Diamond brazed dry drill bit using special technology, vacuum brazed diamond, diamond and the substrate to ensure a solid, a blade because of its high chip removal space, ensure maximum sharpness. Can be used dry, add water, a better effect. Long life, high efficiency, is an excellent alternative to electroplating. Diameter:15-100mm.Connection: M14 and 5/8"-11 thread. Different arbor sizes and diameter are available upom request.