Freight Class for Steel
Steel is one of the densest things that ships LTL, so under the 2025 density-based scale it sits at the very bottom — class 50 to 60, the cheapest rates on the scale. Here’s the typical range, the math, and the exact class one click away.
The short answer
Typical packaged steel runs about 30–50 PCF, which maps to roughly class 50–60 on the 2025 NMFTA scale. Worked example — a banded bundle of steel bar, 48×40×18 in at 1200 lb:
48×40×18 ÷ 1,728 = 20 ft³ → 1200 ÷ 20 = 60 PCF → Class 50
Why steel classes the way it does
Steel — bar, plate, coil, sheet, tube — is heavy and compact, so a banded bundle or skid carries enormous weight in a small cube. On the 2025 NMFTA scale, which rates on density (pounds per cubic foot), that high density puts steel at the very bottom of the class scale where the rates are lowest, though the sheer weight can bring its own handling considerations.
The band is narrow. Solid bar, plate, and coil are extremely dense and land at class 50. Hollow or thin-wall forms like tube, pipe, or light gauge sheet trap some air and can drift to class 55–60. Loose or oddly stacked steel with big air gaps classes higher — so band the load tightly and calculate from its actual weight and dimensions.
How to calculate it for your shipment
Multiply your packed length, width, and height in inches, divide by 1,728 to get cubic feet, then divide the weight by that volume for density in pounds per cubic foot (PCF). Map the PCF to the class on the NMFTA scale. The Freight Density Calculator does it in one step; the Target Class Calculator runs it backward to find the weight that would hit a class you’re aiming for. Prefer a lookup? The density-to-freight-class chart lists every class and its PCF band.
Get the class right the first time
Because the 2025 scale rates on density, sloppy dimensions are what get steel reclassed and back-billed. Measure to the farthest points on the packed piece, weigh it on a certified scale, and calculate the density before pickup — don’t eyeball the class. For the full picture of how density-based classification works, start with the freight class guide, and see why freight gets reclassed if a carrier disputes your number. Freight class is set by the NMFTA; look up your specific NMFC item with the NMFTA.
Frequently asked
What is the freight class for steel?
Steel typically classes between 50 and 60 under the 2025 density-based scale because it is extremely dense. A banded bundle of steel bar at about 60 PCF classes at 50, the lowest and cheapest class. Hollow tube or thin sheet traps some air and can class 55–60. Calculate the exact class from the load’s weight and dimensions.
Why is steel the cheapest freight class?
Because it is the densest. The 2025 scale rates freight on pounds per cubic foot, and solid steel packs more weight into a cubic foot than almost anything else that ships LTL. Maximum density means the minimum class — class 50 — and the lowest rate per pound.
Do steel tube and pipe class higher than solid bar?
They can. Tube, pipe, and thin-wall sections are hollow, so they trap air and are less dense than solid bar or plate. Under the density-based scale that lower density can move them from class 50 up to class 55 or 60. Nesting and banding tightly keeps the density high.
How do I calculate freight class for steel?
Multiply the bundle or skid length, width, and height in inches and divide by 1,728 for cubic feet. Divide the weight in pounds by that volume to get density in pounds per cubic foot (PCF), then map the PCF to a class on the NMFTA scale. The Freight Density Calculator does it for you.