Two of my three heatsinks have problems with the mounting holes for mounting them to the board. I can push the screws straight thru the hole. All this started when I tried to mount the Whioheatsink and I could not get the screw to grab the thread. While checking the holes for a thread issue I accidently pushed the screw all the way thru. Tried the other hole and same thing. Got the 2nd heat sink out and same problem. Tired the 3rd heatsink and all is well. Must be time for a new machine shop. Tomorrow I will go to HD and see if I can find a longer screw and a nut that would fit, or maybe I can find the right size screw for the hole that is in the heatsinks. The hole is smaller than the holes for the triacs so that screw is to big.