These Dremel 409 24mm cut-off wheels are ideal for cutting metal with limited use on wood and plastic. They make it easy to cut or slot bolts, screws, sheet metal, thin wood, and plastic. The cut-off wheel cuts only along its edge and is designed for use with a 402 mandrel. Specifications include: Accessory Type: Cut-off Wheel, For Use With: 402 Mandrel, Country of Origin: China. Shank diameter is 3.2mm, working diameter is 24mm, maximum speed is 35,000rpm. Supplied in packs of 36.