With the announcement of its new series of DriftMaster top hammer rods and bits, Boat Longyear has created tooling that has been designed with a unique thread profile for added endurance and strength in the most demanding tunnelling, bolting and drifting applications.

"Global field testing of DriftMaster products has exceeded expectations leading to an extended trial duration, extensive sample size and very positive responses," said Jeff Hogan, product manager for top hammer tooling at Boart Longyear. "Test results from the field strongly aligned with our design goals of significantly improved durability compared to standard threads. Our customers will benefit from increased productivity and lower overall costs."

For maximum productivity, DriftMaster offers increased strength through stress reduction in two key ways:

1. The tapered profile provides an increased material cross-section at the base of the threads and
2. The asymmetric thread geometry minimises stress concentrations. The lower stress combined with deep case hardening allows for a significant increase in cyclic load handling capability. More load cycles mean more drilling time and more productivity.

Optimising the load distribution and contact area, the DriftMaster thread geometry is designed to maximise resistance to wear under the harshest drilling conditions. Combined with the wear resistance associated with carburizing heat-treatment, the DriftMaster endures the toughest drilling conditions.

To further improve productivity, the tapered thread profile offers superior rod-bit make-up and breakout characteristics for more drilling time.

DriftMaster is being introduced in 35mm hex cross-sections for use with standard, Retrac, and Straightrac button bits from 43mm - 64mm. The initial offering includes dome and pilot reamers - including optional RazorBack, a patented high-productivity back-reaming bit.