Had to install deadbolt lock on door. I've read reviews that said it's mostly only good for light jobs. I thought I'd try anyway. I was amazed at how easily he drilled a hole in the door. He stopped drilling the hole halfway through because the door was so thick. I broke off a piece inside the hole, finished the hole and installed the lock. I really had no problems. Only thing I can say is make sure you have a good powerful drill bit when using this and you shouldn't have any trouble drilling holes in wood.