An organization called the National Motor Freight Traffic Association (NMFTA) publishes a list of freight class designations, codes, and subclasses for many frequently shipped items (https://classit.nmfta.org/). To view this list, you must pay a subscription fee. Learn more about freight classes from the experts at Koho for free on our freight classes pages.
The National Motor Freight and Traffic Association has 18 freight classes numbered 50 to 500. The lower the freight class, the lower the cost of transporting that freight.
NOI stands for Not Otherwise Indicated. This is used when a commodity does not have an NMFC code. In these cases, density is usually used to determine freight class.