Rotary burr, conical point, single cut, 55 mm long, 12.6 mm thick, made of alloy steel. Designed for professionals and DIY enthusiasts. Includes 6 common shapes: Dome cylinder, rounded shaft, concave arc with ball point, cone, cylinder, inverted cone. The double chamber is more suitable for materials with relatively low density. Universal size 6 mm shank, compatible with all electric and cordless drills, pneumatic tools, grinders and other rotary tools. Durable and reliable Machining hardness reach up to HRA85. Can replace a small grinding wheel for most jobs, without creating dust pollution. Processing all kinds of metals (including all kinds of hardened steel) and non-metallic materials (such as marble, bone, jade). Use on drills, presses, lathes, electric or pneumatic hand-operated or flexible shaft devices. Can replace a small grinding wheel for most jobs, without creating dust pollution. Safe and reliable, can reduce labor intensity. Product size: The length of the 6-piece set (55 mm) is the same size, the shank diameter is 6 mm, and the grinding head diameter is 12.6 mm and 6 mm. Product color: silver Delivery quantity: Six pieces