Following the launch of polycrystalline diamond (PCD) tipped parting-off tools, Hampshire-based Horn Cutting Tools Ltd has now introduced new step drills that have cutting edges tipped with PCD for drilling, boring and countersinking non-ferrous metals, that can be used for instance in the production of aluminium wheels.

The tool system allows greater drilling precision and produces better surface quality due to the sharp cutting edges. The tools permit high cutting parameters during machining, which makes it possible to reduce the processing time and hence the cost per component in series production.

Horn only offers the PCD-tipped step drill as a special tool. The PCD tip is available on tools of 4mm diameter and above. All variants have an internal coolant supply and the carbide monobloc shanks, which are available in all common DIN diameters from 6 to 25mm, ensure good vibration damping during machining. The monobloc shank is available in a steel variant from a diameter of 32mm.

PCD is a synthetically produced, extremely hard, intergrown mass of diamond particles with random orientation in a metal matrix. It is produced by sintering together selected diamond particles at high pressure and temperature. Economical machining of steel is rarely possible due to the affinity of iron for carbon in the diamond. As the temperature increases, the carbon from the diamond diffuses into the steel, severely limiting tool life.