used on e or twice and only on wood. cutting paste was never opened. very high quality German tools from ruko website: Product Details UPC: 4007140147912 Diameter: 2/5 - 5/10 - 10/15 - 15/20 Material Specification: HSS Cobalt Brand: Ruko Germany Box Quantity: 5 Peeling cut. Chip removal through the slot prevents chips from clogging the workpiece. Ideal for burr- and chatter-free deburring and countersinking. Applicable for steel, cast iron, non-ferrous and light metals. Best results at low cutting speeds. Countersink with a blade not recommended for full countersinking.
eBay