I picked up several pieces of 90 degree angled aluminum stock from my local Home Depot. Pic 1 shows one with 80 grit paper glued to one edge using 3M77 spray adhesive. Pic 2 is with it on edge exposing the sand paper. I can use this as a 90 degree sanding fence or flip it over to sand an angled surface. This one does NOThave equal length sides so it won't make a 45 degree angle. Use one with equal length sides and the resulting angle will be 45 degrees.