TUBE OD UN / UNF S L L1 D2 PART NO. mm Inch N mm mm mm mm 6 1/4 7/16 -20 17 52.6 31.5 4.4 4F-UB 8 5/16 1/2 -20 19 52.6 31.5 6 5F-UB 10 3/8 9/16 -18 22 55.4 33.5 7.5 6F-UB 12 1/2 3/4 -16 24 62 37.6 9.9 8F-UB 14/15/16 5/8 7/8 -14 30 69.6 41.1 12.3 10F-UB 18/20 3/4 1 1/16 -12 36 78.5 45.4 15.5 12F-UB 25 1 1 5/16 -12 41 79.8 45.4 21.5 16F-UB 28/30/32 1 1/4 1 5/8 -12 50 84.1 46.7 27.5 20F-UB 35/38 1 1/2 1 7/8 -12 55 89.4 47 33 24F-UB