Sterling Silver Ruler Six Inches. This Solid Silver Ruler is 15 cm (6″) long, and has milimeters (mm) & centimeters (cm) along one size, and inches along the other side. Hand crafted in the UK by our Silversmith. The Silver Ruler is fully hallmarked, and presented in a box. Also available in a 7.5 cm (3″) ruler. See silver bookmarks, or look for 11M in search box, in variations box, under Silver Bookmarks.