I have an emco v10p lathe with the original 4 tool toolpost. Some of the screws in my toolpost have mushroomed where they meet the tool to the point where they are non removable and I cannot put a 1/2 inch tool in at all. The threads are also very tight even when loosening. I’m assuming most of this is from over tightening. Is this normal? Do I take the old screws out, run a tap through the holes and then put new screws in? To add to this I just broke a screw trying to loosen a tool.