Roy Lewallen wrote:


Don't worry about it. All ferrites are hard, brittle ceramics, but quite
rugged and not easily broken. They're already harder than most steels,
so I don't really believe they're ever coated with a "hardener". I've
seen them coated with an epoxy type material, but assume that's to make
them less porous and abrasive. It doesn't make them any easier to break.


Yes indeed.. they're hard and brittle.. Drop one of those 2.4" toroids
off a ladder onto a concrete floor, and they break.

But other than that, they appear to be pretty tough. The ones I've
gotten don't have any mold flash or lines and are smooth surfaced.