VII. U.S. Corn Grades and Conversions

corn grades and requirements

U.S. Sample Grade is corn that: (a) Does not meet the requirements for the grades U.S. Nos. 1, 2, 3, 4 or 5; or (b) Contains stones with an aggregate weight in excess of 0.1 percent of the sample weight, two or more pieces of glass, three or more crotalaria seeds (Crotalaria spp.), two or more castor beans (Ricinus communis L.), four or more particles of an unknown foreign substance(s) or a commonly recognized harmful or toxic substance(s), eight or more cockleburs (Xanthium spp.), or similar seeds singly or in combination, or animal filth in excess of 0.20 percent in 1,000 grams; or (c) Has a musty, sour or commercially objectionable foreign odor; or (d) Is heating or otherwise of distinctly low quality.
Source: Code of Federal Regulations, Title 7, Part 810, Subpart D, United States Standards for Corn

metric conversions