You need to get M8 screws. I had the same problem and called Samsung. They told me to get M4 but they were wrong as I bought them and they were too small. I found in the TV manual it requires M8 screws. These are metric so be sure to get that kind. When you install them they may not fit through your mount holes. My son had to drill mine a little larger. Also you need to use the black round spacers that came with the TV as the screws don't screw in all the way. I realized this after finally getting it mounted and couldn't figure out why the screws were sticking out. I hope this helps. It was a hassle to get this TV mounted but I am very pleased with the TV itself.