1750 or 3500, slow or fast, 6" or 8"… it doesn’t matter. Norton’s 3X grinding wheels are the fastest cutting, coolest wheels on the market. Norton’s patented SG grain gives the 3X’s an incredible burn free cut with controlled micro grain fracturing that constantly exposes fresh grain. This continuous refreshing of the surface helps speed up metal removal and keep your tools a lot cooler. Faster cutting and less burning also means longer wheel life. How much longer depends on you but from our experience – these may outlast your grinder.