Drill collar
1. 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.
2.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. A hardness range of 285-341, Brinell Hardness and Charpy “V” notch minimum impact strength of 40 ft-lb at 70OF are guaranteed one inch below the surface.

Drill pipe

Specification of drill pipes
Spec Weight Flat-end Weight External Diameter D Wall Thickness t Grade Upset Type
lb/ft Kg/m inch mm inch mm
2-3/8? 6.65 6.27 9.33 2.375 60.3 0.280 7.11 E?X?G?S Upset
2-7/8? 10.4 9.72 14.47 2.875 73.0 0.362 9.19 E?X?G?S Upset
3-1/2? 13.3 12.32 18.34 3.500 88.9 0.368 9.35 E?X?G?S Upset
3-1/2? 15.5 14.64 21.79 3.500 88.9 0.449 11.4 E?X?G?S Upset
4? 14.0 12.95 19.27 4.000 101.6 0.330 8.38 E?X?G?S Int Upset
4-1/2? 16.6 15.00 22.32 4.500 114.3 0.337 8.56 E?X?G?S Int-Ext Upset
4-1/2? 20.0 18.71 27.84 4.500 114.3 0.430 10.92 E?X?G?S Int-Ext Upset
5? 19.5 17.95 26.70 5.000 127.0 0.362 9.19 E?X?G?S Int-Ext Upset
5? 25.6 24.05 35.80 5.000 127.0 0.500 12.7 E?X?G?S Int-Ext Upset
5-1/2? 21.9 19.83 29.52 5.500 139.7 0.361 9.17 E?X?G?S Int-Ext Upset
5-1/2? 24.7 22.56 33.57 5.500 139.7 0.415 10.54 E?X?G?S Int-Ext Upset