AMLOK® Hydraulic Series RCH Rod Clamp Power-Off Rod Lock

Hydraulic RCH Rod Clamps

Hydraulic RCH AMLOK Rod Lock by Advanced Machine & Engineering

Can Be Mounted to Any Machine Structure

  • Actuated by a spring/collet mechanism and unclamped by hydraulic pressure

  • Standard housing can be custom-designed to suit your application

  • Double-Acting



AMLOK® Hydraulic Series

The AMLOK Hydraulic Series RCH Rod Clamp has been developed to provide power-off clamping of rods and shafts. The type RCH Rod Clamps are actuated by a spring/collet mechanism and unclamped by hydraulic pressure. These rod clamps are designed to clamp components after the motion has stopped and to hold the position securely as long as the forces do not exceed the table values. For braking applications, contact us.
The mountings of the RCH AMLOK Rod Clamp have been designed to apply to standard heavy duty NFPA-style MF1 cylinders. The standard housing can be mounted to any machine structure or be custom-designed to suit your application.


The AMLOK Rod Clamp consists of an alloy steel housing containing a special locking mechanism actuated by a set of disc springs. The clamp is unlocked when hydraulic pressure actuates a piston that compresses the disc springs, and releases the locking device. Since the locking of the AMLOK Rod Clamp is accomplished mechanically and unlocked by hydraulic pressure, loss of hydraulic pressure to the rod clamp will cause the unit to lock.

The holding force depends upon the rod diameter and the amount of hydraulic pressure (PSI) available for unclamping. The AMLOK is preset at the factory to release at the specified hydraulic pressure. The available holding forces are listed in the chart and can be multiplied by adding additional AMLOK clamps to the same rod. Also, special SITEMA Safety Catchers and Locking Units can be provided to suit your needs.

How it works graphic

          Hydraulic pressure off - zero back pressure

Hydraulic pressure at minimum
release pressure not to exceed 3000 psi



Application Guidelines

When attached to cylinders, longer cylinder rods must be specified. The AMLOK Rod Clamp requires a full rod diameter for the entire length "L" of the clamp. Add a minimum of "L" length for a Rod Extension to allow for the length of the AMLOK.
Recommended rod tolerances are cited in the Catalog. Shafts consisting of commercial hard-chrome plated, polished rods are recommended. If the shaft has to support extreme stresses, e.g. in case of frequent switching operations, braking out of the movement, releasing under load or exposure to dirt, a hardened surface is necessary. If only securing the shaft (without relative movement in clamped condition) is required, an ordinary steel shaft will be sufficient.
The contact surfaces and bores to which the AMLOK is clamped must be square and concentric to each other to avoid binding of the rod or excess wear. AMLOK Rod Clamps can be an integral part of your housing. We can provide mating components for your special applications. 
The AMLOK is designed for zero side loads. When side loads are acting on the cylinder rod, make sure that the rod is guided sufficiently in bearings to avoid side loads on the locking mechanism. This is especially important at higher cylinder rod speeds to avoid overheating the clamping device due to excessive friction with the rod.
AMLOK Rod Clamps type RCH have provisions to mount one proximity switch to indicate "unlocked" condition. Please see Chart B for specifications.
Each AMLOK Rod Clamp is tested by Advanced Machine. These test results are available upon request. 
When properly applied, the Amlok RCH units are warranted for a period of one (1) year from date of shipment or one (1) million cycles, whichever comes first, to be free from defects of materials and workmanship.

Actuation & Circuit Recommendations

In most applications, the circuit suggested in the drawing is used. During every operational cycle, the 3-way valve is actuated electrically and releases the locking unit. In power failure, emergency stop, etc. the locking unit secures the rod and holds the load. In case the pressure fails, the load is secured in the same way.

To avoid possible problems, the shaft should not be moved unless the proximity switch indicates unclamped.

If pressure (p) is not sufficiently constant (e.g. pressure drop when lowering movement begins), we recommend installing a check valve in the p port as shown in the diagram.
Pressure spikes above rated pressure can sometimes be reduced by a snubber orifice upstream of the check valve.

To assure no air is trapped in hydraulic chamber, installation of the SIT-EMMEA-4 Air Bleed must be installed as shown in sample circuit.


Click image to enlarge

CAD Models

Order Instructions (click to enlarge)

For head rectangular flange mount (NFPA MF1 or MF5)


AMLOK - Oil Volume

Weight (lbs)

Part Number

Click Part # for CAD

volume to cycle
cm3 in3
6 0.4 11.5
6 0.4 10.5
16 1.0 20.8
16 1.0 31.0
10 0.6 20.0
16 1.0 30.2
30 1.8 66.0
30 1.8 65.1
39 2.4 75.5
30 1.8 65.1
39 2.4 114.0
129 7.9 270.0
145 8.8 380.0
181 11.0 550.0
230 14.0 530.0

Repair Service

AMLOKS, both pneumatic and hydraulic are rebuildable

AME offers an extensive repair service for AMLOK rod locks.
Please call for a return material authorization (RMA) number.

AMOLK Cutaway
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AMLOK RCH Rod Locks Catalog

 AMLOK RCH-Series Rod Locks 

PDF Catalog 1MB

Updated 05/2012


Price, Delivery & Technical Questions

Call 815 316 5226
Fax: 815 962 6483

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Trevor O'Malley
Product Manager

Becky Weed
Customer Service


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Advanced Machine and Engineering