The male‐female design configuration eliminates the need for a separate coupling resulting in faster additions and removals to the drill string, and reduced hole deviation due to fewer threaded connections.

End forms are fully heat treated to provide:

• Market‐leading wear resistance during drilling and coupling or uncoupling.
• Reduced galling, chipping and surface damage.

Boart Longyear’s EL threads and mid‐body diameters up to 70 mm combine to provide:

Straighter holes—resulting in fewer holes required, more consistent fragmentation, increased efficiency, and reduced operational costs.

Hole diameters up to 152 mm (6”)
Increased use of the power available from the latest generation of top hammer drills and efficient energy transfer for improved penetration rates.

Easier uncoupling resulting in extended drill string life, reduced time per hole and lower drill maintenance.