Is 904L Stainless Steel Expensive
904L steel is more expensive and much more complicated to machine because of it's hardness. Rolex had to replace most of their steel production line and tools to be able to handle the change. It helps that they make all their parts in-house, most other brands have to get cases made by outside suppliers. 316l is very corrosion resistance but not as resistance as 904l but 904l causes nickel allergy in some people so watch makers apart from Rolex avoid it.