Special Bore Gage Measuring Heads We offer several configurations of special purpose measuring heads for 780, and 781 Bore Gages, available by special order. Some, but not all, of these will also work with the 78 Bore Gages. Groove Measuring Heads • Groove. Available as a 2-point system for ovality measurement. • Various2-pointanvilformsavailablewithdiametersfrom.080-12"(2-300mm). • Grooves. Available as a 3-point system • Various3-pointanvilformsavailablefordiametersfrom.250-12"(6-300mm). Thread Measuring Heads Thread Measuring Heads are available as two point system from 8 to 5/16" (M4-8mm) and three point system from 3/8"-12" (9.5-300mm). Most forms available including UNC, UNF, UNJ, UNS, Buttress,Acme, Multi-start, LH and RH. • Thread. Thread forms available as a 3-point system. • Internal. To measure effective (functional) diameter, pitch diameter. • Available as two point system from 8 to 5/16" (M4-8mm) Available as three point system from 3/8"-12" (9.5-300mm). • Most forms available including UNC, UNF, UNJ, UNS, Buttress, Acme, Multi-start, LH and RH. Spherical Radius Measuring Heads • Spherical Radius. Available as 2-point to measure ovality or with 3-point contact. • Available with diameters from .236-3.93" (6-100mm). • 3-Point Spherical. Available in .118-12" (3-300mm) range. • Gives good repeatability even when somewhat out of line with bore center. 212 B ore G ages