Hydraulic Mechanical Double Acting Jar is the drilling tool applied for the release of stuck tools. In case of drill string stuck, the jar facilitates its release.

Hydraulic Mechanical Double Acting Jars are specially designed to deliver hydraulic delay when jarring in the up direction and mechanical release when jarring in the down direction. A latch mechanism prevents the jar from releasing accidentally during drilling and tripping operations. Jarring intensity is controlled by the amount of the drill string tension during the hydraulic delay.