This easy to read gauge is made from tough ABS plastic and allows the user to quickly measure the size of nuts, bolts, and screws.
Can also be used to determine whether a nut is UNC or UNF, taking the trial and error away from selecting the correct replacement size.
Measurements include: internal diameter of UNC & UNF nuts; diameter of metric & imperial bolts; length of rounded, pan, countersunk, set screws, together with hex head bolts; reference chart for hex cap screws