At the experiment of strain determination by brittle coatings, the authors found that the crack patterns of the coating on a specimen vary with the velocity of loading the specimen, even if the specimen is subjected to constant strain and the drying condition of coating on its specimen is constant. Then we investigated the experimental results at a standpoint of the view that the compositions of coating are chiefly synthetic resin.

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The fatigue strength of metals under room temperature has been investigated considerably well, while the strength under high temperature has not so actively been researched yet.
In spite of this fact, these days it has been more and more important to study about the strength of metals under high temperatures in accordance with the development of gas-turbines and eqipments which are operated under high pressure and high temperature.
As a matter of fact, it will serve the design of various machine parts exposed in the above state to clarify the fatigue strength in elevated temperatures.
For this purpose, this paper deals with the experimental results of the fatigue tests under rotating bending stress, using the specimen of carbon steel with two different carbon contents viz. 0.63 and 0.13 percent carbon.
The fatigue tests were done under the conditions combined with following facters, namely
1) temperature: room temperature, 300°C and 530°C.
2) speed: 1000rpm and 2500rpm.

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This paper deals with wire drawing-process in consideration of friction on the contact surface between die and wire rod. In the procedure of analysis, we apply the theory of shearing strain energy as the condition of plastic deformation, regarding a representative material exhibiting an almost constant flow stress.
We had hitherto investigated on the dies with parabolic, hyperbolic and circular revolution surface, and now we tried to investigate on such a die with elliptic revolution surface to find that the value of drawing stress is mainly affected by the drawing conditions such as the shape of dies, the reduction of diameter, the material of drawn wires, the lublicant and drawing speed etc. As it is very difficult to deal with the effect of drawing speed theoretically, we carried out an investigation under a constant drawing speed to eliminate the effect from different speed.
As the results, we succeeded to express the drawing stress in the functions of the shape of dies, coefficient of friction, reduction of diameter and the flow stress of the wire rod. With numerical calculation we clarify the effects of the drawing conditions on the drawing stress.

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Hevea stocks have been used to produce vibration isolators but recently they are using many synthetic rubbers. Each of them has its own merits and demerits, so by vibration tests we intended to explain and compare their characteristics employing hevea stock F.A.Q. No. 3, neoprene G.N.-A., hycar-OR-25 and silicone, so that we may obtain data to decide what sort of rubber should be used to design isolators.
The followings were examined: (a) influence of temperature, (b) amplitude dependency, (c) oil resistancy, (d) after effect, and (e) others.

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