Patent attributes
A compression gauge for measuring the compression applied to a test bolt. The compression gauge includes a passive hydraulic cylinder and a piston slidably disposed within the cylinder. The piston and the cylinder define an hydraulic chamber. A threaded test bolt passes through the piston and cylinder to engage a female receiver on the opposite side of the compression gauge. Tightening the test bolt will cause the bolt to compress the piston and cylinder which will pressurize the hydraulic chamber. A pressure gauge measures the pressure achieved in the hydraulic chamber. This pressure can be easily converted to compressive force. When a hydraulic wrench is used to tighten the test bolt, the wrench can be set to apply the same amount of torque to a workpiece bolt and thus apply the desired amount of compression to the workpiece bolt.