ORFS fitting end is o-ring face seal tube fittings adapter end, it is according ISO 8434-3 SAE J1453 dimensions.
Tube O.D. T T Size inch mm UN/UNF Major thread ∅ mm ∅ D3 mm
4 1/4 6 9/16-18 14.0 5.0
6 5/16. 3/8 8, 10 1 1/16-16 17.0 6.5
8 1/2 12 1 3/16-16 20.5 9.5
10 5/8 14, 15, 16 1-14 25.0 12.5
12 3/4 18, 20 1 3/16-12 30.0 15.5
16 7/8. 1 22, 25 1 7/16-12 36.0 20.5
20 1 1/4 28, 30. 32 1 11/16-12 42.5 26.0
24 1 1/2 35, 38 2-12 50.5 32.0
32 2 50 2 1/2-12 63.0 45.0
All dimensions shown are nominal for identification only.
Small deviations may be found between SAE J1453 or ISO 8484-3 on bore sizes.