If anyone is looking at buying screws for fixing cement board then avoid the offerings from Timco. This has surprised me as I have used Timco Velocity wood screws for some time but these screw for cement board to wood and cement board to metal stud both suffer from very bad cam out. They supply a bit with the screws which is useless and I then tried a wide range of bits to see if any work but they all just cam out and don't recess the screw.