screw-thread

A worker inspects the screw-thread on a metal bolt.

Definition

1. Noun:
   • A helical ridge on a screw or nut: A "screw-thread" refers to the continuous, spiral ridge (or groove) that winds around the surface of a screw, bolt, or nut. This ridge allows the screw to be turned and driven into a material or to fasten two objects together by engaging with a corresponding thread.

Usage Examples

• Noun:
  • The screw-thread on this bolt is worn out, so it won't hold the nut properly. (The helical ridge is damaged, preventing a secure fit.)
  • Machinists must carefully cut a precise screw-thread to ensure the parts fit together. (The spiral ridge is created with accuracy for mechanical assembly.)

Advanced Usage

• "to strip a screw-thread": to damage the helical ridge so that it no longer engages properly.

  • He applied too much force and stripped the screw-thread, making the screw useless. (The ridge became deformed, preventing proper fastening.)

• "screw-thread pitch": the distance between adjacent threads, which determines how tightly the screw fits.

  • The screw-thread pitch of this bolt is too coarse for the delicate mechanism. (The spacing between ridges is too large.)

Variants and Related Words

• Thread (n): the helical ridge itself, often used interchangeably with "screw-thread" in casual contexts.

  • The thread on this screw is fine and precise. (The helical ridge is thin and accurate.)

• Threaded (adj): having a helical ridge or screw-thread.

  • This threaded rod can be used to connect two metal plates. (The rod has a screw-thread along its length.)

Synonyms

• Helical ridge: a spiral-shaped protrusion or groove.
• Spiral groove: the winding channel or raised line on a screw.

Related Idioms

• "to have a screw loose": (informal) to be slightly eccentric or mentally unstable; not directly related to "screw-thread," but uses the word "screw" metaphorically.

  • He keeps talking to himself — I think he has a screw loose. (He is acting oddly.)

• "to turn the screw": to increase pressure or coercion; also metaphorical, not directly about the thread.

  • The boss turned the screw by demanding longer hours. (He increased the pressure on employees.)