Brass end brushes, with 0.3mm diameter crimped wire, allow for fast surface cleaning. One-piece ferrule construction ensures that the stem and ferrule will not become separated during use. The brushes are designed to follow contours and intricate surface patterns. Available in 12mm (1/2") diameter. Shank diameter is 6mm (slightly smaller than ¼”). Maximum RPM is 20,000rpm. Made in China.