B 1.4841 Bore clamp 

The bore clamp is particularly suited for clamping of workpieces with smooth bore holes from diameter 7.8 to 17.7 mm in the support surface.

The bore clamp is a double-acting pull-type cylinder. An exchangeable clamping bushing is fixed to the piston.
The 4 segments of the clamping bushing are radially expanded with spring force by a conic clamping bolt. Thus the expansion force is always the same and independent of the hydraulic clamping pressure. Both unclamping of the clamping bushing and pull-down clamping of the workpiece are controlled hydraulically.
Connecting the positive air pressure protection, the clamping bushing is protected against swarf and coolants. In the hardened support surface for the workpiece there is a bore hole for connection of a pneumatic seat check.