Rod Locking Device - BEAR-LOC®

hydraulic locking device

If you're looking for a safe, reliable locking feature for your hydraulic components, look no further than Bear-Loc®. These innovative locking devices have earned the trust of companies around the world because of their innovative design, ease of use and — most of all — their safety. Bear-Loc® is the ideal solution whenever you need high system stiffness, zero backlash and infinite position locking.

York Precision Machining & Hydraulics is pleased to offer these state-of-the-art hydraulic locking actuators for sale to our current and future customers. We have the in-house design, engineering expertise and machining and manufacturing capabilities to produce a hydraulic locking device that meets your exact specifications.

small robotics actuator

Bear-Loc® for nuclear industry inspection robot

Our largest to date: refurbishing for a tug barge, <br>this Bear-Loc® boasts 4 million pounds of locking power.

Our largest to date: refurbishing for a tug barge, this
Bear-Loc® boasts 4 million pounds of locking power.

We customize our patented Bear-Loc® to meet your locking needs from small to large.

Bear-Loc® actuator for offshore oil platform: 610 tons of locking power.

Bear-Loc® actuator for offshore oil platform: 610 tons of locking power.

Bear-Loc® Details

BEAR-LOC® Features Are Unparalleled

The abundance of advanced features sets BEAR-LOC® apart from other hydraulic cylinder lockout devices on the market. Lockout capability is just one of its features. The wide range of available configurations make it extremely versatile — you can use it for many different applications. It's also built to last — expect decades of reliable service from your BEAR-LOC®.

BEAR-LOC® has a unique patented design based on the principle of elastic expansion of metal under pressure.

No other locking device combines

☑ fail-safe reliability

☑ infinite position locking

☑ zero backlash

☑ high system stiffness

☑ Easy to use

BEAR-LOC® has a unique patented design based on the principle of elastic expansion of metal under pressure.

BEAR-LOC® can be customized and comes in a wide range of sizes

 rod diameters from 1 inch to 27 inches

sleeve lengths from 1 inch to seven feet

lock capacities to 4 million pounds

Examples of use

BEAR-LOC®'s ultimate combination of reliability, versatility, safety and ease of use makes it the ideal hydraulic locking device for a multitude of industrial applications. Industries that can benefit from BEAR-LOC® include defense, construction, oil and gas, marine, manufacturing and mining. Check out a few of the many possible applications below.


Utilizes Rotary, Linear and Jacking Bear-Loc®'s.

material handling
Material Handling Equipment

Locks conveyors and chutes in position with power off.

oil rig
Drilling Rigs

Long term heavy duty, heavy load offshore applications.

hydraulic press

Platen adjustment requires infinite position mechanical locking under heavy load cycling on hydraulic presses.

missile launcher
Missile Launchers

Inherent locking system stiffness provides accuracy and stability as required in missile launchers.

aerial lift
Man Lifts

When system safety is critical use Bear-Loc®.

coal crusher
Coal Crushers

Suitable for the harsh conditions and high frequency vibration in corrosive atmosphere.

tug barge
Tug & Barge Connections

A unique Bear-Loc® application with 4,000,000lb lock capacity.

BEAR-LOC® Capabilities

Automatic Locking

BEAR-LOC® always locks automatically when sleeve pressure is relieved, whether its removed on command or lock pressure loss occurs. Locking action is positive. Movement is impossible when the BEAR-LOC is operated within its lock capacity. This vital safety feature helps to prevent on-the-job injuries.

Infinite-Position Locking

The cylinder rod can be engaged by the locking section of the sleeve at any position in the stroke. You'll have the flexibility to change the configuration quickly and with minimal effort.

Available Configurations

 Choose the configuration that's best suited for your applications. Available options include Lock Unit Only, Locking Actuators, Piston Locks, Mill Type and Tie Rod Construction.

Design Simplicity

BEAR-LOC®'s capability does not depend on adding moving parts, values or other components for its positive mechanical lock. Fewer moving parts means there are fewer things that can go wrong, as well as minimal preventive maintenance requirements.


BEAR-LOC® offers a wide range of configurations and mounting styles to meet almost any space envelope requirements. You can even use it in confined areas at your facility or job site.

BEAR-LOC® operating principle


The spareness of the design is a defining characteristic of this revolutionary hydraulic cylinder safety stop, with failsafe lockout as just one of its capabilities. Because the locking does not depend on moving parts to function, you'll enjoy the benefit of smooth, efficient operation, regardless of locking position or configuration. This operating principle is also what makes BEAR-LOC® so easy to use.

Here's a quick overview of how BEAR-LOC® works:

The BEAR-LOC® Section is comprised of a cylinder rod and liners enclosed in a sleeve which forms an interference fit with the outside diameter of the rod. This fit provides a positive mechanical connection to lock the rod in any phase of the stroke. As soon as hydraulic pressure is applied the sleeve expands radially within the elastic limits, relieving the interference and creating enough clearance for the rod to be stroked with minimal resistance.

Simply removing the hydraulic pressure via the unlock port allows the BEAR-LOC® to re-engage automatically. Thus even with accidental lock pressure loss, the BEAR-LOC® offers totally automated operation.

What to know when ordering

When you buy a hydraulic locking actuator or any other component from York Precision, you get a built-to-order product that will provide a custom solution for your manufacturing operation. We strive to make the customization process as hassle-free as possible. Just supply us with the information and specifications listed below, and we'll design, engineer and manufacture a product that will exceed your performance and quality expectations.

BEAR-LOC® units can be supplied in a wide variety of configurations for locking both liner and rotary motion.

  • Quantity required (number of units)
  • Cylinder bore, rod size (diameter)
  • Mounting style (e.g. trunnion, regular or heavy flange, tab mount, foot, or extended tie rod)
  • Unlock pressure or Operating Pressure (2000, 3000, 5000 psi)
  • Overall envelope length
  • Required locking capacity (weight)
  • Length of stroke
  • Operating Temperatues
  • Type of cushioning:
    • Non-cushioned
    • Cushioned rod end
    • Cushioned blind end
    • Cushioned both ends
  • Position of Ports
  • Any other special requirements or conditions for your application
  • What other locking mechanisms are you considering?

Also specify: Position of port (if other than shown), unusual operating conditions (such as high or low temperature), type of fluid, etc.

Engineering Questions

York Precision Machining & Hydraulics — Your Hydraulic Locking Manufacturer

When you purchase a hydraulic cylinder locking device like BEAR-LOC® from York Precision Machining & Hydraulics, you get the benefit of nearly half a century of hydraulics component manufacturing experience. Our roots run deep in design, engineering and machining, and we apply this expertise to every aspect of our customers' projects.

Give us a call today at 717-764-8855 to learn more about BEAR-LOC® and how it can add value to your industrial applications. We'll also be happy to provide a no-obligation quote.

BEAR-LOC® units can be supplied in a wide variety of configurations. Our Sales/Engineering Department is happy to assist you with additional information and discuss your special applications.

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Outstanding Performance
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Combat Proven
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Excellence Presented By Commander

Last Updated: May 13th, 2020