... 517 8 1/2" IADC 517 Kingdream hard rock drill bits HAS series for oil well 1.Introduction about us ... bits, steel tooth bits, insert tooth bits, roller bits, drill bits, drilling tools etc. we have been in line with ... to meet your special need. 3.Sizes and types of drill bits we can privide: 60mm,65mm,76mm,93mm,95mm, ... /2”),508(20”),558(22”),609.6(24”)660.4(26”) Steel tooth(IADC)111, 121,131117,124,126,127 ...