ARP's Rod Bolt Stretch Gauges are highly recommend for when installing rod bolts and other fasteners, where it is possible to measure the length of the bolt after tightening. These gauges offer the most accurate way to determine the correct pre-load in the rod bolt. These highly accurate stretch gauges come with a dial indicator that reads in increments of .0005''. Featured are extra heavy springs for consistent repetition and includes a heavy-duty, insulated plastic carrying case for protection.
Instructions: Measure the fastener prior to starting, and monitor overall length during installation. When the bolt has stretched the specified amount, the correct preload, or torque has been applied. It is recommended that you maintain a chart of all rod bolts, and copy down the length of the fastener prior to and after installation. If there is a permanent increase of .001'' in length or more, or if there is deformation, the bolt should be replaced immediately.