Titanium

A "space age" metal, often having a silver-gray appearance. Because it is 30 percent stronger and nearly 50 percent lighter than steel, it has been increasingly used in watch making, especially sport watch styles. Its resistance to salt water corrosion makes it particularly useful in diver's watches. Since it can be scratched easily, some manufacturers use a patented-coating to resist scratching. Titanium is also hypoallergenic.