Specification :

Hydraulic Drilling Jar is an integral hydraulic jar with up jarring and down jarring. When downhole drilling tools are stuck, the jar can provide a huge impact to unfreeze with up jarring or down jarring, thus normal drilling operation can be recovered quickly.
When the jar is used, operators can adjust to picking up it or slacking off it on surface to create up jarring impact or down jarring impact (without addition to the torque or adjustment to the outside part) and adjust impact from very small range to the biggest range needed. The jar can be operated easily and conveniently with high reliability and applied to many downhole activities of drilling, coring, fishing, workover, etc.