Foredom Carbide Miniature Set, Style AK200, 8 piece. These burs are ideal for use on hard wood and most metals including stainless steel, steel alloys, cast iron, etc. 2.35mm (3/32") shank. 1-3/4" overall length. 100000 RPM Max Speed. Made in USA. Includes bits 10224, 10227, 10228, 10231, 10233, 10234, 10232 and 10229.