We created this video to help explain the differences in grit particle size.
These four blocks here were designed to show the relative size of the different grits. This is a 220 grit, 600 grit, 1000 grit, and an 8000 grit. You can see there is a great disparity in size.
Right here would be something we might call an extra course grit. The relative size of this one compared to our smallest one is obviously very large, and this one we might call a 220 grit with a 60 micron particle size.
If we compare that to our next step here, this one would be 600 grit with a 25 micron particle size. So as you can see it is quite a bit smaller, so basically this one (220 grit) is used for very coarse sharpening, and this one (600 grit) is to further refine the edge.
And then each of your subsequently smaller stones and corresponding grit sizes. This one here would be equivalent to 1000 grit. And this one here would be 8000 grit. So obviously this one (8000 grit) is going to leave a very polished looking edge, and this one (220 grit) is going to leave a very coarse edge. This one here (8000 grit) cannot be used to do the job of this one here (220 grit); you're going to be there all day trying to sharpen your knife.
You start with this one (220 grit) and progress down to the finer ones. If you have a dull edge you wouldn't want to start with one of these finer ones. As you can see, just in relative size this one (8000 grit) would take considerably longer.
If you have any questions about what grit you should use, please just give us a call: 1-800-351-8234