I'm building a decent router table fence with adjustable fronts and dust collection. I just routed a 24" stopped dado in some 3/4" plywood. I will be mounting a 24" blue aluminum t track in the dado to hold my hold down fingers on my router table. When I was done routing, I let the router stop and lifted the piece of plywood and not only was the bit smoking (a lot) but there were globs of sawdust glowing very red. I put them out quickly to keep the rest of the sawdust from igniting. I/m glad I wasn't using any dust collection where the red embers would have been sucked down into a sawdust pile! Anyway, do you think my carbide bit is toast? I know you can lose the temper in steel when it turns blue. But what about carbide? It, the router bit, turned black. Randy