API 7-1 SERIES Drilling Collar

Drill Collar is the basic component in the BHA which provides weight on the bit for drilling and keeps the drill string in tension.

OAK Drill Collar is manufactured from AISI 4145H modified quenched and tempered steel and is heat treated along its entire 

length for uniform toughness and durability. Strict metallurgical tests are performed per specifications to ensure that the heat

 treatment produces consistent and maximum hardness through the depth of the bar.

     Technical parameters of common DC specifications