Such is the breakthrough in the flat MultiDrill MDF series of coated solid carbide tools that spotfacing/counterboring can be performed using tools as small as 0.3mm up to 20mm diameter with depth to diameter ratios of 2:1.
In addition, the MDF series can be used for directly pre-tapping holes in thin sheet material, and for cross-drilling applications and, such is the geometry and optimised cutting edge design of the tool, that exit burrs are significantly reduced when compared to more general purpose tools. Meanwhile, the wide chip pocket and shape of the rake face, means effective chip evacuation is enhanced.
Due to the rigidity of the tool it can be applied to a wide range of materials such as soft steel and aluminium alloys, alloy steel up to 300 HB, hardened steel up to 50 HRC, stainless steel, grey cast iron and ductile iron.
On a recent application producing a 3mm diameter through hole, pitched at 60° to the flat material surface and drilled through the 8mm wall of the component for the automotive industry in C35 material, previous chipping problems on the part were completely eliminated. The MDF series tool was run at 80m/minute with a feed rate of 0.045mm/revolution.
An illustration of reducing the effects of burring at the exit of a hole, compared to conventional drilling in 15CrMo5 material, a 5mm diameter MDF tool reduced burr height from 0.44mm previously to just 0.18 mm over a batch of 150 components. The MDF tool was run at 65m/minute, 0.12mm/revolution feed through the 10mm thick material.
Sumitomo Electric Hardmetal www.sumitomotool.com