NMFC Class 50 is the lowest freight class and covers the densest commodities in the LTL system — materials that weigh 50 pounds per cubic foot or more. Think raw construction materials, metals, and heavy industrial goods that fill a trailer by weight rather than by volume. The National Motor Freight Classification (NMFC) system, maintained by the NMFTA, assigns class based on four factors: density, stowability, handling, and liability. Class 50 scores favorably on all four. High density means carriers maximize revenue per trailer. The goods are sturdy enough to withstand normal transit stresses, pose no unusual stacking challenges, and carry low per-unit values that limit theft or total-loss exposure. Because Class 50 represents the least expensive-to-move freight for carriers — and thus the cheapest to ship for shippers — it is the benchmark against which all other classes are measured. A shipper moving pallets of sacked cement or bundled rebar will pay the lowest possible LTL rate per hundredweight. For shippers, correctly classifying dense industrial goods as Class 50 avoids costly freight bill adjustments. Carriers routinely re-weigh and re-measure shipments at origin or destination; a density calculation that falls at or above the 50 lb/cu ft threshold confirms the Class 50 assignment and protects the quoted rate.
Class 50 freight is extremely dense and typically palletized or crated, requiring forklifts or heavy mechanical handling. Individual pieces are rarely hand-moved due to weight per unit.
Stowability: Exceptionally high density makes Class 50 shipments ideal freight from a carrier perspective — they fill trailer capacity by weight long before running out of cubic space. Palletized loads stack well and mix efficiently with other dense freight.
Commodity values are generally low relative to weight, so theft and damage risk are minimal. Proper blocking and bracing prevents shifting, which is the primary damage concern.
Any commodity with a density of 50 pounds per cubic foot or greater qualifies for Class 50 under the NMFC density scale. Common examples include bricks, steel beams, sacked cement, and palletized cast-iron weights.
Class 50 freight is dense, easy to handle, stows efficiently, and has low liability risk. Carriers can fill trailers by weight without wasting cube, which drives down the cost per hundredweight.
Divide the total weight of your shipment (in pounds) by its total cubic footage (length × width × height in inches ÷ 1,728). If the result is 50 or above, the shipment qualifies for Class 50.
Yes. Bagged sand and gravel typically exceed 50 lbs/cu ft when properly palletized and are standard Class 50 commodities. Loose bulk materials moved in tankers or hoppers fall outside LTL freight classification entirely.
Verified 2026-05-26.