Using Nishihara's wear testing machine, the wear resistance of the Cr deposit was measured changing the combination of various metals.
1) When Cr was combined with bronze, Cr surface became coarse, which might be accounted for the fact that bronze particles, floating in the used lubricant oil, were melted owing to the frictional heat and penetrated to the Cr deposit.
2) In the case of Cr deposit against carbon steel, the latter was covered with thick Fe₃O₄ layer and reddish brown iron oxide adhered to the former without lubricant. By employing oil as lubricant, pitting wear of fatigue was observed on the carbon steel.
3) In the case of Cr against cast iron, wear loss of the cast iron was large, and graphite adhered to Cr without lubricant. Wear loss of the Cr deposit of low hardness plated under certain condition or treated at certain temperature was small with lubricant oil.

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A method of analysis of alkaline descaling solution containing sodium hydroxyd, sodium cyanide and “Chelate compound” was developed.
A satisfactory result was obtained by titrating EDTA with Ca⁺⁺ using NN as indicator, calculating sodium cyanide by Liebig method and titrating sodium hydroxyde with an acid using indigo-carmine as indicator.
Consumption of sodium cyanide of descaling solution in action is considerably great, amount of sodium hydroxyde is apt to increase, but the EDTA remains constant.
Effect of descaling, consumption of sodium cyanide and increase of sodium hydroxyde vary depending upon the wave types of the current.

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An investigation was made as to the possibility of anodic dissolution and electropolishing of Al, Cu and Fe in the formamide bath. Al dissolved anodically in the bath containing Cl^-, I^-, Br^-, ClO₃^-, ClO₄^-, etc. but in the bath containing NO₃^-, PO₄^3-, CO₃^2-, SO₄^2-, (COO)₂^2-, SO₃NH₂^-, BO₃^3-, etc. anodic film was formed.
Al was well polished in the HCONH₂-NH₄ClO₄ bath, and tests were made about the effect of salt concentration, temperature and stirring of the bath.
Addition of water more than 15% by volume inhibits the polishing effect.
Cu and Fe dissolve anodically in almost all the baths, but resulting in the formation of pits and rough surfaces.
Anodic reactions of these metals in various baths are divided into three groups. It might be deduced that in formamide bath the electropolishing mechanism is similar to that in aqueous solutions.

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