... ). 20 years experience in well drilling equipments 1.Advantages of our products(1) strong resistance to abrasion and impact resistance.( ... ),9 5/8"(245mm), 11 5/8"(295mm),12 1/4"(311mm), 13 5/8"(346mm),14 3/4"( ... 374mm), 15 1/2"(394mm)16"(406mm), 17 1/2"(445mm),18"(457mm), 26"(660mm) ... ,346,347RPM(r/min)140~60WOB(KN/mm)0.35~1.0Thread Connection7 5/8 reg pinBearing typeSealed bearing and ...