Double-sided smooth plug calibres with inserts with diameters from 3 to 50 mm

Smooth plug gauges are used for hole inspection. Structurally, they are made in the form of a handle and a working part. The working part can be made in one piece with the handle or in the form of inserts and nozzles. For plug gauges intended for inspection of precise holes (6-12th qualification), the inserts are made of hard alloy. Plug gauges can be single-sided or double-sided. Single-sided calibres are either through or non-passable. Smooth gauges allow controlling linear dimensions from 0.1 to 3150 mm. With increasing dimensions, the control error increases due to the growth of elastic deformations of the gauges. In smooth plug gauges, the pass side (PR) has the smallest limit dimension (i.e. must pass into the hole) and the non-pass side (NOT) has the largest limit dimension (i.e. must not pass into the hole).