Aptly named ‘Lite-Cut’, a new series of gun-drills from Botek incorporating a conical chip-breaker form and a special nose-grind is said to require 30% less power when machining.

As a result, higher penetration rates can be achieved, especially in more-difficult materials, while creating shorter and more-compact chips means that swarf is easier to evacuate with standard-pressure coolant.

Supplied by sole UK agent Mollart Engineering, Chessington (www.mollart.com), Lite-Cut gun-drills are available as Type 110 single-flute brazed tools or Type 113 solid-carbide tools.

Type 110 brazed solid-carbide-tip cutters are available in diameters between 1.85 and 51.2mm; Type 113s, which incorporate a kidney-shaped coolant channel, are available in diameters between 1.5 and 12mm.

Type 110s also incorporate brazed-carbide bearing pads which, in conjunction with the cutting forces generated, pressurises the pads against the wall of the drilled hole to support the cut and create a burnishing effect plus a high-quality surface finish.

Drill diameters between 1.85 and 7.059mm have a single feed hole for coolant, while drill diameters between 7.06 and 51.2mm have twin feed holes.

Holes with depth-to-diameter ratios up to 40:1 can be drilled in a single pass, according to Mollart. Type 113 drills are available for holes with depth-to-diameter ratios up to 100:1.