904L has a LOT more (23 - 28%) more nickel in it than 316's comparatively low 10 - 14%, as some copper - about 2%. It's not particularly more expensive, nor a "higher" grade - it's actually considered a tool steel, and shares most of the same properties as 316L in regards to strength, workability, etc - what it does have that 316L doesn't is increased hardenability via heat treating - this type of steel is used in dies, punches, bending and blanking equipment, etc - it really is a TOOL steel.
Take that for what you will - but with such a high nickel content, I'd be worried about an allergic reaction, and i don't like Rolex anyway.
bo
H T H!!!
