A spring cutting tool, which is used for finishing of metal surface, is one of the most typical elastic tools. However, there are very few reports about the cutting characteristics of spring cutting tool. In this paper, the residue of cut, the relationship between pre-determined depth of cut and actual depth of cut, and so forth are investigated under the repeated cutting by the use of the simplified spring tool as cantilever-type.
The main results are as follows :
(1) At the same number of cut, the accumulated actual depth of cut of large rake angle is larger than that of small one.
(2) The residue of cut is approximately in agreement with the edge displacement in the cutting-beginning-point.
(3) The residue of cut does not depend almost upon the rake angle, but upon the relief angle.
(4) The results of the experiments agree approximately with the analysis.

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In this paper, it is defined that the failure criterion of coated abrasive belts under constant force plunge grinding is the time when the stock removal rate is reduced to zero and under fixed feed plunge grinding is the time when the normal grinding force reaches to the specified value. Then the tool-life equation is derived theoretically on the basis of the metal removal mechanism and wear process of coated abrasive belts which have been reported in the previous papers. This tool-life equation may be considered to be the one which introduces the initial wear into the Taylor equation. And then stock removal during a belt life, the machining cost and the time to change belts are theoretically and experimentally investigated. As the result, optimum conditions of belt grinding on the total stock removal and the machining cost are reasonably determined.

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In this paper, for the purpose of clearing the elastic behavior and the elastic contact between the contact wheel and the workpiece in the cylindrical grinding by the coated abrasive belt, the amount of its radial expansion, the depth of over cut and the normal stress distribution on the contact zone are analyzed experimentally. The cylindrical plunge grinding is applied and the stress distribution on the interface is analyzed by the photoelastic coating method. Main results obtained are as follows :
(1) The amount of radial expansion of the contact wheel with the centrifugal force increases exponentially from the center of it towards end, and its peripheral surface is in concave. The experimental results of the depth of over cut approximately agree with the values calculated by introducing the apparent modulus of dynamic elasticity of the composite (of coated abrasive belt and contact wheel) into the theory of the amount of radial expansion.
(2) The normal stress distribution applied to the cutting edge on the coated abrasive belt has a parabolic form for the various contact wheels in the state of rest or grinding.

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The mechanisms of contact and friction between two rough surfaces are analyzed, assuming that the asperities with which the surfaces are covered, at least near their summits, are spherical and they are contacted elastically one another.
The main results obtained are as follows :
(1) The real contact area and the number of contact spots are approximately proportional to the load, but the mean area of contact spots and the mean pressure at the contact areas are almost independent of it.
(2) The frictional force F is nearly equal to s·Ar, where s is the shearing strength at the contact areas and Ar is the real contact area.

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There are many discrepancies in opinions hitherto about the probability density function of cutting edges after dressing treatment. The present paper deals with the effect of the dressing treatment on the grinding wheel and ground surface. The theoretical explanation was offered for the distribution curve of cutting edges after dressing and the root mean square roughness of ground surface. The calculated values based on the theoretical explanation show good agreement with experimental values. The theory shows that when the grinding wheel is dressed by the diamond dresser with a conical apex, the distribution curve of cutting edges changes from the rectangular distribution to the parabolic one with the increase of the dressing number and the root mean square of surface ground with it can be calculated theoretically.

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From the reconsideration of the merits and demerits of the corner roundness which has been conventionally made at the junction of major and minor cutting edges of cutting tool, it is suggested that the omission of the corner roundness may bring several advantages.
Turning tests of carbon steel with the cutting tools of varied shapes prove the following advantages : Cutting tool without corner roundness
(1) can make the surface finish smoother than that theoretically expected,
(2) can avoid the wear at its end cutting edge or profiling edge, and accordingly, can keep the initial surface roughness for long cutting time, and
(3) tends to produce shortly broken chip in wide range of cutting conditions. Namely, this tool is superior to the conventional cutting tools in the convenience of chip disposal, especially in light cutting.

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In order to investigate the correlation between surface nature of grinding wheel and its ability of grinding, an apparatus for measuring the apex shape of abrasive grain in the surface of grinding wheel is built up by way of trial. The apparatus enables to obtain the distributions of normal direction and area of the apex surfaces by projecting a fine laser beam to the wheel surface and detecting the reflected beam from the apex. The results of measurement with the apparatus are compared with the directly obtained profiles of the wheel surface and the ground surface by the wheel The results are further compared with the apex shape obtained by the reprica method. It is then confirmed by the comparisons that the results with the apparatus are fully consistent with the real state of the wheel surface. Material of abrasive grain, sharpness of diamond dresser and feed rate of dressing appear to greatly influence on the nature of the wheel surface and these influences are detectable with the apparatus in the present paper.

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