We offer Drill collar. Shenlongs drill collars are manufactured from 4145H modified steel.Drill collars are bored and drifted to API Spec7-1 and fully heated to meet or exceed the mechanical property requirements of API Spec7.Hardness range of 285-341HB and a charpy V notch impact value of 54joules are guaranteed one inch below the surface.
On enquiries and orders ,please specify:
Slick or spiral;
Drill collar OD;
Drill collar bore:
Length of drill collar;
Connection type;

Stress-relief grooves:
Stress-relief grooves decease the frequency of fatigue failures by improving the bending strength of pin and box connections and reducing high stress concentrations. Sress-relief features are manufactured in compliance with API Spec7, unless otherwise specified by customers.

Slip recess and elevator recess :
Shenlong offers optional elevator and slip recesses to improve handling efficiency and safety.The
upper radius of elevator recess is cold-rolled to increase product life.Slip and elevator recesses can be used together or separately. Unless otherwise specified,slip and elevator recesses are machined in compliance with API RP7G guideline.

You can contact us if you want to order this product.