6403-O Steel Male ORB x Male ORB Union Check Part Number TUBE OD B (1) UN/UNF-2A B (2) UN/UNF-2A L34 C4 D (1) D (2) 6403-06-04-O 3/8-1/4 9/16-18 7/16-20 1.11 0.69 0.30 0.17 6403-08-08-O 1/2-1/2 3/4-16 3/4-16 1.26 0.88 0.39 0.39 6403-10-08-O 5/8-1/2 7/8-14 3/4-16 1.38 1.00 0.48 0.39 6403-10-10-O 5/8-5/8 7/8-14 7/8-14 1.44 1.00 0.48 0.48 6403-16-12-O 1-3/4 1 5/16-12 1 1/16-12 1.72 1.50 0.84 0.61