PART NO. THREAD OD TUBE DIMENSIONS IS F D1,D2 A B L S1 S2, S3 1Q-10 M10X1 M10X1 5 12.5 12.5 31 12 14 1Q-12 M12X1.5 M12X1.5 6 15.7 15.7 37.4 14 14 1Q-14 M14X1.5 M14X1.5 8 17 17 40 17 17 1Q-16 M16X1.5 M16X1.5 10 18 18 42 17 19 1Q-18 M18X1.5 M18X1.5 12 18 18 42 19 22 1Q-22 M22X1.5 M22X1.5 14 19.5 19.5 47 24 27 1Q-24 M24X1.5 M24X1.5 16 20 20 50 27 30 1Q-27 M27X1.5 M27X1.5 18 20 20 50 30 32 1Q-30 M30X1.5 M30X1.5 20 23 23 57 32 36 1Q-33 M33X2 M33X2 22 26 26 63 34 41 1Q-36 M36X2 M36X2 25 25 25 61 38 41 1Q-39 M39X2 M39X2 28 26 26 65 41 46 1Q-42 M42X2 M42X2 32 28.5 28.5 70 46 50 1Q-45 M45X2 M45X2 34 28.5 28.5 70 46 50 Note:In case if you are interested to order the adapter in complete set with sleeve and nut ,it is necessary to insert suffix "RN" after our part no.,for example 1Q-18RN.