Above this, FEPA graded sandpaper becomes increasingly coarser than CAMI graded paper for a given grit size. The CAMI and FEPA scratch patterns are similar for the coarser grits up to 220 grit or so. (There are other standards such as JIS but it is rarely used outside of Japan). If there is a “P” in front of the grit number (ex: P180), the grading system is FEPA. Sandpaper is labeled on the back with the grit size. The “ought” system is an older grading system that is seldom used anymore but included here for sentimental reasons. CAMI is used primarily in North America whereas FEPA is used in Europe and many other parts of the world. CAMI and FEPA are the two most common grading systems in use today. Particles must be smaller than.This chart compares sandpaper grits using three different grading systems: 1) Coated Abrasives manufacturer’s Institute (CAMI), 2) Federation of European Producers Association (FEPA), and 3) the “0” or “ought” grade system. Particles must be larger than and 94% of the This ‘specification’, in the case of JIS R6001 the specification is that forĪny given grit, there is a maximum size, a range of sizes where 50% or more of theĪbrasive particle sizes must conform, and 'bookend' dimensions where greater than 94% of the Of particles above and below this size/range that is accepted as conforming to Is said to match a grit number, and there is a tolerance in size and percentage In most cases, a set size or range of sizes Specification is used to ensure that the abrasive in question 'generallyĬonforms' to a set of dimensions. Small, and it's not possible to measure each one individually, so a 'specification', not an absolute measure. The way in which 'grit' is defined is typically as a * micron, also expressed as μm or micrometre (micro-metre) is one-one millionth of a metre, 0.0000001m, 1.000 × 10 −6 m, 1/1000mm, 39.37 x 10 −6 inch, 0.000039' or in terms we might be able to comprehend, a piece of standard, good quality copy paper is 100 microns thick, human head hair is said to be between 17-150 microns in diameter. The common denominator in this table is the 'stated 'grit' size', which does make labelling easy, but the problem is that grits aint grits! As you will see, for any given grit size, there is no commonality based on the only unchanging measure available to us, abrasive particle size in microns* I have tried to make it as easy to understand as possible, and to try and explain the difference in the abrasive particle sizes in most of the commonly found materials as pertains to 'sharpening'. While it is as all encompassing as is possible, there are limitations to what can be presented in such a table with respect to the amount of data, the way it can be presented and even avoiding 'information overload'. This list of 'grit sizes' is as complete as I can make it with the available information at the present moment in time and from the information provided by manufacturers and standards associations.Īt the time of this compilation, to the best of my knowledge, there is no other table of abrasives and their relative sizes as complete and broad ranging as the one presented above.

Sandpaper grit chart