Shipping "in boxes" means a corrugated or solid fiberboard container (as defined by Item 222 of the NMFC and Rule 41 of the UFC). These are quality standards. These rules give material specifications that vary depending upon the total gross weight and the dimensions of the box and its contents. Boxes that follow the above standards must have a circular box stamp or certificate. Items shipped in cartons with out the proper "box cert" may not be insured by the carrier.
A box, as defined by the carriers, is an enclosure that has at least six sides and has an opening that is only large enough to insert one's fingers to rip open a flap. It must also be capable of passing qualified drop test. Boxes must be made of combined board that meets minimum burst strength and combined basis weight, or the appropriate edge crush test per the appropriate gross weight and dimensions.
