Ill check into them but I don't think mt threads are going to strip out. I rebuit the area's with some oak 2 laminations 1/4 x1/4 so there is a half inch. I used this oak on a weight tray for an 80inch span airplane and its a chore to thred them in. This time I will use a little wax on the threads to help in putting the screws in. But I will check out the inserts and see if I like them