Henan Shenlong Petroluem Drilling Tools Co.,Ltd, We are a leading manufacturer based in Mainland China. Our main products include Drill Collar, Non-Magnetic Drill Collar, Heavy Weight Drill Pipe, Stabilizer Etc. We are most competitive in Drill Collar for small size below 4 3/4" and large size above 9" . The below is the brief introduction of our company. Shenlong assures high quality through the below source Shenlong has technology consultants from MIT(Massachusetts Institute of Technology), Shenlong's technicians are most from an important and famous special steel group in China. Shenlong's skilled workers assure high efficiency. Shenlong is ISO9001 Certificate Holder and We produce according to API. Shenlong always pursuits prompt delivery time We have experts from Material Purchasing to Producing to Logistics, We manage every process very efficiently within the shortest time. Shenlong' s price is most competitive Based on the above advantage, our price is the most competitive. If you are interested in any item of our products, you can send us email or call us any time, we will be always happy to hear from you.