A precision machined steel bush for accurate fitting of grinding wheels to bench grinders. It helps to overcome the problem of grinding wheels not running true. It is intended for 6 inch bench grinders with grindstones 20mm or 25mm wide. It will only fit 1/2 inch (12.7mm) grinder shafts and 1,1/4 inch holes in the grindstone. Outer diameter 50mm.
