They are called Norton rapid strip discs. The blue variety is available at the big box stores, hardware stores, and some paint stores. There is also a black variety that is their industrial line and I have only found that at welding shops or on-line. For me, the black have lasted longer than the blue but either discs work great! They are available to fit a grinder as mentioned but also come in a wide variety of other shapes and sizes. I have used a wide variety of products for stripping to bare metal. They all have their uses but the Norton rapid strip discs have worked the fastest and lasted longer than anything else I have tried for your described use.
Chuck
