A high quality 4-1/2" Zirconium Grinding Wheel made by Pferd in Germany. This Zirconia alumina (Zirconium) grinding wheel is designed for steels & cast iron with excellent material removal rate, & very long service life. 4-1/2" diameter of wheel. 5/8-11 Threaded hub. 1/4" thickness of blade. Depressed center type blade.  Made in Germany.,Established near Cologne, Germany in 1799, the Pferd brand name is synonymous with outstanding premium-quality tools & abrasives. Today, we manufacture more than 7,500 Pferd brand grinding, cutting & surface finishing tools, & a complete range of power & maintenance brushes. Pferd 4-1/2" Zirconium Grinding Wheel - 1/4" Thick ~ 5/8-11 Thread