Two tiers on the scale: 175 and 125
On the NMFC 13-tier density scale, Sub 4 covers 4 to under 6 PCF and rates class 175. Sub 5 covers 6 to under 8 PCF and rates class 125. Freight in this band is the backbone of commercial LTL: assembled cabinets, medical and utility carts, store fixtures, small appliances, boxed furniture and pumps in light crates.
| Sub | Class | Density | Weight on a 48×40×48 pallet | Weight on a 48×40×60 pallet | Typical freight |
|---|---|---|---|---|---|
| 4 | 175 | 4 to under 6 PCF | 214 to 319 lbs | 267 to 399 lbs | Assembled office casework, medical carts, refrigeration shells |
| 5 | 125 | 6 to under 8 PCF | 320 to 426 lbs | 400 to 533 lbs | Vending machines, range hoods, small crated pumps, boxed fixtures |
A 48 × 40 × 48 pallet is 53.33 cubic feet and a 48 × 40 × 60 pallet is 66.67 cubic feet, which is where those weight windows come from. Moving one class in this band, from 175 to 125, cuts the class factor by nearly 30 percent, which on most carriers' base rate tables is one of the larger steps on the scale.
Where class 150 went, and why you still see it
The density scale goes straight from class 175 to class 125. There is no subprovision that produces class 150, and that was true of the older 11-tier scale too. Yet class 150 shows up on plenty of bills of lading. There are two reasons.
- Commodity-specific NMFC items. The NMFC still uses 18 classes in total, and class 150 is one of them. Some commodity items carry class 150 as a fixed class or as one of their own density breaks, reflecting handling or liability characteristics, not density alone. If your product's item assigns class 150, that item governs, not the general scale.
- Legacy pricing agreements. Many FAK (freight all kinds) clauses were written years ago with bands such as "actual class 125 to 175, rate as 150". The freight is still classed by density; the agreement simply rates it at 150. When the carrier reclassifies the freight on a W&I inspection, the FAK band decides what you pay, and the cube rule may decide whether the FAK applies at all, as explained on the FAK exceptions page.
The practical rule: if your freight is classed by density, write the density class (175 or 125) on the bill, and let your pricing agreement translate it. Do not write 150 because a routing guide from a previous year says so. A class on the BOL that the dimensions do not support is a reclassification waiting to happen.
The 6 PCF line does double duty
Six pounds per cubic foot is the boundary between class 175 and class 125. It is also the density ceiling of the Tier 2 cubic capacity rule that every major LTL carrier publishes: 750 cubic feet or more at under 6 PCF, as in Old Dominion's ODFL 100 Item 610-1 and XPO's CNWY 199 Item 233.
That makes 6 PCF the single most valuable line on the scale for bulky freight. Below it, a shipment is class 175 and, if it grows past 750 cubic feet of tariff cube, exposed to a synthetic weight of 6 lbs per cubic foot and a discount that may not apply. At or above it, the shipment is class 125 and the Tier 2 rule cannot apply on density grounds. One repack can win both.
Remember that the carrier measures tariff cube, not physical cube. Non-stackable units and units over about 60 inches are cubed at 96 inches, so a load that is 6.3 PCF on its real dimensions can fall to 4 PCF on tariff cube. Height and stackability are as important as weight in this band.
Find the 6 PCF line for your load
- Safe — tariff cube, density and linear feet stay under the carrier's cube and linear-foot rules.
- Tier 1 — 350 cu ft or more under 3 PCF (XPO, Saia, ABF, Estes): synthetic weight of 6 lbs per tariff cubic foot.
- Re-bill — 750 cu ft or more under 6 PCF, or linear feet at the carrier's rule: book volume LTL or direct partial truckload.
Worked example: eight pallets of steel carts, repacked
A fabricator ships eight stackable 48 × 40 pallets of knock-down utility carts. As built today each pallet is 56 inches tall and weighs 320 lbs.
| Build | Cube per pallet | Total cube | Weight | Density | Class | Linear feet |
|---|---|---|---|---|---|---|
| As built, 56 in | 62.22 cu ft | 497.8 cu ft | 2,560 lbs | 5.14 PCF | 175 | 16 LF |
| Repacked, 48 in | 53.33 cu ft | 426.7 cu ft | 2,560 lbs | 6.00 PCF | 125 | 8 LF |
| Repacked, 46 in | 51.11 cu ft | 408.9 cu ft | 2,560 lbs | 6.26 PCF | 125 | 8 LF |
The math: 48 × 40 × 56 ÷ 1,728 = 62.22 cubic feet per pallet, times eight is 497.8; 2,560 ÷ 497.8 = 5.14 PCF. At 56 inches two pallets will not fit one above the other under a 96-inch ceiling, so the eight pallets sit in four rows of two, 4 × 48 ÷ 12 = 16 linear feet, past the 12 to 15 foot linear rules carriers publish.
Repacking to 48 inches by laying the cart frames flat brings the load to exactly 6.00 PCF: class 125 on paper, but with no margin. A dimensioner that reads 48.5 inches puts it back at 5.94 PCF and class 175. At 46 inches the load is 6.26 PCF, safely class 125, and the pallets can now be double-stacked (46 + 46 = 92 inches), so they occupy two rows and 8 linear feet.
On our indicative model for an 800-mile lane, the 56-inch build costs about $721 at class 175 before any linear-foot charge, and about $846 once the 16-foot length triggers the linear rule. The 46-inch build rates about $515 at class 125. Those are planning figures; the shape of the saving is what to take to your packaging team.
Packaging moves that work in the 4 to 8 PCF band
- Lay it flat. Frames, panels and doors shipped flat rather than upright often lose 8 to 12 inches of height per pallet.
- Get under 60 inches and make the top flat. Under 60 inches with a load-bearing top, the carrier cubes your real height and can double-stack the pallet. Over 60 inches, expect a 96-inch imputation.
- Match the pallet to the product. A 48 × 48 pallet under a 48 × 40 load adds 2.67 cubic feet per foot of height for nothing. Use the smallest deck the product sits on safely.
- Remove overhang. One inch per side on a 60-inch pallet adds 6.25 cubic feet. On a pallet sitting near 6 PCF that is a class.
- Build for the tier you need. Use the weight windows above: at 48 inches, a 48 × 40 pallet needs 320 lbs to be class 125. If a pallet is consistently at 300 lbs, add product from the next order rather than ship a light pallet.
The overhang and packaging guide gives the numbers for each of these.
When the mode matters more than the class
Bulky commercial freight in this band often moves in 6 to 14 pallet lots: a cabinet order for one building, a fixture rollout for one store. At that size the class is no longer the whole story. Eight pallets at 16 linear feet are already in the zone where carriers apply linear-foot rules and where a spot volume LTL quote or a direct partial truckload, both priced on space and weight rather than class, usually win.
Our desk rule for 4 to 8 PCF freight: under 300 cubic feet, fix the class and ship class-rated LTL. Between 300 and 750 cubic feet, fix the class and price volume LTL alongside it. Over 750 cubic feet, or over 12 linear feet, price direct partial truckload first, especially for finished goods like cabinetry where one forklift tine through a door panel costs more than the freight. Send the load to rates@cubictransport.com and we will price the options together.
