You NEED this Handy Bit Driver for hard to get to screws! Designed with tight tolerances. Its easy to fit any standard ¼ bit. Scale up 1% if you don't like how tight it is. I've tried milwuakee, makita, dewalt, and generic all types of bits all fit fine. Designed with 100% infill I have yet a screw to find that could break this. Enjoy!