Sandvik's latest DTH and tophammer drilling technologies will deliver great penetration and performance, according to the firm. The company is broadening its DTH offering and intends to offer hammers aimed at three different performance levels. The new RH550 units are the first of this upgraded line-up and are designed as the top grade models for quality, performance and longevity. These replace the earlier Mission units and are being offered in 76mm, 102, 152 and 203mm (3, 4, 6 and 8") diameters. The rest