NMFC Code for Steel: Freight Class & Lookup

There is no single NMFC code for steel — Steel is among the densest freight there is, so it sits firmly at the cheap end of the scale. Class turns on form factor — bar, rod, and plate are extremely dense, while fabricated or tubular steel can occupy more space per pound. In practice, steel ships across freight classes 50 to 70, with class 60 being a common middle case. To get the exact NMFC item number and class for your shipment, look up steel in the NMFC database or pull it programmatically with the NMFC API.

Steel products classify under provisions keyed to form (bar, sheet, tube, fabricated). Most raw steel forms rate class 50–60 thanks to high density.

Like all LTL freight, steel is classified by the four NMFC transportation characteristics — density, stowability, handling, and liability — but density usually drives the class. Common steel sub-types and how they tend to rate:

• Steel bar, rod, and plate — extremely dense, class 50
• Steel coil and sheet — dense, class 50–55
• Steel cable and wire — class 60
• Fabricated or tubular steel — bulkier, class 60–70

Because the class can swing across this range, the safest approach is to calculate your shipment's actual density and confirm the provision rather than assuming a class. The Freight Class Calculator returns a density-based estimate; Freight Class Explained maps each density band to its class.

Using the correct class for steel directly affects your freight bill and your risk of a reclassification charge:

• Pricing. The class is the single biggest driver of the LTL rate. Guessing low means an underbilled shipment that the carrier later corrects.
• Reclassification fees. If a carrier inspects your steel and finds the class understated, they reclassify it and rebill the difference, often with a fee.
• Documentation. A correct NMFC item number on the bill of lading is your defense in a billing dispute.

See How to Determine Freight Class for the full measure → calculate → confirm workflow.

Because steel spans classes 50–70, it is one of the more frequently reclassified commodities. The errors that cause most steel billing adjustments:

• Defaulting to one class for an entire catalog. The same steel product line can carry several classes depending on size, material, and how it is packaged. A single "house" class applied to everything guarantees some shipments are wrong.
• Measuring the product, not the packaged unit. Class is based on the shipment as tendered — pallet, crating, and overhang included. Measuring only the item understates volume and overstates density.
• Ignoring stowability, handling, and liability. Density is the main driver, but steel can carry a class above its density alone when the provision accounts for these factors.

Run the numbers with the Freight Class Calculator, then confirm against the actual provision — the steps in How to Determine Freight Class catch all three mistakes.

Since density usually drives the class, denser packaging can move steel into a cheaper class and lower the bill:

• Eliminate wasted space. Right-size cartons and remove excess void fill so the packaged unit is as dense as is safe.
• Palletize tightly. A compact, stable pallet configuration with no overhang reduces the cubic footprint that drives the density calculation.
• Ship knocked-down where possible. Flat-packed steel is far denser than assembled, which can mean a materially lower class.

Verify the resulting class before quoting — gains only count if the carrier agrees on inspection. Freight Class Explained shows exactly which density band maps to each class.

Density estimates get you close, but the binding answer is the commodity's actual NMFC provision. Two ways to get it:

• Free lookup: look up steel in the NMFC database by description to see the matching NMFC item and class.
• API: integrate the NMFC API so your TMS or quoting tool resolves the class automatically on every steel shipment.

You can also browse related guidance in our freight classification knowledge base.