I found another way to mount t-nuts. I 'set' them in the plywood by giving them a gentle tap with a hammer. This prevents them from falling out. I like Wayne's idea of adding a dab of glue to each fastener. Then, instead of drawing them down with a screw, I pressed them into place with a Pony clamp. Works like a charm and there is no added stress to the threads. When I was a kid I used this method to put pistons back into brake calipers.