The standard strength corrugated boxes can accommodate up to 40lbs of weight per box. They are all ECT32 rated, which is the industry wide accepted rating for shipping boxes. Approved with all the national carriers, they are the recommended box to use for standard shipments. Almost every size combination is available in this box strength and can be found by browsing the items by size and style. With over 1,000 box sizes in stock, you are sure to find the perfect fit.