Rod Locking Device - BEAR-LOC®

hydraulic cylinder rod lock
Bear-Loc Logo Final_RevA_Pantone 302
Hydraulic Rod Lock
hydraulic rod lock

If you're looking for a safe, reliable locking feature for your hydraulic components, look no further than Bear-Loc®. These innovative rod 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 and engineering expertise and the machining and manufacturing capabilities to produce a hydraulic locking device that meets your exact specifications.


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Examples of Bear-Loc® Hydraulic Lock 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.

Hydro control
Electric Generation & Hydro-Control
dam schematics hydraulic rod lock

Hydro-power generation gate locks for infinite position locking.

Dam Crest gate hydraulic rod lock

No-Slip Locks on Water Control Gates to ensure safety from flooding.

lift bridge
Civil Engineering & Construction Projects
Draw bridge hydraulic rod lock

Proper hydraulic system locking is essential in movable bridges, canal locks and water-related lifts.

material handling hydraulic rod lock

Locks conveyors and chutes in position with power off.

air craft carrier launch system
Defense, Security & Aerospace
missile launcher hydraulic rod lock

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

inspection vehicle hydraulic rod lock

Inspection vehicles assure that vehicles seeking to gain entry do not contain dangerous or unlawful cargo.

portal cranes
Construction Equipment
crane hydraulic rod lock

LIft Cylinder and Stabilizer Cylinder stability and Safety.

aerial lift hydraulic rod lock

When system safety is critical use Bear-Loc®.

parts press
Manufacturing & Testing Equipment
hydraulic press hydraulic rod lock

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

die casting machine hydraulic rod lock

The hydraulics system can experience high mechanical shock from acceleration.

oil rig
Natural Resources Extraction & Processing
oil rig hydraulic rod lock

Security locking device suitable for long-term heavy-duty, heavy-load offshore applications.

coal crusher hydraulic rod lock

Security locking device suitable for the harsh conditions and high frequency vibration in corrosive atmosphere.

Bear-Loc® Features Are Unparalleled

The abundance of advanced features sets Bear-Loc® apart from other hydraulic cylinder, air cylinder, pneumatic cylinder, and compressed air system 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. As a custom solution, it offers excellent Return on Investment (ROI) because it's built to last — expect decades of reliable service from your Bear-Loc®. For more information, keep reading or Inquire about Bear-Loc® now.

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 and bidirectional 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 2.75 inches to seven feet

lock capacities to 4 million pounds

The Purpose of Hydraulic Locking Systems

Hydraulic locking systems form an integral part of the safety and performance of critical systems by preventing dropped loads and unintentional moves.


Traditional locking systems work with received power and have an emergency stopping function that engages when power is lost. Their circuits include control valves and load-holding valves as the foundation of their safety support. Yet, valves alone may not reduce the chances of property damage and personal injury — they function best as the backup to a primary fail-safe solution like the Bear-Loc® hydraulic locking cylinder.

Bear-Loc® uses a positive locking approach to engage automatically the instant that power is lost. Unlike conventional systems, Bear-Loc® serves as a primary and reliable hydraulic locking fail-safe.


Off-the-shelf traditional locking systems have some restrictions, such as lower cylinder pressure limiting the load capacity and ability to handle higher-demand applications. 

In contrast, Bear-Loc® uses a patented design featuring an interference fit that can engage at any point along the rod and stroke phase when power ceases. Once power resumes, the Bear-Loc® disengages to permit movement again. Fewer contact points and components create lasting durability when used according to manufacturer instructions. Plus, Bear-Loc® can handle loads up to 4 million pounds, operating pressure ranges up to 5,000 psi and rods up to 27 inches in diameter.

Commonly Asked Questions | Bear-Loc®

Associations & Partnerships

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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 and Bidirectional 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.  The lock can be unlocked and instantly stroke either direction.

Available Configurations

 Choose the configuration that's best suited for your applications. Available as a cylinder lock combination or just a lock. Locking Actuators, Piston Rod Locks, Mill Type, Tie Rod Lock Construction, and rotary style. Customized for any application with up to 4 million pounds load holding capacity.

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.

Special Conditions

Special coatings and materials such as stainless steel can further enhance marine and subsea applications.

How Does a Hydraulic Lock Valve Work?

Inside every hydraulic and pneumatic circuit, there lie control valves and load-holding valves. Their purposes are to maintain an applied load or control load motion. 

Control valves align secondary-circuit pressure with spring-generated force to open. Pressure changes cause the control valve to open as pressure drops to help maintain consistent force. Common configurations for load-holding valves include single-acting and double-acting. In a single-acting design, the valves prevent movement in one direction only, while a double-acting style stops movement bidirectionally. 

Locking valves engage to limit drifting that can occur if the equipment is worn, faulty or in a neutral position, enhancing safety and preventing property damage. Design can vary and include automated locks, manual locks or a combination of both. 

The ideal lock style depends upon the operating environment and the following factors:

  • Operational pressure required
  • Desired locking location — for example, at any stroke point or only a fixed one
  • Appropriate level of automation
  • Spatial area and power needed for operation

Modern locking systems include a loaded spring or second cylinder as a supplement to the main actuator's rod cap, wherein the lock engages around the rod and holds it securely in place to prevent movement.

Bear-Loc® Operating Principle | How Does Bear-Loc® Work?

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 lock to stroke 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, rod-clamping occurs instantly and the Bear-Loc® offers totally easy failsafe operation.

Bear-Loc® Details

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 Temperatures
  • 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.

rod lock specifications

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 across North America, South America, and other parts of the world. Our Sales/Engineering Department is happy to assist you with additional information and discuss your special applications.

Read More

We Customize Our Patented Bear-Loc® to Meet Your Locking Needs From Small to Large.

rod lock

Bear-Loc® cylinder and lock combinations.

Hydraulic Rod Lock

Bear-Loc® provided for your hydraulic cylinder or stand-alone locking applications.

rod lock device

Bear-Loc® for off-shore platform, 610 tons of locking power.

cylinder rod lock

Custom or standard sizes, mill or tie-rod lock designs.

hydraulic locking cylinder

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

Crane with hydraulic lock

Bear-Loc® actuator for construction and vehicle-mounted hydraulic equipment

hydraulic rod lock on Forklift

Bear-Loc® for material handling hydraulic equipment

crest gate hydraulic lock

Bear-Loc® for Dam and water control system hydraulics

Awards & Certifications

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ITAR Registered #M39417
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Outstanding Performance
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SIBC Member
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NFPA Member
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Made In USA