... 8 1/2" Steel Tooth Rock Bits (IADC217) Hejian HuanYu Petroleum Machinery Co., Ltd.. We are specialized in tricone bits, steel tooth,TCI rock ... bits, Milled steel tooth bits).: "8-1/2","9-1/2","12-1/4","15-1/2","17-1/2 to 26,We have been serving the drilling ... ,tricone bits,rotary bits1. Cutting Structure of this series tricone rock bit ... Packing TermsT/T and L/C are acceptable.( ... days.3.Can I expect a ...