High quality alloy steel tubing. Consistent concentricity, straightness and heat treatment.
Tapered, coarse threads (three threads per inch) provides easy make and break. Load efficiency of 30% provides sufficient strength for average applications.
THRU-WALL HEAT TREATMENT
Heat treated box threads provides 140% material strength which significantly increases thread wear life.
Boart Longyear is the only major manufacturer in the industry to case-harden threads.
Significant research, development and field testing has resulted in a hardening process that is unmatched.
Pin thread crest is hardened to nominal 60HRC to eliminate damaging ‘adhesion’ wear.
Eliminates the transfer of wear material back and forth as seen between threads of equal hardness, leading to large scale wearing and joint seizing.
Some of the features of Boart Longyear drill rods