1.our Drill Collars are manufactured from AISI 4145H modified steel .
2.Drill Collars are trepanned and drifted to API Spec.7. Full Length Heat Treatment processes ensure that the mechanical properties meet or exceed API Spec. 7 requirements.
3.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.
4.Standard Drill Collar Features & Options
API pin stress relief groove and box boreback
An API pin stress relief can be used on all drill collars and downhole tools. It is a recommended option in situations where fatigue can occur as a result of bending. By removing any unengaged threads in the high stress areas of the drill collar connection, it is less likely to crack due to fatigue because the bending will take place in the area of the connection with smooth surfaces that are free of stress concentrations.
Phosphate coating
All threaded connections can be treated with a phosphate coating to help prevent threads from galling.
Spiraling
Three optional spiral grooves can be placed on the outer diameter of the collar to allow the mud to circulate freely around the drill collar. This is to equalize the pressure as well as to prevent a seal forming. This will help reduce any chances of differential sticking.
Hardbanding
Optional hardbanding is available in various materials. Drill collar hardbanding is normally applied flush to the outside diameter of the bar. Other configurations are available upon request.
Elevator and slip recess
Optional slip and elevator recesses are available to improve handling and safety.
These two features can be used together or separately. These options are cut as per API recommended practice 7G.
We offer customized drilling stabilizers according to API or for all customer's requirements and common drilling methods. This includes different sizes, shapes as well as several types of weld on hardfacing and machining.
