sentences:  Also common are "pan head" screws - a low disk with a chamfered outer edge.Because they are used in places where high torque is not required and easy removal and replacement may be desirable (such as on the side panels of the PC case), they are frequently available as thumbscrews with larger, knurled heads that can be removed with one's fingers or tools.The M3 is a metric screw specifying a nominal diameter of ; and standard coarse thread pitch defined as .