RING TO 1 1/2 RG API

Threaded gauges for controlling conical inch threads with a profile angle of 60 degrees. GOST 6485-69 Working calibers (corks and rings) should be made of three types: RR - threaded working; R-SP - special threaded workers; RG - smooth workers. Working calibers must be made in two versions: 1 - single-stage, with a step in the main plane; 2 - three-stage, with ledges in the main plane and in the planes corresponding to the largest and smallest limiting sizes. Control plug gauges (counter-calibers) should be made of three types: К-Р - threaded counter-calibers for rings of type РР Р; K-SP - special threaded counter-calibers for R-SP type rings; KG - smooth gauges for rings of type RG.