Materials: 

Drill collars are manufactured from AISI 4145H  modified steel, and are supplied in the" as rolled" surface finish condition. Alternative surface finishes can be provided.

Trepanning and Heat treatment :

Drill collars are trepanned and drifted to API Spec 7. Full-length heat-treatment processes ensure that mechanical properties meet or exceed API Spec 7 requirements. Traceability:

Drill collar material and process traceability are maintained from receipt of mill¡¯s certified raw material to completion of all the manufacturing. Serial numbers are die stamped on bar bodies.

Rigid Inspection Procedures:

We inspect all our drill collars to comply with API standards . These inspections include visual dimensional checks as well as ultrasonic inspections over the entire body of the drill collar.

Cold Rolling:

Drill collar thread roots, as well as elevator recess upper radius, are cold-rolled. Cold rolling creates a compressive recess upper radius stress condition that increases fatigue life by minimizing crack initiation.

Phosphate-coated or copper plating:

All connections are phosphate-coated or made copper plating in according to clients’ requirements to improve resistance to corrosion.

Thread protectors:

Our company offers steel and cast steel and plastic steel thread protectors for its drill stem products.