread rolling was analysed theoretically. In the second report the results of the rotating bending fatigue tests on the specimens with rolled V groove were presented. In this experiment the rolling conditions of V groove were changed by varying the number of revolutions of specimen during rolling process. The type of rolling pressure curve was held constant. In this third report the results of the fatigue tests similar to those in the second report are presented. In this experiment the type of rolling pressure curve as well as the number of revolutions of specimen is varied. When the rolling is performed by the usual method using the rolling attachment reported in the second report, the rolling pressure curve becomes an increasing pressure type. Using the same attachment the constant pressure type can be obtained by a simple additional operation. In these two types of rolling pressure curves the V groove is rolled at the three levels of the number of revolutions of specimen. The fatigue tests are carried out on these specimens. The fatigue strength of the specimen with rolled V groove increases with the decrease of the number of revolutions of specimen, and is higher in the constant pressure type than in the increasing pressure type.

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The purpo e of the present study is to obtain the rolling-stress distributions due to the rectilineal and circular grooved rolls. In the first report, the author investigated the three-dimentional distributions of rolling stress in regard to flat rolling process. In grooved rolling process, generally, most of materials are rolled restricting the lateral spread due to the roll sides. So, it is very difficult to find the general solution of rolling stress as compard with flat rolling process. The author adopted a simple experimental result and obtained the three-dimentional stress distributions during the rolling in the case of the materials were rolled at the entry side holding the plane.

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In this paper the analysis of complex motion in cam mechanism is carried out by new graphical methods which illustrate easily the "actual" displacement, velocity and acceleration of followers, and the errors in Thomson's method which were solved erroneously by means of vectors are pointed out. For the limited and allowable pressure angles of cam, moreover, the authors present convenient methods for graphical solution.

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The condition of active surface of a grinding wheel changes slightly or considerably in the process of metal grinding. The flank wear of cutting edges of grains widens the contact areas between grains and metals, and deteriorates the cutting ability of the wheel. On the contrary, the fracture and tearing-out of grains compensate the deterioration. The latter is so-called self dressing. In this report, the process of widening of the flank-wear area of grains in grinding, which is the result of both effects, the deterioration and the compensation, was analyzed under certain simple assumptions. An equation obtained in the analysis revealed a good agreement with the experimental data. Predictions on the characteristics of grinding wheels, which were derived from the equation, were illustrated.

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It is expected that a twist drill will give somewhat different aspects on the deflection and stresses compared with a straight bar of the same cross-section. In the first part of the present research, we proved theoretically that the deflection of a twist drill due to bending becomes a particular space curve. The surface stresses of the drill due to torsion, obtained experimentally by the strain gauges, are shown in this report also.

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To determine the effects of cutting conditions on flank adhesion, nodular cast iron grade 60-45-10 was machined dry and wet with carbide cutting tools, cast iron cutting grade and steel cutting grade. Decreasing the feed rate raised the critical cutting speed at which flank build-up occurred and lowered the resultant tool force. For tools with positive rake angle, the critical cutting speed was generally higher and tool forces were lower than for tools with negative rake angle. Large clearance angle eliminated flank adhesion. The use of cutting fluids prevented flank adhesion, and tool force patterns were smooth and smaller than those for dry cutting. Flank build-up was ana1yzed chemically and metallurgically. Methods to prevent flank adhesion were recommended.

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It is well known that the rate of wear is mostly very high at the beginning, but later decreases to a lower constant value. The mechanism of these transient phenomena of wear has never been clear. This paper deals with the relation between the initial wear and stationary wear. Special wear machine was made for this purpose. The experiment was made on the test piece steel in vacuum. The tests revealed that the hard surface part was very important.

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An experimental study of friction and wear under graphite-air mist lubrication was made using mild steel specimens. And the results obtained are as follows : Operating load is limited under the graphite-air mist lubrication, and under an over-load the wear or surface failure occurs. Under the limiting load, effective lubrication is possible, and the coefficient of friction decreases with the increase of load, but is little affected by sliding speed.

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In order to investigate the pitting phenomena, the heat treated gears of 0.35 % carbon steel and the induction hardened pinions of 0.40 % carbon steel were tested with the gear endurance testing machine under the various loads and lubricating conditions. It was observed that, if the loads were beyond a certain value (endurance limit), the pitting grew rapidly with the cycles of load repetition, and the involute errors and dynamic loads of gear teeth increased along with the growth of pitting, and if the loads were below the endurance limit, the pitting appeared to grow only to a certain extent but not any further, and in this case the involute errors and dynamic loads changed little. It is noteworthy that the viscosity of lubricants and the peripheral speeds of the gear remarkably affect the endurance limit.

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The chattering of machine tools is a kind of self-excited vibration, and it is essentially a problem of dynamical instability. A lathe tool under working conditions can be regarded as a dynamic system which, for certain values of its system parameters, becomes unstable and bursts into oscillations. The system parameters are determined by the static and dynamic characteristics of the machine tool structure, the geometric shapes of the tool, and the working conditions. The causes which results in chatter or chatter-free machining are the interactions of these parameters. In this 1st report, the theoretical study is developed basing on the theory of stability criterion, and the results are presented in a form of a stability-chart which gives those cutting speeds at which, for the given values of system parameters, chatter-free machining is ensured. These stability-charts are affected by the interaction of the present motion and the chatter mark produced during the preceeding revolutions.

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The 1st report of this subject was concerned with the theoretical study of the chatter vibration of work pieces in turning. In this 2nd report, the amplitude and the frequency of chatter vibration are obtained. The chatter vibration is considered to be influenced by the chatter mark produced during the preceeding revolutions, and the orderly and characteristic patterns of chatter mark are produced by the interaction between the present motion of work pieces and the chatter mark produced during the preceeding revolutions. Whether the chatter vibration of lathe tools belongs to the softgeneration or the hard-generation depends upon the cutting conditions.

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The 1st and the 2nd reports of this subject were concerned with the theoretical and the experimental study. However, the present report is concerned with the experimental investigation of the stability chart which gives those cutting speeds at which chatter-free machining is ensured, and the comparison with the theoretical results. As a result, it may be established that the greater part of the causes of machine-tool chattering is the dynamical instability of the systems.

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Chatter vibrations occurring in machining metals are of two kinds, forced and self-excited. The existence of each chatter is a serious problem, because it is detrimental to the life of tool, on the surface finish and etc. In order to prevent such chatter, some attempt has been made recently to apply a damper to machine tool. In this paper, the effect of Lanchester Damper for the prevention of each chatter was first examined theoretically, and the procedure of designing damper by which each chatter was effectually eliminated was discussed for any vibratory system. Then, the above theory was ascertained experimentally on a boring quill coupling with Lanchester Dampers. Consequently, it was made evident that the damper which was designed in optimum conditions had a conspicuous effect on the prevention of each chatter.

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This paper deals with a theoretical study of the production system of machine shop on the basis of the Markov process and the information theory. It includes a simple example and a basic flow chart for a digital computer.

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