They're precision instruments that utilize smaller screws on pocket watches and eyeglasses. It is actually generally known as a check out or eyeglass driver. They are generally Philips and flathead screwdrivers. The head of your screw may be the area where by it'll end exterior the area within your challenge/material. https://types-of-roof-material48260.blogrelation.com/35406210/different-types-of-screw-heads-an-overview