Inca Geometric beats European competition

The first of a series of batches, involving 20 customer-supplied, square section ring blanks, produced from compacted resin-bonded powdered granite, are being machined at the Chartham near Canterbury facility. "We have to take considerable care to prevent damage and be very aware of the nature of the powdered material as each ring is machined," said managing director Mike Cain. " We also have to ensure each ring is totally blemish-free and that a perfectly smooth matt finish is maintained." The finish rings are 820 mm diameter by 50 mm thick with a 700 mm profiled bore. Each ring is rough and finish turned to ensure it is perfectly flat, square and concentric then located on a vertical machining centre where three special formed equi-spaced deep slots are pocket milled in the outer face. A series of adjacent drilled location holes plus drilled, counterbored and tapped holes are also machined around a pitch circle diameter. Following machining and inspection, each ring is individually packaged prior to shipment in order to prevent damage.