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:
“A true politeness does not result from any hasty and artificial polishing, it is true, but grows naturally in characters of the right grain and quality, through a long fronting of men and events, and rubbing on good and bad fortune.”
—Henry David Thoreau (1817–1862)
“The barriers of conventionality have been raised so high, and so strangely cemented by long existence, that the only hope of overthrowing them exists in the union of numbers linked together by common opinion and effort ... the united watchword of thousands would strike at the foundation of the false system and annihilate it.”
—Mme. Ellen Louise Demorest 1824–1898, U.S. women’s magazine editor and woman’s club movement pioneer. Demorest’s Illustrated Monthly and Mirror of Fashions, p. 203 (January 1870)