Because it cannot fully evaluate the dull bit characteristics, IADC published the Eight Point dull bit Grading scheme to replace the old scheme.

由于其不能全面反映钻头的磨损情况，后来又制定了钻头磨损八位定级方法。

youdao

Because it cannot fully evaluate the dull bit characteristics, IADC published the Eight Point dull bit Grading scheme to replace the old scheme.

由于其不能全面反映钻头的磨损情况，后来又制定了钻头磨损八位定级方法。

youdao