A work support comprises a plunger, a transmission member, a first chamber, a second chamber, a third chamber, a clamping mechanism, a plug, and a body. The plunger may be slidably retained within the clamping mechanism, which in turn is firmly held within the transmission member. The transmission member may extend and retract from the body corresponding to a pressure in the first chamber and the second chamber. Extension of the transmission member also extends the plunger such that the plunger may contact and receive a load from a work piece. The third chamber may be located between the outer surface of the clamping mechanism and the inner surface of the transmission member. Increasing pressure in the first chamber while decreasing pressure in the second chamber extends the transmission member and opens the plug which blocks the entry to the third chamber. Pressure in the third chamber closes the gap between the clamping mechanism and the plunger and applies a clamping force to the plunger.