Kong,
I don't know the real reason "functionally" for using normal stainless steel 316L compared with 904.
Maybe they don't see added advantage of sea-water resistance despite it's 100m water resistance rating?
My suspicion is that they kept to the "medical grade 316L steel" because that is in keeping with medical functions.
Regards, MTF
This message has been edited by MTF on 2008-03-05 09:18:02