An organization named the National Motor Freight Traffic Association (NMFTA) publishes a list of freight class designations, codes, and subclasses for frequently shipped commodities (https://classit.nmfta.org/). You must pay a subscription fee to view it. Find more information about freight classes from the experts at Koho for free on our freight classes pages.
It might be tempting to declare that your shipment is a lower freight class than it actually is in order to secure a lower price, however, carriers will re-classify your freight for accuracy and charge you a fee for having to do so.
NMFC freight classes are determined using four factors: density, handling, stowability, and liability. All of these factors affect the cost to the carrier of shipping goods.