Hi-Lok® Pin Protrusion Gauges from MRO Tools are manufactured for use on all types of frangible and torque-control fasteners. These gauges determine if the correct length pin has been installed by determining if the pins projection is between allowable minimum and maximum ranges shown on the gauge.Gauges are available for Hi-Lok®, Hi-Lite®, and Hi-Tigue® systems. To select the correct gauge for the fastener, select the one that corresponds to the appropriate pin diameter. If the pin falls short of the minimum limit or exceeds the maximum, it must be removed, and a more appropriate size selected. Exceeding the maximum limit requires a shorter pin, and falling short the minimum limit requires a longer pin. The correct pin will lie between the maximum and minimum limitations giving a proper ratio of grip to protrusion. These are complete sets that include gauges for -5 to -12 fasteners.