ULTIMATE Double-Acting Hydraulic Drilling Jar
ULTIMATE Double-Acting Hydraulic Drilling Jar
UHJDA
ULTIMATE Double-Acting Hydraulic Jar
The advantage of the ULTIMATE Double-Acting Hydraulic drilling jar (UHJDA) is its ability to dramatically increase the allowable overpull force during detent. Our patented “Max Pull During Delay” feature is designed to take advantage of higher tensile forces available on modern rigs and with premium strength drill pipe that is currently used in industry. The proprietary ULTIMATE design can handle significantly higher overpull forces during delay than any other jar in the market.
The UHJDA is a bidirectional drilling jar that incorporates hydraulic delay without a latch mechanism. This allows the operator to apply variable impact in both the up and down directions in highly deviated or high-friction wells where conditions may prevent applying sufficient force to release a mechanical latch.

Feature overview
- Hydraulically controlled by an internal metering device
- Ensures consistent delay over the full range of operating temperatures
- Impact force controlled by operator
- Jars in both directions
- Operates via up and down motion
- Unaffected by right- and left-hand torque
- Standard seals are suitable for use up to 250ºF (120ºC); optional high temperature seal kits are available for service to 400ºF (200ºC)
- External sealing surfaces are tungsten-carbide coated to enhance wear and corrosion resistance
Operation
When jarring up:
- With the jar in neutral position, apply the desired overpull in excess of the free string weight, which will start the hydraulic delay sequence. At the end of the hydraulic delay, the jar will release, causing an upward impact force.
- If necessary, lower the drill string sufficiently to close the jar to the neutral position and it will be ready to jar up again.
When jarring down:
- With the jar in the neutral position, lower the drill string to apply the desired down force, which will start the hydraulic delay sequence. At the end of the hydraulic delay, the jar will release, causing a downward impact force.
- If necessary, raise the drill string sufficiently to open the jar to the neutral position and it will be ready to jar down again.
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Contact Us
Questions about our products or services? We are here to help.
Fill out the form below to contact our team by email. We will get back to you as soon as possible.




