短語詞組短語coring cone bit 牙輪取心鉆頭coring g bit 取芯鉆頭PDC non coring drill bit PDC 無心鉆頭hard metal coring bit 硬質(zhì)合金取心鉆頭coring bit with diamonds 金剛石巖心鉆頭non -coring bit 不取心金剛石鉆頭percussive coring bit 沖擊鉆探取心鉆頭coring bit breaker 取心鉆頭裝卸器reverse circulation coring bit 反循環(huán)取心鉆頭 返回 coring bit