Throwing power is one of the very important factors in zinc plating. It was determined in various plating baths such as high cyanide bath, low cyanide bath, zinc chloride bath, zincate bath, and pyrophosphate bath by means of Haring-Blum process, Watson process, and Bend cathode process.
The results obtained were summarized as follows:
1) Haring-Blum process was suitable for application in the baths for obtaining uniform plating in a wide range of current density. However, it was unsuitable in the baths likely to produce anodic passivity such as zincate and pyrophosphate baths.
2) Watson process (Hull cell) was a very simple process in handling and of high utility. However, it was difficult to be applied in the baths for dendritic plating, because it gave burning in the part for measuring film thickness.
3) Bend cathode process was suitable for application in the factory and was favorable for measuring film thickness on every face.
4) Cyanide baths had considerably higher throwing power than the various non-cyanide baths. The decreasing order of throwing power of baths was arranged as follows: cyanide baths>zincate bath>pyrophosphate bath. The current efficiency in the above baths was promptly lowered with the increase in current density, and led to higher throwing power.
5) Zinc sulfate bath had low throwing power.
6) The throwing power of zinc chloride bath was higher with the decrease in Zn⁺⁺ concentration and increase in NH₄Cl concentration. It had higher throwing power than cyanide baths when ZnCl₂ concentration was 30g/l or lower.

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Investigations were made on the effects of cold rolling on anode reaction of copper in solutions of 1mol H₂SO₄ and 0.7mol CuSO₄+2mol H₂SO₄ at 25°C.
These experiments were conducted on natural electrode potential, anodic polarization curves, and controlled current electrolysis.
The results obtained were as follows:
1) The hardness of copper and its surface roughness were in creased by cold rolling.
2) The natural electrode potential was less noble with the increase in degree of cold rolling, which suggested that the surface of electrode was more activated.
3) The measurements of anodic polarization curves revealed that the rate of anodic dissolution of the cold rolled copper was higher than that of an annealed copper.
4) The cold rolling of copper plates seemed to be effective in retarding passivity during the electrolysis by galvanostatic method.

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