Some watch lovers say that 904L is very hard. In fact, comparing with other material, it is soft. As for 316L, the hardness is even lower. The stainless steel which is really harder is the DSN9 or the steel used to manufacture the Swiss Army Knife.
Some people say that the 904L steel of accurate fake Rolex watches are the most expensive. In fact, the price of well-performed 904L steel is two or three times higher than 316L steel. But the importance of the harness to the case is on the back burner. Corrosion resistance, toughness, easy to process and craftsmanship are much more important.
Many people know that all the 904L steel is manufactured by Rolex. Is that true? Rolex has always kept it a secret. What we are sure is that the 904L steel are provided by Sandvik Company and then Rolex deals it by itself in Switzerland. It is worthy mentioning that the case and bracelet of Rolex Daytona copy with white dial are much more beautiful than other brands. No matter the polished finish or satin-brushed finish, the 904L steel is easier to be blackened than 316L steel.