drill bits and PDC bits which used on the oilfield and water well, the sizes: 5 7/ 8" --17 1/ 2" ( both insert drill bits and steel tooth bit) 2.Drill pipe Accord with API 5D latest edition .Has been awarded the certificate for compliance with standard ISO 9001-2008 GB/ T 19001-2008. Steel Grade: E-75, X-95, G-105, S-135 O. D. Range from 2" ( 60.3mm) to 6" ( 168.3mm) Type: Internal Upset, External Upset, Internal and External Upset. With competitive price and high quality. If you are interested in our products , please feel free to contact with us by drillpipes@ yahoo. cn Website: www.drillpipes.net