Spring Steel Bones are also known as "white" bones, this is for the obvious reason; they are white. The white however is only a plastic like nylon coating that protects the steel and inhibits rust. Spring steel bones should be quite rigid; able to flex but not easily bent. They flex only forward and back not from side to side. The thickness of the bone is very important, more so than the width. Our spring steel bones come in more than one thickness to accommodate as many needs as possible. The standard or most popular size is series #50-8206-_ _; these are 6mm wide X .6mm thick and come in various lengths. (6mm is equivalent to approximately 1/4 inch) These are the most rigid of the small bones. We also stock a slightly wider bone; 8mm wide but only .4mm thick so despite being wider it is more flexible as it is not as thick. Both these bones come in several lengths measuring from 10 cm up to 42cm and these are the most commonly used spring-steels. Garments made with these bones can be hand washed; never put any boned garment in a washing machine. Spring steel should be used down center back of all corsets.