... 4.adequate stocks,fast delivery 5.IADC 517 8 1/2" IADC 517 Kingdream hard rock drill ... .6mm(7 5/8”),200.0mm(7 7/8”)212.7mm(8 3/8”),215.9mm(8 1/2”),222. ... .4(9 5/8”),250.8(9 7/8”)269.8(10 5/8”),295.3(11 5/8”)311.1(12 ... 637,737512,522,532,612,622,632,732Bearing Type:HJ(metal sealed journal bearing) HA (rubber sealed journal ... T, L/C at sight, western unionProducts show 8 1/2" IADC 517 Kingdream hard rock drill ...