Determines how efficient a grinding wheel is at removing material from the tool being sharpened. A higher degree of material removal means that the grinding wheel is more efficient at removing material, and so repairing or reshaping an edge will go faster.

Determines how finely polished the sharpened surface gets from the grinding wheel. A higher score in the Polishing / Finish category means that the grinding wheel provides a higher degree of polished finish on the tool after sharpening, and less "scratch marks" are left from sharpening. A high score in this category category is desirable on tools for fine woodcarving, or other applications where you require an extremely smooth cut. Or if you want a mirror finish for an enhanced visual appearance.

Determines how well suited the grinding wheel is for sharpening common tool steels, often used in hand tools. A higher score in this category means that the grinding wheel is better suited for sharpening common tool steels.

Determines how efficient the grinding wheel is at sharpening HSS, exotic alloy steels, tungsten carbides or other hard metals, often used in wood turning tools and specialized knives. A higher score in this category means that the grinding wheel provides a more efficient sharpening of such hard metals.

Defines if the grinding wheel is able to sharpen ceramic or not, like ceramic knives for example. Since ceramics generally are such hard and brittle materials, only certain abrasives can sharpen it.

Defines whether a grinding wheel keeps its exact shape over time or not.

A diamond grinding wheel will never go out of true or in any way lose its shape, as long as it is handled and used correctly. This makes setting up sharpening easier as you can always keep the same settings even after switching between different diamond grinding wheels.

A grindstone will go out of true and lose its shape over time and regular use, and require truing. This makes it reparable if it has minor damages.

Defines if the grinding wheel is compatible with the SP-650 Stone Grader or not. The stone grader is used to adjust the characteristics of certain grindstones for a coarser or finer surface.

Note that the stone grader should never be used on a diamond grinding wheel, as it will destroy the diamond coating and render the diamond grinding wheel useless.

Also note that the the fine side of the stone grader can be used to clean up the Japanese Waterstones. However, it cannot be used to adjust the grit characteristics of the Japanese Waterstones and you should never use the coarse side of the stone grader for these grindstones.

Defines if the grinding wheel is compatible with the TT-50 Truing Tool or not. The truing tool is used to true a grindstone that has gone out of shape and needs to become completely round again.

Note that the truing tool should never be used on a diamond grinding wheel, as it will destroy the diamond coating and render the diamond grinding wheel useless.