A Range of belts made to fit the Robert Sorby Pro-edge machine and Axminster Trade Ultimate Edge Sharpening SystemZirconium belts (blue) are widely used in industry for metal grinding, they cut well and have a good lifespan, they are self sharpening so excess pressure will cause rapid wear, Phoenix Naylors belts are manufactured in Chesterfield and are the good quality at a good price. Klingspor Zirconium belts are excellent quality at a good price.
Ceramic are tougher than Zirconium, should have a longer life and are available in higher grits.