screw-jack

A mechanic uses a screw-jack to lift the side of a car.

Definition

1. Noun:
   • A mechanical device: A "screw-jack" is a type of jack that uses a screw mechanism to lift heavy objects, such as vehicles, by turning a handle that raises a threaded rod or platform.
   • A lifting tool: In engineering and automotive contexts, a "screw-jack" refers specifically to a portable device that applies mechanical advantage through a screw thread to elevate loads.

Usage Examples

• Noun:
  • The mechanic used a screw-jack to lift the car and change the tire. (A lifting device with a screw mechanism.)
  • A screw-jack is often employed in construction to raise beams or heavy equipment. (A tool for lifting heavy objects.)
  • The old screw-jack required significant effort to turn, but it was reliable. (A manual jack with a threaded rod.)

Advanced Usage

• "to operate a screw-jack": to use the device by rotating its handle.

  • He carefully operated the screw-jack to avoid damaging the vehicle's frame. (He turned the handle to lift the car.)

• "screw-jack mechanism": the internal screw-and-nut system that provides lifting force.

  • The screw-jack mechanism is simple but effective for vertical lifting. (The threaded system inside the jack.)

Variants and Related Words

• Screw jack (n): an alternative spelling of "screw-jack," often written without the hyphen.

  • A screw jack is a common tool in many garages. (Same device, different spelling.)

• Jack screw (n): a related term where the screw is the primary component, sometimes used interchangeably.

  • He adjusted the jack screw to level the machine. (A screw used in a jack-like device.)

Synonyms

• Lifting jack: a general term for any device that raises heavy loads.

  • The lifting jack was too small for the truck. (A broader category including screw-jacks.)

• Car jack: a common name for a screw-jack used in automotive contexts.

  • She stored a car jack in the trunk for emergencies. (A specific type of screw-jack.)

Related Idioms

• "To jack something up": a phrasal verb meaning to lift or raise something, often using a jack, but also used figuratively (e.g., to increase prices).

  • He jacked up the car with a screw-jack. (He lifted the car using the device.)
  • The company jacked up the prices after the holiday. (Figurative: increased sharply.)

• "Screw-jack lift": a specific type of lift performed by the device.

  • The screw-jack lift was steady and controlled. (The action of raising with the jack.)