ARP Rod Bolt Stretch Gauge 100-9942

We highly recommend using a stretch gauge when installing rod bolts and other fasteners, where it is possible to measure the length of the fastener. It is the most accurate way of measuring preload of any bolt. Simply follow manufacturer's instructions. When using a stretch gauge it's best to measure the fastener prior to starting and monitor overall length during installation. When the bolt has stretched a specified amount, the correct preload or clamping force has been applied. We recommend that you maintain a chart of all rod bolts and make a note of the fastener length prior to installation and after any disassembly. If there is a permanent increase beyond the manufacturers recommendation, there is a deformation and the bolt should be replaced.