Griffith Double-Acting Hydraulic/Mechanical Drilling Jar

Our double-acting hydraulic/mechanical drilling jar is a versatile jar for complex drilling applications that features a hydraulic upstroke and downstroke with a mechanical latch.

Similar to our standard hydraulic/mechanical jar (HMJ) in design and operation, the benefits of a hydraulic delay downstroke make the double-acting hydraulic/mechanical drilling jar (DAHMJ) more effective for directional, horizontal, and extended-reach drilling. Additionally, no bleed-through operation is required when tagging or picking up off the bottom, making the DAHMJ ideal for compressional placement in the drill string.


  • More effective jarring – Hydraulic delay in both upstroke and downstroke
  • Engineered for high-friction directional, horizontal, and extended-reach wells – Allows weight stacking before firing, even while horizontal
  • Continuous, consistent performance – Modified fluid shearing technology from the aerospace industry provides reliable firing
  • Improved safety on the rig floor – The internal mechanical latch prevents unexpected jarring when making connections or drilling and eliminates the need for an external safety collar
  • GriffithForce Double Acting Hydraulic Drilling Jar Tech Summary

Three-fourths view of Griffith Double-Acting Hydraulic-Mechanical Drilling Jar
Three-fourths forced view of Griffith Double-Acting Hydraulic-Mechanical Drilling Jar
Three-fourths forced view of Griffith Double-Acting Hydraulic-Mechanical Drilling Jar

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