Cams With Stainless Steel Axles

Do all cams have stainless steel axles? I am starting to see rust on some of my normal C4's from alpine mixed abuse. I usually take my cams out and air them out after climbing. I know this is just surface rust (not worries about strength here). It just made me wonder what cams have stainless steel parts and which ones don't. I don't see any rust on my ultralight master cams and I think I am starting to see some surface rust on the axle of my baby, a new #4 ultralight c4. 

Do you guys know which cams have all stainless steel parts?

No cam will have all stainless parts, it would be more expensive, heavier for the same strength, or weaker for the same weight. Wild country's new friends have a hollow stainless steel axle which gives you essentially two axles for the weight of one (WC's words not mine)