Edited 2017-05-26Some razors do, to be polite about it, age less well than others. But when it's a razor that cost me slightly less than 3 US dollars to begin with, a five year service life really isn't bad at all... it's all of 60 cents a year.
When new, the Yuma was shiny, full of promises and very, very cheap.
I must say the Yuma - a cheaply made razor with a hollow handle and paper-thin head all made from "who knows what fell into the pot" zinc alloy - has given remarkable good shaves, wear, tear and oxidation have eaten away the molecule thick "chrome" coating. This means that while the razor is technically usable, it simply don't glide across my manly cheeks with any degree of ease any longer... the whole surface is covered in zinc oxide which is used as an industrial abrasive, in effect the opposite of what you'll want for smooth shaves.
I guess I could ship my Yuma out to be replated by the professionals, possible in something more fancy than plain chrome... but it's not worth doing that with something that is so cheap and cheerful. So I guess it's time to put it back in it's presentation box, put it on the shelf and look for a replacement in my rotation.
Update: Over on my favorite shaving forum a fellow gentleman pointed out that the Yuma might be made from aluminium alloy, rather than the zinc alloy I have been assuming for years. If it is aluminium it's some of the least quality alloy of it I've seen... but that would mean that I could - in theory - repolish the head and get back the original shiny finish. I might give that a go at some point, just for fun.