Covers requirements for gauging members for plain plug gauges for GO and NO GO members in the size range above 120 up to and including 250 mm. These plain plug gauges may also be used to check the minor diameter of internal threads when made according to IS : 4218 ( Parts I to VI ) ' ISO metric screw threads '.
IS 6246-1980 history
1980IS 6246-1980 Specifications for normal plug gauge GO and NO GO measuring pieces (size range 120 to 250 mm)