Some necessary properties required of the compounds generally used in barrel finishing are investigated.
The result obtained is as follows:
(1) The compound with good lubricity is suitable for brightening and polishing soft metal except iron and steel, s. g. copper alloys or zinc alloys. But the lubricity is not necessary for deburring and cutting of iron and steel.
(2) In barrelling, chemical polishing is unnecessary, but the compound which produces phosphate film on iron and steel is effective to improve the abrasion.
(3) pH value of the compound solution must be maintained within the range not to corrode the base metal.
(4) Surface tention of the compound solution has nothing to do with the finishing effect.

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The bond strength and adhesiveness or toughness between sprayed coatings of 13 Cr stainless steel (about 1.5mm thick) and the base metal of 0.2C mild steel prepared by spraying with molybdenum, by electric bond method with nickel or by steel grit blast, were determined by the tensile test method as previously reported.
The results obtained were as follows:
(1) The maximum value of bond strength was about 8kg/mm for the coating prepared by spraying with molybdenum and about 6kg/mm for the coatings prepared by electric bonding with nickel (using 400Amp.) or by grit blasting.
(2)The maximum value of adhesiveness or toughness was about 0.8kg·m/cm² for the coatings prepared by spraying with molybdenum or by electric bonding with nickel, and about 0.5kg·m/cm² for the coating prepared by grit blasting.

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Internal stress of electro-deposit was measured by electric resistance wire type strain-meter for the purpose of obtaining the deposit of low internal stress in nickel electroforming.
Though this method had some points to be improved, was practically satisfactory to get absolute value as expected in nickel electroforming.
(1) Extension stress is found in the deposit in nickel sulfamate bath, and the deposit of low internal stress is obtained under the condition for high hardness deposit.
(2) Primary brightner generally reduces the internal stress of the deposit, but increases by adding sodium benzil napthalen sulfonate to the bath.
(3) It is possible to reduce the internal stress to zero in nickel sulfamate bath including nickel chloride.
(4) Some reagents of secondary brightner decrease the internal stress of deposit in proportion to the increase of other additional reagents.

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Brenner and Senderoff's Contractometer type stress meter was experimentally made reconstructing spiral type thermo regulator.
Using this stress meter, the stress of electrodeposits in Watt's type bath was measured.
The results is as follows:
(1) Errors of stress measurement by this stress meter were within ±5%.
(2) Rate of increasing the thickness of electrodeposits owing to decreasing of stress in electrodeposits were almost the same ratio as those published by Kushner or other authorities, and it was confirmed that this phenomenon is caused by increasing grain size of particles of the electrodeposits.
(3) Measured electrodeposit stress did not vary largely no matter whether the base metal of spirals was made of steel, copper or brass, of different Young's modulus.
(4) Thickness of the spiral of base metal may well be as large as to be enough sensibile to the pointing needle.
(5) So far as the surface of base metal of spirals is concerned, in case of the mechanically polished state, the stress was not affected, but in case of the state treated by FeCl₃-HCl or other chemical solutions, the first electrodeposit stress was pretty small.

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The matted and pitted surface of metals had conventionally been utilized as decoration. But, recently, it has become to be used for optical, and precision instruments, etc.
Pitting on metals is practically formed by sand blasting, wire wheel scratching, chemical etching methods, etc. These methods, however, affect the quality of material, and some pre-treatments such as leveling, polishing, cleaning, etc., and post-treatments such as bright finishing etc. are required. Pitting frequently formed during chemical and electropolishing is considered deteriorate brightness, however, these would be good methods to be utilized to get desired matt surface.
The author compared the shape of the pit by the said ordinary method, with that by electropolishing method, and observed the mechanism of formation of pits by the latter.
The summerized results are as followes;
(1) The shape of the pit by the ordinary methods is complicated, but that by the electropolishing method is of almost complete circle.
(2) The surface besides the pits by electropolishing is smooth and even, which will make possible to do without pre- and post-treatments.
(3) The shape of the pit formed under the anode current density and bath voltage for bright surface, is of circlet, but that for rough surface, is complicated due to selective dissolving by local attack of the electrlyte.
(4) The size and distribution of the pit formed under the condition of smooth surface, are affected by the state of bubbling oxygen from anode, i.e. by anode current density and bath voltage.

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Stress in electrodeposition was measured by means of the same equipment as described in the first report, and under various electrolytic conditions using Watt's type bath, plain bath, all chrolide bath, and sulphamate bath.
The result is as follows:
(1) Effects of temperature, current density, pH, Ni⁺⁺, and Cl^- on the stress were almost the same as reported by Brenner and others. The value of stress in Watt's type was the lowest when H₃BO₃ was about 30g/l.
(2) MgSO₄⋅7H₂O of 0-200g/l or Cu⁺⁺ and Zn⁺⁺ of 0-0.05g/l had almost nothing to do with the stress.
(3) Some organic impurities increase the stress.
(4) When Watt's type bath or all chloride bath was air-agitated, the stress was increased about 7×10³ p. s. i.

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