Grain Numbers
Grain numbers define the size of the grain. The number corresponds to the number of meshes per linear inch in the grading sieve. Common numbers are, from coarse to fine: 10, 12, 14, 16, 18, 20, 24, 30, 36, 40, 46, 54, 60, 70, 80, 90, 100, 120, 150, 180, and 200. Grains finer than 200 are known as "flour" and are designated by the letters: CF, F, FF, FFF, FFFF, and PCF or SF (coarse to fine). Note that the grades for flour are not standardized, so the same grade grains from different sources may differ in size slightly.
Read more about this topic: Emery (mineral)
Famous quotes containing the words grain and/or numbers:
“He showed me that the lines of a good helve
Were native to the grain before the knife
Expressed them, and its curves were no false curves
Put on it from without.”
—Robert Frost (1874–1963)
“I had but three chairs in my house; one for solitude, two for friendship; three for society. When visitors came in larger and unexpected numbers there was but the third chair for them all, but they generally economized the room by standing up.”
—Henry David Thoreau (1817–1862)