C’ bore Coarse bore---This has a tolerance class of 7H for internal threads and 8g for external threads( S/ X" q( R5 T+ I0 X1 K0 `% q
SHCS Screw hole countersunk head ' Z: ^; f" B' y3 b5 w+ x¼ Major Dia. Of threads . inch& y8 N g% _, ~' ] e$ j& l# w3 t