The material of hardware shrapnel is quite a lot of material, such as manganese steel, brass, stainless steel, phosphor bronze and so on, the specific choice is to see use environment to wait for a factor. For example for general hardware shrapnel, as long as use cold plate nickel plating is ok, effect can, cost is not high. The metal shrapnel of brass is better than other materials in wet environment, but it costs more. Of course, there are other factors, such as whether to weld or resister, which should be considered.