... , high wear resistance.2. High-precision metal seal.3. Locking roller ball, to adapt to high-speed.4. The use of high ... Pipe, TCI tricone bits, PDC bits, PDC Diamond drill bits, roller rock bits,core bits,all size bits in oilfield,water ... . Thank you for attention me ! Contact: janneM.P.: 0086-13784816938 roller drill bit