Detachable : The required thread gauge can be easily removed , and nuts or bolts can be screwed into the thread gauge to quickly identify thread sizes . When performing thread inspection in tight areas or visiting a hardware store for missing bolts or nuts , it is more convenient and faster than manual measurement of dimensional inspection Product Construction : Our nut and bolt thread gauge kit is made of aluminum alloy . Each thread detector has a red or blue oxide layer and uses engraving technology to make it wear resistant , legible , and easy to read . For many professionals or DIY enthusiasts , this set of nuts and thread gauges is a must have tool and present Function : The bolt and nut detection gauge has 50 male/female threads , which can not only help you solve the bolt and nut problems encountered in daily mechanical work or household projects , but also quickly help you sort out the mixed bolts and nuts , and there is a tool box to store to avoid loss Set Contents : 50 piece set of nut and bolt thread detectors in 27 imperial and 23 metric , each thread detector inserted into a black storage case with foam storage rack 3 Methods : There are three ways to read the size , the engraved size on the thread gauge , the printed size on the label and the screen printing size on the foam . Each size printed on the label chart and foam corresponds to the thread gauge size , allowing for a clearer and more visual view of the dimensions and removal of the corresponding gauge when a thread inspection is required, Manufacturer: Sutowe