Silver steel, or high-carbon bright steel, serves as the U.K.'s equivalent to tool steel in the U.S. Manufacturers use these high-carbon alloys to produce knives, razors, drill bits and hand tools. Many silver steel producers manufacture high-carbon steel based on British Standards Institute 1407, which covers testing and composition for this material.
Silver steel contains a high volume of carbon and has one of the highest carbon contents of all tool steels. Manufacturers use this carbon to increase the strength and durability of the metal so that it can be used for applications in which the steel will have to withstand a great deal of wear. According to West York Steel, silver steel contains around 1 percent carbon and up to 0.40 percent chromium, which gives the steel its shiny silver finish. This material also contains other alloys, including up to 0.35 percent manganese and 0.30 percent silicon. It may also feature traces of other materials, such as sulfur or phosphorous.
Silver steel products may feature different levels of hardness, depending on how much carbon they contain and how they are manufactured. According to West York Steel, standard annealed varieties offer a hardness of C27 on the Rockwell hardness scale. The Rockwell scale provides a basis for measuring how well different materials are able to withstand indention when subject to heavy loads. Silver steel can be made with a hardness factor as high as C64 if subject to proper heat treating techniques. During heat treating, manufacturers heat the steel to extreme temperatures, then rapidly cool the material in a water or brine quenching solution. This added hardness gives the steel extra wear resistance but also makes it more brittle.
Manufacturers use cold finishing techniques to give silver steel its characteristic silver appearance. Despite its name and its bright shiny finish, this material contains no silver. According to the Alloy Tool Steel Company, silver steel features very high wear resistance and is known for its ability to hold a sharp edge. It's also easy to shape and machine, which allows manufacturers to form silver steel into very intricate and complex designs.
Like other forms of bar stock, silver steel is sold in the form of long, round bars. These bars share many characteristics with standard drill rod but can be distinguished by their hollow core. According to the G.L. Huyett Company, silver steel is manufactured to very exact tolerances, with very straight edges and parallel sides. These strict tolerances are in accordance with BSi1470, a British Standards Institute publication that specifies exact sizes for silver steel. BSi1470 covers standard sizes for silver steel, which range from rods measuring 3/32 of an inch, or 2 mm, in diameter to those as large as 2 inches, or 50 mm.