Sharpening stone (emery grinding wheel) for meat slicers, size 45 × 13 × 6 mm (diameter × thickness × centre hole). It is the wear part of the built-in sharpener assembly: mounted on the shaft, it restores the edge of the circular blade at every sharpening pass. Compatible with FIA Boston slicers and Berkel models with the same fitting, as well as any machine using this size. Note: the 13 mm thickness is wider than average (the most common Ø45 stones are 8 mm thick), so this is a wheel specific to sharpener assemblies that require this width. The coarse grit removes more metal and restores the cutting-edge profile on worn or nicked blades: it is the first wheel in the sharpening cycle, followed by the fine grit for finishing. The two wheels work as a pair in the sharpener assembly: for proper sharpening it is best to have both grits and to replace the stone when it is worn or glazed. Before purchasing, check the three dimensions (diameter, thickness and centre hole) on your machine: these are the figures that determine compatibility regardless of the slicer brand.