Here's how to turn one tool into many-swap out different arbors. While it's nice to have both angled and straight die grinders with each of these arbors in them, most home users won't need to buy two or three extra grinders. But that's OK since the arbors are easy to switch out. On the left is the arbor for the flexible 3-inch Power Loc discs, and on the right is one for cutoff wheels with a 3/8-inch shank. Each air tool comes with simple wrenches to swap out arbors.