M6 75MM on the Top, M5 50 MM on the bottom. Home Depot has them in the specialty slide out drawers at all locations, unless they are out. I also keep every extra screw from every bracket we install. I was able to use three of the black spacers from Peerless brackets and three washers to make the top of the bracket even with the bottom. I agree, stupid design. It's really not a bad entry level TV, but the mounting is crap. And yes, the top bolts are a different size than the bottom....thanks Sony.