We supply slick drill collars, spiral drill collars and non-magnetic drill
collars; their sizes are from 3-1/8 to 11 inches. Besides the drill collars in the table below, we can supply other drill collars at customers'
request.Materials:
Drill collars are manufactured from AISI 4145H modified steel, and are supplied in the "as rolled" surface finish condition. Alternative surface finishes are available.
Trepanning and Heat Treatment:
Drill collars are trepanned and drifted to API Spec 7-1. Full-length heat-treatment processes ensure that mechanical properties meet or exceed API Spec 7-1 requirements. A hardness range of
285-341, Brinell hardness and Charpy "V" notch minimum impact strength of 40 ft-lb at 70 F are guaranteed one inch below the surface.Traceability:
Drill collar material and process traceability are maintained from receipt of the mill's certified raw material to completion of manufacturing. Serial numbers are die stamped on bar
bodies.Rigid Inspection Procedures:
We inspect all our drill collars to ensure compliance with API SPEC 7-1 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 copper plated to improve resistance to corrosion.
Slip Groove, Elevator Groove and Size:
Lake offers optional slip and elevator recesses to improve handling efficiency and safety. Unless otherwise specified, slip and elevator recesses are machined in compliance with API spec 7-1
guidelines.
Contact information
Attn: Melody Wang
Mobile: 0086-18307551623 (wechat/whatsapp)
Email: melody(at)lakepetro.com