IWC Platinum Cal 89

In the 1960s Isomura, who were the Japanese distributor for IWC watches, produced a small number of platinum cases for the Japanese domestic market. These cases were made in Japan in order to avoid the prohibitively high tariffs on importing platinum cases from Switzerland.

Platinum watch cases are extremely uncommon, especially for a man's watch. This is partly due to the inherent difficulties of working with the metal, which is much harder than gold. The advantages of platinum for a watch case are that it is hard as a metal and resistant to scratching and so forth.

The serial number of the case dates it to around 1960, the movement is the calibre 89. Developed in 1946 by famed IWC Technical Director Albert Pellaton, the Calibre 89 is an extremely accurate, mechanical three-hand movement with central seconds.
 
Maker: IWC
Year: Circa 1960s
Material: Platinum
Dimensions: 35mm diameter; 9.5mm thickness
Crystal: Plexiglass
Lume: No
Caliber: IWC, self-winding, caliber 89
Lug Width: 17mm 
Box/Papers: No