Definition

1. Noun:
   • A mechanical lifting device that uses a screw mechanism to raise or lower heavy loads: A "screw jack" is a type of jack where a screw thread is the central component. Turning the screw with a lever or handle converts rotational force into linear motion, allowing for precise, controlled lifting or lowering.

Usage Examples

• Noun:
  • The mechanic used a screw jack to lift the car's axle safely.
  • For stability on uneven ground, a screw jack is often preferred over a hydraulic jack.

Advanced Usage

• "to operate a screw jack": to use a screw jack by turning its handle or lever.
  • You must operate the screw jack slowly and steadily to avoid sudden shifts.

Variants and Related Words

• Jack (n): A general device for lifting heavy objects.
  • He carried a jack in his car for emergencies.
• Screw (n): A cylindrical rod with a helical ridge (thread) used as a fastener or in mechanisms.
  • Turn the screw clockwise to tighten it.

Synonyms

• Mechanical jack: A jack that operates through mechanical means (like gears or screws) rather than hydraulic fluid.
• Lifting screw: A term emphasizing the screw component used for lifting.

Related Phrases

• "to jack something up": to raise something using a jack.
  • We need to jack up the beam before we can place the support.

Noun

1. screw-operated jack