Separating discs are very useful in scoring metal for bending and when cutting tool steel like graver blanks. The discs are very hard but brittle. I use to get really nervous when using these discs to cut because I keep wanting to see if I'm cutting at my marked line or not. Here's a quick tip that helps me a lot:
2. As you can see, you can't get a good view through the disc. It's like trying to drive in thick fog.
4. Now I mount the disc back on the flex shaft after the "enhancement."
6. Another look at the modified disc at high speed.
And of course, ALWAYS wear eye protection when using separating discs. A dust mask is highly recommended as that disc can kick up a lot of dust.