To cut hardened steel and stainless steel you will need the PLUS model
The UNIBURR is a deburring tool bit that quickly repairs damaged bolts to thread nuts in place once more, saving you time and money. The UNIBURR simplifies the repair process, potentially fractionalizing repair time, as well as bypassing the need to replace expensive or hard to find hardware while keeping safety at a previously unattainable level.
This tool works by way of shearing metal layer by layer. So there are some important things to know about using the Uniburr. The most important thing to know is this: THE SLOWER THE BETTER. Using the lowest speed on your drill (0-600 RPMs), apply decent pressure and the tool will do the rest. Remember that we’re not making metal pencils; We’re removing damaged threads to allow an easy nut start. Remove only the amount of material from the work piece that you need, and you will preserve the life of your Uniburr.
Most repairs only require removing a single thread. The Uniburr is a cutter, and just like a drill bit it will reach the end of life depending on how you use the tool. Slow speed along with no unnecessary cutting and the use of cutting oil or another lubricant will bring your Uniburr long life. Refrain from turning every work piece into a pencil, and you’ll keep the Uniburr cutting edge sharp for much longer.