It depends on the surface you wish to prepare and the blasting equipment you plan to use. We carry six different grades of abrasive products that range from our most coarse product, 1240, to our finest product, 4080. View a complete listing of our copper slag (aka iron silicate) grades as well as the recommended uses, mil profile, and preferred nozzle size for each product. To help you find the blasting abrasives that best suits your needs, take a look at our Product Comparison Guide.