OD: 3-1/8”——10” Size: 3-1/8”——10”

China CNGC Shanxi Fenglei Machinery Drilling Co. (SFMC) is currently the largest specialized production base for Drill Pipe, Drill Collars, HWDP, Kellys in China.

SFMC has been manufactured drill collars for more than 30 yeas and was the first company to manufacture drill collars in China.

All SFMC drill collars are made of AISI 4145H or 4145H Modified alloy steel in accordance with API Specification 7-1, API Recommended Practice 7G and API Specification Q1 latest Edition.

The bores are trepanned from one direction with no mismatch. All drill collars are Q&T full length by SFMC’s own unique Power Frequency Induction Heating Treatment machine designed by SFMC, to ensure the Charpy “V” notch minimum impact strength of 40 ft-lb at 70F and hardness from 285 to 341 BHN which are guaranteed one inch below the surfact.

SFMC also manufactures special Drill Collars with Spiral, Slip and Elevator recesses, hardbarding. The Square Drill Collars is available.