The stainless steel tube Lochhardness test is the same as the Breitbart hardness test, which is the indentation test method. The difference is that it measures the depth of the indentation. Rock's hardness test is a widely used method, in which HRC is second only to The B.C. in the steel pipe standard. Rock's hardness can be applied to the determination of very soft to very hard metal materials, it makes up for the Bress method is not, compared to the Breitbart method is simpler, can directly read the hardness value from the hardness machine dial. However, because of its small indentation, the hardness value is not as accurate as the Buchmethod.