... the principle of "faith-based, quality of survival and mutual benefit, provides the highest quality products and attentive service for our ... Apply to soft-medium,medium-hard drilling information 6) Bit size:8 1/2"IADC code:5372,products details 3 ... this formation in you inquiry1)the size of the tricone bit.2)the IADC tooth model,like 537G3)plz tell ... the quantity. 8 1/2 215.9mm iadc 517 tricone drill bit