A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread. A screw thread is defined as a ridge of uniform section in the form of a helix on either the external or internal surface of a cylinder. Internal threads refer to those on nuts and tapped holes, while external threads are those on bolts, studs, or screws. screw thread, thread - the raised helical rib going around a screw. setscrew - a screw (often without a head) that fits into the boss or hub of a wheel or cam etc. and prevents motion of the part relative to the shaft on which it is mounted.

A screw thread is defined as a ridge of uniform section in the form of a helix on either the external or internal surface of a cylinder. Internal threads refer to those on nuts and tapped holes, while external threads are those on bolts, studs, or screws. used herepressing unit between two fragments with the first half of the screw near the point threaded, with the diameter of the ridges greater than that of the unthreaded half near the head. The repair relies on the strength of the bone and its ability to grip the screw thread and so is less effective if the bone is weak.

Pitch, Screw-Thread the distance between parallel sides of the profiles of two adjacent thread forms measured along the axis. The pitch is usually measured along a line on which the width of the thread forms is equal to the width of the groove. Multiple threads have both a pitch and a lead;