This ground block makes it easy to establish a solid ground for arc welding when you can’t find a good place to clamp the lead — as long as you’re welding ferrous metal. Just smack the magnet onto your work piece, then attach your grounding clamp to the stud on top. The stud is spring loaded so that when you attach the magnet it presses against the metal and ensures a solid ground.
This is great for sheet metal and others pieces that your clamp fit around. And at a street price as low as $6, it’s worth it to keep one or two around.
Hell, right now Harbor Freight has it in stores for only $4.