IM 2019 November 19 | Page 51

ROCK TOOLS The Boart Longyear DriftMaster™ thread geometry with carburising heat treatment is designed to maximise resistance to wear under the harshest drilling conditions increased while still maximising penetration rate or tripping out rods to change bits. Given the low hardness of the formation in this example, Longyear Blue and Green bits are good solutions. Tested and proven recently at a site in Ontario, Canada, Longyear bits showed a stark contrast, over previously preferred bits, with an increase in penetration rate and bit life. Using a combination of the Longyear Blue and Green bits, driller’s averaged 109 m per bit and increased penetration rate. When drilling softer formations at site, the drillers used the Blue bit and found this bit to be incomparable when looking at the production rates and bit life. The two Longyear formulas combined yielded a 60% improvement in life and an 8% increase in productivity. Using patented technology, Longyear bits have diamonds that are chemically bonded to the matrix creating a more versatile, faster penetrating, and a longer-lived bit. In production drilling, global field testing of Boart Longyear’s new series of DriftMaster™ rods and bits “has exceeded expectations As an example, the challenge in softer abrasive formations, such as greenstone and sedimentary formations, is to pick a diamond drilling bit tough enough to get good life without sacrificing penetration rate. With requirements to increase productivity, a driller cannot simply pick the toughest bit available; bit life needs to be leading to extended trial durations, extensive sample sizes, and very positive responses. Customers are seeing the benefits from increased productivity and lower overall costs.” Designed and manufactured with a unique thread profile, DriftMaster top hammer rods and bits boast improved strength and durability compared to standard thread designs. Optimising the load distribution and contact area, the DriftMaster thread geometry with carburising heat treatment is designed to maximise resistance to wear under the harshest drilling conditions. A tapered thread profile provides superior rod-bit make-up and breakout characteristics. Boart says the DriftMaster offers increased strength through stress reduction in two key ways. First the tapered profile provides an increased material cross-section at the base of the threads. Second 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 means more drilling time and more productivity. DriftMaster rods are available in 35 mm hex cross-sections for use with standard, Retrac, and Straightrac button bits from 43 mm to 64 mm. Dome and pilot reamers – including the optional, patented, high-productivity back-reaming RazorBack™ bit, are also available.   Power Carbide™ options from Sandvik Sandvik has chosen to gather its most powerful cemented carbide grades into a new group called PowerCarbide™. “The range comes with a combination of strength, hardness, toughness and wear resistance. All of these properties significantly enhance both drilling performance Brunner & Lay Mining g & Construction Tools American made and Family owned since 1882 PAVING BREAKERS DEMOLITION TOOLS ROCK DRILLING American Made! Quality, Performance, Value and Reliability, since 1882. 1510 N Old Missouri Rd, Springdale AR 72764 ph 479 756-0880 fx 479 756-5366 Call (800) 872-6899 or visit BrunnerLay.com