This tool offers the most accurate measurement of pre-load in the rod bolt. Measure the fastener prior to starting, and monitor overall length during installation. When the bolt has stretched the specified amount, the correct preload (torque) has been applied. USRT recommends 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. Don't chance it!