What You Get: This WETOLS rivet nut tool parts include 11 pcs mandrels. Size: M3, M4, M5, M6, M8, M10, M12, 3/8-16, 5/16-18, 1/4-20, 10-24. It's easy to find the one you need. Design of changing mandrel by hand: Make it simple to change mandrels and nose pieces.