Never saw that but anyone looking will maybe try bolt, don't move, freeze it and save a lot of grief with heat. It's my age be gentle with me, I don't even buy green bananas anymore.
I always replace most the fixings exposed to the elements with stainless steel ones generally sourced from Ebay. However when it comes down to important ones like disc and calipers bolts I always buy these from Pro Bolt and you can guarantee the quality of the material used. If I was you I wouldn't chance it.
Just apply the rule. No test certificates, no buy. No idea if Pro bolt use traceable and fully tested material, would hope they do. I always ask the question Do you have Mill certicates and testing certs. I cannot tell if a fastener is good by sight alone. Lovely and shiny maybe. No one has a problem until they have one.
