A
jack is a mechanical device used a as a
lifting device to lift heavy loads or to apply great forces. A
mechanical jack employs a
screw thread for lifting heavy equipment. A
hydraulic jack uses
hydraulic power. The most common form is a
car jack,
floor jack or
garage jack, which lifts vehicles so that maintenance can be performed. Jacks are usually rated for a maximum lifting capacity (for example, 1.5
tons or 3 tons). Industrial jacks can be rated for many tons of load. अंकित