Here are a few of mine, 1 or 2 of them are constantly with me. Recently, after one incident, I realized that it does not matter how good the knife is, but if you do not take sharpening devices with you, then all kinds of random circumstances can bring unexpected problems. It's like taking a flashlight but not taking spare batteries. I used to only carry the Norton Fine India stone with me (~400 grit). Now I wear 2 more diamond stones - DMT Extra Coarse (60 micron / 220 mesh) and Eze-Lap Coarse (250 grit).
Grit - mesh - micron quite a confusing system, but it's good that there is a translation table
Using the right gem cutting abrasives is critical for gem cutters. Our grit, mesh, and micron conversion chart will help you choose the correct material.
Judging by the table, DMT has some kind of own measurement system, since it turns out that my ezelap and this dmt should have the same grain, but in reality dmt is much rougher. But it doesn't matter, they do their job great.
The situation I mentioned at the beginning was this - I went to a party with friends and we make fried meat, all their knives turned out to be very blunt. I sat down to sharpen knives, a few years before I gave them knives from well-hardened D2 ~ 63 HRC and another knife Aus-8 ~ 57-58 HRC, there were also several Tramontina 420J2 ~52 HRC. While I was sharpening, I gave my knife from S30V for work, so as not to waste time. Sharpening D2 with these 3 stones above took about 10 minutes, sharpening Aus-8 took about 5-6 minutes, sharpening Tramontins took about 2 minutes. I gave all the knives to the rest of the people to get it over with. When it was over, I looked - all the knives, including mine, were completely dull again. The reason was the following, these are the cutting boards used by my friends - tempered glass with fruit prints on the back.
It was just a special case. In reality, you can blunt a knife made of the coolest steel if you accidentally touch stones, concrete, or hit hard on bones if the knife is sharpened at a small angle. These 3 little sharpeners helped me out, otherwise it would have taken a lot longer to cook, but I think it makes sense to carry around a diamond board about 6-8 inches (coarse/extra coarse) so that in case of unforeseen circumstances any knife (or Axe) can be sharpened from very dull state more quickly. I think with a large board, sharpening would take 3 times less time than indicated.
Of course, after diamonds on soft steels, a burr sometimes forms and it seems that the knife is very sharp, but it will quickly become dull, so I need Fine India, after it there is no burr on most knives.
And I'm not that crazy now, when I wanted to bring the knife to the state of chopping the hair in limbo, now it is enough to remove the burr and he entered easily into a fingernail most of the length of the blade or cut a newspaper or other similar paper without tearing it.
I like this video, very clearly explained
The last knife here with a serrated Kershaw Random Task 1510ST, steel 440V (now called S60V), I didn't know with using what to sharpen it for a long time, but the edge of the ezelap stone is slightly rounded and has enough diamonds to use it. Result looks scary, but it works and it cuts beautifully.