... bitDrill stringTopDownTopDown6152.412151800~9001,000~1,1001,200~1,4001,400~1,600NC38NC38NC383-1/2REG6-1/4158.76-1/2165.17-1/2190.515916517857711,0001,6001,800NC46NC46NC464 ... 000~1,2001,600~1,8001,800~2,000NC46NC504-1/2REG8 -1/2215.98-3/4222.29-1/2241.317819771800~1,0001,000~1,2001,600~1, ... 200~1,3002,000~2,2002,000~2,200NC617-5/8 REGAny question,please contact us!Skype:angela257000 API-7-1 high quality ...