Surface Roughness Specimens: This set of Surface Roughness Specimens is for inspecting, identifying and determining the roughness of machine parts; featuring 30 different specimens for surface grinding, reaming, grinding, turning, horizontal and vertical milling. Size: Surface roughness specimens have AA grade values displayed in inches and microns with an accuracy within ±12% of nominal; all 30 specimens are made of electroformed solid nickel and measure 0.05 x 12.5mm. Easy Comparison: each type of surface finish is accurately and consistently reproduced, giving the operator a realistic idea of the feel, appearance and texture of the machined part; comparisons can be made with a magnifying glass or using a scratch test. Cost-Saving Inspection: eliminates the need for expensive inspection methods, saving time and reducing scrap due to poor surface quality. Set Includes: Roughness Specimen Kit includes a vinyl wallet and instructions., Manufacturer: KOGEDSS