Tungsten Carbide Black with Blue Bevel Edges and Silver Centre Line Ring. Available in Size W. Approximate Dimensions: 8mm Width. 'Tungsten' is derived from a Swedish phrase meaning 'heavy stone' in honour of its weight and strength. On its own tungsten is brittle but when chemically bonded with other elements it becomes 'Tungsten Carbide' which is then a metal alloy with superior strength, hardness, and durability. It rates 9 on the 'Mohs' scale of minera...