Sinn U1 SERIES, Owner'S Manual, Page: 17 / 35

17
– THE DIVING WATCH
MADE OF GERMAN SUBMARINE STEEL
With the diving watch U1, SINN engineers succeeded in developing a
diving watch in which the quality of material and design gives it superior
resistance to external influences under extreme conditions of use.
In their search for a steel with the desired resistance, the SINN engineers
found what they were looking for at the German submarine manufacturer
ThyssenKrupp Marine Systems.
This special grade of steel is developed by ThyssenKrupp for the outer shells
of the very latest non-nuclear submarines, the 212 class, of the German navy.
Normal case steel has to be rinsed in fresh water after contact with saltwater,
as long-term exposure to saltwater can, in adverse circumstances, lead to
corrosion. Submarine steel, by contrast, is completely resistant to prolonged
contact with saltwater. Also, submarine steel is, on account of its ductility,
extremely resistant to cracking, thereby further increasing its reliability. Its
mechanical strength is more than 1.55 times that of the usual watch case
steel AISI 316L.