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Bore clamp, hydraulic, eccentric

double acting,
max. operating pressure 250 bar,
min. operating pressure 40 bar.
Lateral compensation per clamp ± 0,25 mm.

Article no. Clamping force
Clamping rim height
min. for Al-alloy
dia. K
L Weight
323501 6970D-11-60 9,5 9 10,9 - 11,8 11 2000
323527 6970D-12-60 9,5 9 11,9 - 12,8 11 2000
323543 6970D-13-60 9,5 9 12,9 - 13,8 11 2000
323568 6970D-14-60 9,5 10 13,9 - 14,8 11 2100
323584 6970D-15-60 9,5 10 14,9 - 15,8 11 2100
323600 6970D-16-60 9,5 10 15,9 - 16,8 11 2100


The actuating piston is double-acting. Cylinder body, clamping segments and tensioning bolts are from hardened steel, gas-nitrided. Two-part clamping segments are externally serrated. A Ø 8 H7 centring hole located on the underside for positioning the clamping elements. Supply scope includes three fastening screws. Oil supply via oil channel in fixture body.


The hydraulic bore clamp is preferred for use on workpieces with complex external geometries that must be clamped for machining.
After the clamping segments engage into clamping holes attached on one side with low depth, reliable 5-sided machining does not present a problem.
Workpieces can be installed or removed automatically with handling devices.


Two clamping segments are spread in parallel, thus ensuring contact on the entire surface in every position of the tension bolt. This facilitates a high clamping power and ensures very low wear.
Elastic rings hold the clamping segments together and seal them against entry of chips. Depending on the material, the external serration is pressed into the clamping hole with more or less force, thus permitting the required positive fit. The built-in plate springs achieve a max. pull-down stroke of approx. 0.2 mm during clamping.

The integrated air connection is used for clamping control. The pull-down movement opens the passage of a compressed air hole, thereby creating a pressure drop of approx. 2 bar, which can be evaluated as a clamping control.

The holding bolts are sword-shaped for better pre-centring of the workpieces. The complete clamping-segment/holding-bolt unit can be turned so that an optimal force flow toward the workpiece centre can be set and locked. By setting the clamping elements, overloading of the clamping hole ( spreading force ) with low clamping rim is avoided.

The bore clamp is simultaneously the contact surface for the workpiece.
The workpiece contact surface is hard-metal coated (µ 0.3), which markedly increases the displacement force.

The eccentric arrangement of the clamping elements is especially suited for clamping workpieces with circumferential contact edge, such as gear and engine housings, oil pans and similar workpieces.


The lateral force when inserting the workpiece must not exceed the "lateral force" table value. The radial force must be observed.

Please check with us for clamping hardened workpieces or those from GG / GGG.

On request:

Bore clamps for other hole diameters available upon request.

On request, the integrated air connection can be used for cleaning the clamping area. The blow-off can also be used as a mount check for blind holes.

  • dimensions table
    Article no. Permissible
    horizontal force
    Radial force of
    sleeve segments
    of sleeve
    Clamping piston diameter
    Vol. Sp
    Vol. Lo
    Side load
    C dia. D
    Order No.
    323501 6970D-11-60 2,8 27 1,5 22 1,7 0,5 100 10,5 10,6 260448
    323527 6970D-12-60 2,8 27 1,5 22 1,7 0,5 110 10,5 11,6 260448
    323543 6970D-13-60 2,8 27 1,5 22 1,7 0,5 130 10,5 12,6 260448
    323568 6970D-14-60 2,8 27 1,5 22 1,7 0,5 160 10,5 13,6 260448
    323584 6970D-15-60 2,8 27 1,5 22 1,7 0,5 200 10,5 14,6 260448
    323600 6970D-16-60 2,8 27 1,5 22 1,7 0,5 250 10,5 15,6 260448