The frictional behavior of some of the compounds for barrel finishing is examined by a four-ball apparatus. With compounds for cutting, the coefficient of friction is high and lubrication breaks down under comparatively low pressure. Whereas, with compounds for finishing, the coefficient of friction is low and lubrication breaks down under high pressure. The relationship between pressure and frictional torque is automatically recorded as shown in Figs. 3-7 so as to examine frictional characteristics.

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Physical and chemical properties of nickel-phospher alloys prepared by chemical- and electroplating, have been investigated, and the data on electric resistance and anti-corrosion property of these alloys are herewith reported. The electric resistance of electro and electroless deposits of nickel containing phospher increases proportionately with an increase of phospher content in nickel, and is higher than in the case of pure nickel. Corrosion resistance of the deposit by chemical plating is superior to that by electroplating and that by electro-chemical plating of pure nickel, but the quantity of phospher has nothing to do with the property of corrosion resistance.

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Behavior of various anodes, electrolysed, depolarized, and carbonized, was investigated in nickel barrel plating and in bright nickel plating.
The result is as follows:
(1) In barrel nickel plating under normal operation, change of component of bath is not due to passivation of the anode, but to excess dragging out of the solution.
(2) In barreling, corrosion of anodes was as good as in still nickel plating. The surface corroded was smoother at 4A/dm² than at 2A/dm² of anode current density.
(3) Respective anode potential in plating with each brightener added was higher than without brightner, due to adsorption on anode surface of brightner.
(4) Qauntitative measurement of anode potential in bright nickel plating was difficult to obtain any value, due to its poor reproducibility showing only qualitative significance.

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Chemical dip polishing action in the newly presented bath of dehydrated phosphoric acid (DPA) added with some organic solvents were investigated.
Appearances (smoothness, pitting and colouring) of the metal surface polished chemically in the above mentioned bath were observed, and the corrosion loss of the polished was also measured, taking the experimental conditions, such as bath composion, temperature and dipping duration, into consideration.
(1) Brightening action for steel was obtained by using the baths composed of 10 parts of DPA (concenterated up to P₂O₅ 78%) and 1-5 parts of such organic ingredients as alcohol, ether, keton, organic acid anhydride and their derivatives.
(2) It was found that these baths had the following characteristics compared with the conventional one which contains inorganic reagents besides DPA:
a) Smoothing action was more effective for steel,
b) The lower optimum temperature was found between 60 and 100°C,
c) Corrosive behavior of steel was so small that the corrosion loss of the material immersed in this bath was reduceded to approximatly one half of that treated in the conventional bath.
(3) Some Organic compounds added to DPA seem to contribute to strengthen the activitiy for steel and to improve the ability of making flexible, porous film available for smoothing action of the bath.

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Study on electropolishing of copper and copper alloys was begun by Dr. P. A. Jacquet in 1935, but it is not so popular as chemical polishing, that has been commercially used to obtain good luster to be applied as plating base.
Moreover, Dr. Jaquet's electropolishing solution containing phosphoric acid is quite effective for single phase copper or 7.3 brass, but not for the bronze containing tin alloy or two phase 6.4 brass.
Various kinds of electropolishing solution were tested for these alloys and polishing effect of phosphoric acid-chromic acid, and phospholic acid-chromic acid-sulfuric acid were found to be remarkable for various steels, aluminum alloys, etc. Characteristic curves of anode current density-bath voltage for the metals such as aluminum bronze, brass, tin bronze and nickelsilver of different heat treatment, were plotted to investigate and compare the polishing effect.
1) Aluminium bronze
Polishing of 6% Al bronze of solid solution of single phase is easy; but during polishing selective solution and pits so easily take place that cast material gives rise to casting segregation while solidifies. Polishing of 10% Al bronze of two phases of α+β is difficult, but that of quenched β phase of martensite needle structure is easy.
2) Brass
Polishing of 20%, 30% zinc brass of single phase is easy, but crystal structure occurs at low anode current density, pit appears at high anode current density, and dezincation will take place in a long run.
Polishing of 40% Zn brass of two phase of α+β is difficult but brilliant smooth surface is. obtained of quenched and annealed materials or low anode current density, while its dezincation is remarkable at high anode current density than in the case of 20%, and 30% Zn brass.
3) Tin bronze
Polishing of 4%, 8%, ahd 12% tin bronze of single phase is easy, but the more the content of tin increases, the more difficult becomes the polishing of low anode current density. Polishing of bronze containing over 15% tin of α+β phase, its β phase being of martensjte needle, is comparatively easy. Moreover, it is considered that the polishing effect is improved since the contained tin is dissolved by sulfuric acid in the polishing solution.
4) Nickel-silver
Polishing of nickel-silver of single phase structure is easy, and good polishing surface is obtained.
Electropolishing solution added with oxidizer (chromic acid) is superior for polishing to that without oxdizer, even in the two phases alloys. Moreover, the addition of sulfuric acid improves the electropolishing effect, preventing the formation of insoluble salt of tin in tin bronze.

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Nickel-electroforming is used for obtaining a nickel-replica by means of electrodepositing nickel on a mold.
In recent years, electroforming technique has made great progress, yet there remained some difficult problems to be solved.
Of these problems, it is most essential for electroforming engineers to find out suitable methods for separating the electroformed shell from mold.
By this study, it was revealed that the high tensile stress, generated in the electroformed nickel, might oppose to the separation of the electroformed shell from mold.
It was also observed that, if the electroformed Nickel has extremely low tensile stress or compressive stress, the electroformed shell might easily be separated from mold.

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