T6 series core barrel T6 series: T6 76,Website:http://www.yikuangdrilling.com, T6 ... , NX, HX, TBW, NQTT, HQTT, TNW, 412F, BTW, TBW Chinese standard: 56mm, 59mm, 75mm, 89mm, 91mm, 108mm, 110mm, 127mm, 131mm, 150mm ... , 170mm, 219mm, 275mm Russian standard: 59, 76, 93, 112, 132, 152 mm