Features

1,Except AISI 4145H by API 7-1 standard, also produce proprietary steel grade which combined the ductility and hardness both better than the API steel grade,   and also produce according to your requirement to adapted to down hole situation

2, Proprietary designed intermediate frequency heat treatment technique to make full-length heat treating so improve the service life.

3, Complete examination methods such as UT, MT is applied to examine out any flaw that guarantee the flawless products.

4, Modified  machine is applied to bore the inner bore one-off so that guarantee  the smooth inner wall.

5, 5 axis CNC milling machine to precisely machine the spiral, elevator, slip grooves of the spiral drill collar.

You may choose or be advised:

   1, Stress-relief groove

   2, Hard banding

   3, Cold rolled thread roots.