precision fitting work in the fabrication, adjustment, and repair of nonstandard measuring and metalwork-ing tools and complicated equipment for machine-building enterprises. Gauging tools include simple and complex gauges, profile templates, master devices for automatic machine tools (cams and guide blocks), dies, stamps, and standards—all of which are distinguished by high accuracy and smooth working surfaces.
Gauging tools are produced on an individual or sometimes small-series basis. Most of them are made on precision machine tools (lathes, milling machines, and grinders) equipped with accurate mechanical and optical measuring devices. Final finishing and lapping of some of the most complicated items, as well as restoration and readjustment of a precision tool that has been in service, is generally done by hand. Whetstones and laps are usually used in manual finishing; they provide dimensional accuracy to 2–3 microns and surface roughness of the tenth to 14th grade (Soviet standard). To check the accuracy of the shape, dimensions, and relative location of the working surfaces during the lapping of gauging tools, measuring instruments of ordinary accuracy are supplemented by checking the clearance of the items and by the “color,” or spot, method. Gauging tools are made from high-carbon tool steels and alloy steels with Rockwell C hardness of 56–64. Gauge work is performed in instrument shops of machine-building plants.
REFERENCEZagretskii, P. P., and K. S. Kharchenko. Slesar’-lekal’shchik, 2nd ed. Moscow-Leningrad, 1959.
I. G. GERTSKIS