Are 39-545 and 39-546 stainless steel?

Hi. I just ordered 4 pcs 39-545 and 1pc 39-546 to go along with my SS cranks that I already paid way too much from our local Milgard supplier. My question is: Are these also SS? We've had a pretty major problem with the window hardware on the "Lifetime warranted" windows rusting and becoming non functional. Now that I've taken a close look at the project, I also just ordered new SS hinges for 3 of the windows from you.
Thanks,
Bob