![]() It has a specified percentage of 8k particles.Īnother thing to consider is particle shape, density, and material.Īlox does not cut like FeOx, and diamond does not cut like either of them. The proportion of the 8k particles to the non-8k particles is critical in particular - the percentage of larger to smaller and so on.Įssentially - an 8k stones is not 100% 8k abrasive. On top of that - the stone has 8k particles - but it also has particles that are larger and smaller. But they don't tell you what scale they used. Comparing one particle's size to another is futile unless they were both measured against the same scale. The scale used to qualify that particle's size is key. It suggests that there is a particle, and that it has a size. Microns are a universally accepted measurement - used for lots of things, particle sizes included. Mesh is one scale or standard for specifying the sizes of particles. 5 micron or about 30K grit finishing abrasives and it is now not uncommon to use sub- 0.1 micron abrasives, usually diamond or CBN (cubic boron nitride), both of which are extremely hard, sharp and cut quickly for a given particle size. Just as an example, you can shave with a razor honed on 8,000 grit stones or 3 micron film (about the same) but the blade is a bit coarse yet. If you poke around on the 'Net a little, you will find conversion charts for all of these measuring and rating systems. The Japanese seem to rate abrasives as coarser than they really are by some amount a 10K Japanese stone seems more like a 14K non Japanese stone for example. There are direct conversions as already printed for lapping film. So as the abrasive gets finer, the grit rating goes up (220 grit sandpaper is finer than 100 grit sandpaper) but the micron rating goes down (1 micron film is finer than 3 micron film). The difference is that this measurement is metric and measures the particle size itself rather than how many particles will fit in a certain length. Micron: the size of the individual grit particle, like the grit rating above. Also note that sieved grit can and will contain grit smaller than the actual mesh rating. The problem with this method is that the wire size is sometimes considered 1,000 mesh may mean that each mesh opening is 1/1000 of an inch or it may mean there are 1,000 wires per inch in which case the actual openings in the mesh will be 0.001" minus two wire diamters. If you have a 1,000 mesh, it usually means there are 1,000 wires per inch at 90 degrees to each other, as a window screen is. Mesh: is the size of the mesh that separated the grit below from the grit above. ![]() So for a 1,000 grit abrasive, each little stone is 1/1000th of an inch in 'diameter' (not really round but they take up the volume of 0.001 inch). Grit: is the size of the individual particle. ![]() Those are all standard terms and methods. ![]()
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