screw thread

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The continuous helical groove on a screw or on the inner surface of a nut.
• noun One complete turn of a screw thread.

from The Century Dictionary.

• noun The spiral ridge formed on the cylinder of a male screw, or on the inner surface of a female screw or nut.
• noun A single turn of the spiral ridge of a male or female screw: used by mechanics to designate the number of such turns in a unit of length of the axis of the screw. Commonly called simply thread.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun engineering A helical ridge which wraps around an elongated cylindre, or a groove spiraling around the wall of a bore, used to convert a rotational movement into a linear one.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the raised helical rib going around a screw