Excellent chip removal, outstanding tool life, high productivity and at the same time brilliant surface quality – these features have been considered by Mikron Tool, a Swiss cutting tool manufacturer for the development of their small high performance CrazyDrill. These requirements also have to be met when machining small holes into Aluminium. Cutting speeds of more than 300 m/min and feeds of 0,5 mm/rpm are normal cutting parameters.
The standard execution of CrazyDrill is available with either two or three cutting edges, with internal cooling for diameters of 0,4 to 4 mm and lengths up to 15 x D. These dimensions however are not the limits for this tool. In close partnership with customers, the tool specialists from Mikron Tool have developed drills to lengths of 30 x D with the high performance CrazyDrill cutting geometry. The execution of these, depending on the operation to be performed, can be straight fluted or helix and also with stepped diameters.
The focus for the definition of all tools for Aluminium machining is always based on the operation to be performed, on the quality and the quantity of parts to be produced. Depending on the material or the kind of alloy, a deviation from the standard execution to other cutting geometries or to another coating or even to another carbide type might be advantageous. Thus the customer always has the certainty the cutting tools will provide optimal performance and guarantee a maximum of efficiency.
A sub-supplier for the automotive industry for example has resolved his drilling challenge for a die cast gear ring (GD-AlSi9Cu3) by using a standard CrazyDrill Alu with the following parameters: n = 15’000 min -1, f = 0,3 mm/rpm und fc = 450 mm/min. At these conditions he managed to drill 36 holes/workpiece, with a diameter of 1,5 mm and a depth of 5 mm getting a tool life of as much as 150’000 holes.