Dremel accessories (454) chainsaw sharpening grinding stones are designed for precision grinding and sharpening of ferrous materials such as chain saw blades Precise: Especially designed as chainsaw sharpener, this grinding stone features a precision-ground abrasive for precise sharpening of the chainsaw chain For optimal results, it is recommended to be used with Dremel Chainsaw Sharpener Attachment 1454 Working diameter 4.8 mm; shank diameter 3.2 mm; recommended maximum speed 30,000 RPM Fits with all Dremel Multi-/Rotary tools or other 3,2mm shank size multi- / rotary tools