Superior Electric GA-M1058-1 Grinder Adapter Converts M10 x 1.25 Grinder Arbor Threads into 5/8" - 11 Arbor Spindle. This grinder arbor adaptor is machined from a sold steel stock rod that allows you to convert your grinder arbors from a M10 x 1.25 arbor to an 5/8"-11 threaded arbor spindle. Replaces OEM P/N 323015-A, P/N DW4900.