AMBUSH Squeeze Bushings Clamp Moving Shafts to Fixed Housings

AMBUSH Squeeze Bushings


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AMBUSH Squeeze Bushings

Can Be Used With Any High Pressure Hydraulic Fluid

  • Clamp moving shafts to fixed housings

  • Designed to resist axial (ASA) and torsional (AST) forces

  • Pressure up to 5000 PSI



Made of High Quality Alloy Bronze or Spring Steel

AMBUSH® Hydraulic Squeeze Bushings are used to clamp moving shafts to fixed housings in a wide range of applications.

Type ASA Squeeze Bushings are designed to resist axial forces only. They are commonly used in fixturing and reciprocating shaft applications.

Type AST Squeeze Bushings are designed to resist torque as well as axial forces. One or two holes (for dowel or roll pins) have been provided in the mounting cap to resist the torque and to insure that the Squeeze Bushing does not move.


Each AMBUSH is made of high quality alloy bronze with a special plastic, molded over the slotted squeeze surface. Seals are provided at each end to resist hydraulic pressure up to 5,000 psi (340 bar) depending on diameter. For higher pressure (up to 10,000 psi) contact our engineering department.

The ASB Bearing is made of 660 bronze.

Hydraulic pressure acts upon the molded sleeve (between the seals). The hydraulic pressure compresses the bushing radially over the entire length between the seals. This squeeze action locks the shaft to the bushing with high efficiency without introducing any movement to the shaft. Very accurate clamping can be accomplished in many fixture, machine tool and general applications. 



Tolerances and Material of Mating Parts

Housing bore diameter ISO H7 with surface finish in seal area 32 micro inches. Ferrous or non-ferrous materials can be used, but must have sufficient strength to resist the hydraulic pressure.

Shaft diameters of ISO f6 require surface finish of 63 micro inches or better. Shaft materials can be ferrous or non-ferrous, soft or hard.

Note: Some surface treatments of the shaft may reduce the coefficient or friction and thus the holding force.

Squeeze Bushings by AME
Design Hints

Provide polished chamfer on the bore to permit assembly without pinching the "O" rings (see assembly instructions in catalog).

The housing wall should be thick enough to resist the same pressure that is used to clamp the squeeze bushing.

Provide for air bleeding at the highest point of the bushing's O.D. relief pocket and also the hydraulic lines.

To prevent axial movement under load, bushings must be preloaded. Preload must be 0.0002 to 0.0003 x length (inches). If preload is too high, bushing will not function properly!

Tapped holes are provided in the flanges for easy removal of the type AST Squeeze Bushing.

Be sure that lubrication oil is not trapped on the I.D. of the Squeeze Bushing which reduces clamping forces.

Locate oil inlet or bleed holes not closer than s+12mm (s+.50 in.) from each end. Oil inlet hole size about 4mm (.157 in.) diameter.

Provide shoulders on each end of the bushings to help support hydraulic and thrust forces. Maximum clearance is 0.25mm (.010 in.) for diameters and 0.1mm (.004 in.) for axial location.

Click To Enlarge

Squeeze Bushings are not designed to take heavy sideloads. For this reason, auxiliary bearings are offered for each size of Squeeze Bushing. The performance of a bearing is influenced by the conditions of speed, mating materials, clearance, temperature, lubrication, type of loading etc. Of primary importance is the maintenance of an oil film between the bearing surface to reduce friction, dissipate heat and retard wear by minimizing metal to metal contact. The most critical periods of operation are during starting and stopping. Recommended oil for moderate speeds is SAE20.



symbol description value unit value unit

axial holding force

lb N

I.D. of squeeze bushing

see table inch see table mm

length of squeeze bushing

see table inch see table mm

shoulder width of squeeze bushing

see table inch see table mm
p hyd

available hydraulic pressure

psi N/mm2

coefficient of friction; well lubricated





holding torque

in-lbs. Nm

(maximum) sideload

lb N
p surf

(maximum) surface pressure

3000 psi 20 N/mm2

safety factor

(3) * - (3)* -

revolutions of the rod

RPM 1/min

linear velocity of the rod (axial)

ft/s m/s

bearing factor

0.53 1/s 43.50 1/s

* recommendation

Conversion factors: 1N = 0.225 lbs 1 bar = 0.1 N/mm2 = 14.5 psi
  1Nm = 8.8583 in-lbs 25.4 mm = 1 in

Specs & CAD

Inch CAD Models



Metric CAD Models




AMBUSH Squeeze Bushings Catalog

AMBUSH Squeeze Bushings

> PDF Catalog 1.6MB




Price, Delivery & Technical Questions

Call 815-316-5252
Send an email 

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Shane Hatfield
Product Manager


Crystal Goellner
Customer Service



Advanced Machine and Engineering