PG Conduit Thread PG Conduit Thread mm 80 3 12.50 PG 7 PG 7 1.27 external 6g 12.30 11.69 11.08 internal 6H 12.65 12.04 11.43 11.400 15.20 PG 9 PG 9 1.41 external 6g 15.00 14.33 13.66 internal 6H 15.35 14.68 14.01 14.000 18.60 PG 11 PG 11 1.41 external 6g 18.40 17.73 17.06 internal 6H 18.75 18.08 17.41 17.250 20.40 PG 13.5 PG 13.5 1.41 external 6g 20.20 19.53 18.86 internal 6H 20.55 19.88 19.21 19.000 22.50 PG 16 PG 16 1.41 external 6g 22.30 21.63 20.96 internal 6H 22.65 21.98 21.31 21.250 28.30 PG 21 PG 21 1.58 external 6g 28.00 27.24 26.48 internal 6H 28.55 27.79 27.03 26.750 37.00 PG 29 PG 29 1.58 external 6g 36.70 35.94 35.18 internal 6H 37.25 36.49 35.73 35.500 47.00 PG 36 PG 36 1.58 external 6g 46.70 45.94 45.18 internal 6H 47.25 46.49 45.73 45.500 54.00 PG 42 PG 42 1.58 external 6g 53.70 52.94 52.18 internal 6H 54.25 53.49 52.73 52.500 59.30 PG 48 PG 48 1.58 external 6g 59.00 58.24 57.48 internal 6H 59.55 58.79 58.03 57.750