Tin and zinc can be co‐deposited in all proportions from solutions containing sodium stannate, sodium hydroxide, sodium zinc cyanide, and free sodium cyanide, operated at 65°C. and at a cathode current density, for still solutions, of 10–30 amp./ft2. (1.08–3.24 amp./dm2.) using alloy anodes of the same composition as the alloy to be deposited. The tin content of the solution is maintained at 30 g./l. and the free cyanide at 17.5–20.0 g./l. throughout, and the composition of the deposit is adjusted by varying the amounts of zinc, total cyanide, and sodium hydroxide. The most serviceable composition from the viewpoint of the protection afforded to steel is around 78 per cent tin‐22 per cent zinc. Plate of this composition, not less than 0.0003 in. thick, is superior in protective value to either cadmium or zinc plate of comparable thickness, and moreover is extremely easy to solder. With less than 78 per cent of tin the corrosion resistance of the plate diminishes but is not seriously impaired until the tin content falls below 50 per cent. The electrodeposition of alloys containing less than 50 per cent of tin presents greatly increased operating difficulties and it probably is more economical to apply those alloys by hot dipping. Tin‐zinc plate can be passivated by immersion in hot 2 per. cent chromic acid solution. Passivation further increases resistance to corrosion and reduces any tendency toward finger‐marking. The properties and uses of tin‐zinc plate are briefly discussed. The 78 per cent tin alloy is being increasingly used as an alternative to cadmium.