Drill collars we produce arew made from 4145H forging or rolling mocified steel.We manage our production and inspectioin process strictly according to the API SPEC7 requirements. All connections are phosphate -coated to improve resistance to corrsion. We can also deo copper plating according to clients''  requirements. We offer slip groove ,   elevator groove  and provide thread protector for both pin and box.

Different  sizes we produce are form 3 1/2"  to 11" , our strength is large size like above 9" and small size like below 4 3/4

Shonglong promises our products with superior quality , long life , short delivery time and competitive price.

Welcome your enquiry any time!