Dremel 409 1/4" Cut-Off Wheel Rotary Accessory for Metal, Thin Wood and Plastic | 36-Pack

Dremel makes a slightly thicker one as well, but if you need a small kerf for rewelding metal parts back together, this is better. One must however, be aware they will breal easier if sideways pressure is applied(be sure to wear safety glasses)

The 409 abrasive wheel is my most used wheel and closely followed by the 420. This is best used for small items like small screws and rods etc like in model rc vehicles, aircraft, and boats. I use them for my business of restoring antique clocks, industrial and antique home sewing machines. They are used for cleaning and dressing precision screw heads along with cutting down screws and cutting new slots. You have to use light pressure, slower rpm's and you to remain steady in the cut or they will break as they are only .025" thick. If this is a problem you need to move up to the 420 as they are thicker and slightly more resistant to binding and flexing. I've been using the heck out of them for over 15 years in my one and only Dremel model 395.