First, I offer a tip when rotating your carbide bits: Use an impact driver if the bolt doesn't loosen easily.
I learned this tip painfully, by breaking off a a torx wrench flush with the top of a bolt. It was stuck, so I tried drilling it out with a cobalt drill, which only made a dimple. Does anyone know how to remove it?
In case it's relevant, I did this on a Grizzly G0454 5Hp 20" planer.
Any ideas are welcome!