The rate of penetration of PDC bits relates closely to its self-sharpening property.This relation can be tested through rig test which is performed with standard PDC test bit.是什么意思_The rate of penetration of PDC bits relates closely to its self-sharpening property.This relation can be tested through rig test which is performed with standard PDC test bit.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句