A new range of high-precision, abrasive deburring tools made from aluminium oxide (alumina) has been introduced for use on static platforms such as machining centres, mills, drilling machines, special-purpose machine tools, industrial robots and hand-held power tools.

Available in the UK through NCMT, the Japanese-made tools from Xebec Technology comprise rods consisting of 1,000 alumina fibre filaments measuring just 10μ diameter. The self-sharpening cutting action is on the tip only and without an abrasive effect on the sides of the rods.

Dozens or hundreds of parallel rods go to make up a hollow, cylindrical tool rather like an elongated cup. The rods are prevented from unduly splaying by a metal sleeve whose inner diameter is approximately the same as the outer diameter of the tool. Only a short length of the fibre rods protrudes at any given time from the end of the sleeve, which is retracted by hand occasionally to compensate for rod wear. Periodic offsets also have to be entered into the machine tool control.

The product design bears out Xebecs assertion that theirs are precision deburring, deflashing, finishing and polishing tools, more akin to an end mill than a wire brush, which is relatively crude in its application. Moreover, the manufacturer claims that its method of growing the fibre filaments ensures that the alumina content is very high at 70% by weight, compared with just 30% in conventional, abrasive-impregnated nylon wires.

Fibres are available in two grades, course and fine, and tools may be from 6mm to 100mm in diameter. Despite their high metal removal rate, the tools wear slowly due to their high alumina content and also as a result of their resistance to high temperatures as well as to water and oil-based coolants. The tools are equally capable of cutting dry.

Xebec has also found a way of growing the fibres radially to form a stone-like tool similar to a mounted point, but with considerably better longevity and controllability when machining. Available in diameters from three to 20mm, they are called Cross-Hole Deburring Tools, as this is deemed to be their primary application. They have a flexible shaft and are intended for efficient removal of burrs with a base thickness of 0.2mm or less. There is also a solid brush version for finer burrs of under 0.1mm diameter.

The cross-hole deburring tools may be used with static or hand-held machines. Specifically for freehand deburring, there is an additional range of solid, 6mm diameter, alumina fibre filament brushes with shaped ends.  A primary application is EDM scale removal from moulds and subsequent polishing.

www.ncmt.co.uk