Following the recent successful launch of its top centre drill bit, Sandvik launched the new UNIFACE down-the-hole range of drill bits at MINExpo. UNIFACE drill bits incorporate the largest upgrade to DTH bits in decades, with long bit life essential in cutting costs and improving productivity.

Having the correct bit is a crucial factor in the performance of any drilling operation. The UNIFACE bit design from Sandvik incorporates several features that, when combined, significantly improve bit life and productivity. In fact, the service life of the bit can be as much as 80% longer than current Sandvik bits. UNIFACE is designed for optimised flushing that gives a more even wear of the gauge, increasing the life of the bit. In order to achieve a consistent penetration rate, the buttons have been placed so that they always hit fresh rock.

• Raised centre ensures centre buttons hit the rock first, resulting in even better collaring and straighter holes
• Optimised number and placement of flushing holes (depending on diameter size, either three or four), with equal distance between flushing grooves evenly distributing air flow and reducing wear on gauge buttons
• No face slots ensures that the air is more evenly distributed around the bit, resulting in a more even wear. It also facilitates better clearing of cuttings in front of the bit and makes it possible to evenly place the buttons
• The evenly-placed buttons enable the UNIFACE bit to cover the entire cutting area with just 90^o rotation. This means no double breaking of the same rock or missed breaking, enabling more even wear of the buttons and resulting in increased button life. The even load distribution on all buttons also reduces the risk of button breakage.

The tool life improvements delivered by the UNIFACE design also yield significant health and safety benefits, since operators spend less time changing tools. “The new bit design essentially delivers more drill meters per shift compared with a standard bit, thanks to less frequent bit changes,” says Johan Bergquist, Global Product Line Manager DTH Tools, Sandvik Mining and Rock Technology. “With UNIFACE, we launch an updated and improved DTH drill bit design. The result is a design with a number of features that are new to the industry and that significantly increase bit life, while maintaining penetration rate.”