Auto parts are one of the higher-error categories for NMFC classification in LTL freight, simply because the parts are so varied. "Auto parts" as a label covers fuel pumps, filters, mufflers, and body parts — each with its own distinct code — and most of these codes split into 13 density tiers, with class potentially landing anywhere from 50 to 400 depending on measured density. A commodity description that just says "auto parts" is effectively no description at all — the carrier can't classify it accurately, and it's very likely to get reclassified after pickup.
What to watch for when classifying auto parts
"Auto parts" isn't one code — it's dozens
Fuel pumps or fuel pump assemblies (NMFC 127645), filters (NMFC 69100), mufflers/exhaust systems (NMFC 125850), radiator/fuel tank/oil filler caps (NMFC 116435), and steering assemblies (NMFC 24520) are each independent codes. Describe the specific part so the right code can be found — a generic "auto parts" or "car parts" label won't match anything specific, leaving only a rough density estimate, which carries real risk of a classification error.
Body parts split by density, and the class spread is meaningful
Automobile body parts (NMFC 18260) splits into 13 density tiers, with class potentially landing anywhere from 50 to 400. Two shipments both labeled "body parts" can calculate to very different densities depending on packaging and the actual space occupied — and that translates directly into a meaningful difference in freight cost.
Vehicle-like products — go-karts, for example — don't belong in "general toys"
Go-karts and children's cars (NMFC 190220) fall under a vehicles-related code, also density-tiered across the same full range — not the same code as ordinary body parts. These products are easy to mislabel as a generic "toy," but they have a dedicated code, and using the wrong commodity category leads directly to a classification error.
Example auto parts NMFC codes
The codes below are verified against ShipMay's own NMFC database and are meant to illustrate classification logic — the exact code and class that applies to your shipment depends on your actual commodity description, measured density, and the carrier's own review:
| Commodity | NMFC Code | Typical Class Range |
|---|---|---|
| Fuel pumps or fuel pump assemblies | 127645 | 50 – 400 (13 density tiers) |
| Filters (air, oil, etc.) | 69100 | 50 – 400 (13 density tiers) |
| Mufflers, exhaust systems, catalytic converters | 125850 | 50 – 400 (13 density tiers) |
| Radiator/fuel tank/oil filler caps | 116435 | 50 – 400 (13 density tiers) |
| Steering assemblies | 24520 | 85 |
| Automobile body parts (NOI) | 18260 | 50 – 400 (13 density tiers) |
| Go-karts / children's cars | 190220 | 50 – 400 (13 density tiers) |
How to find the code that actually applies to your shipment
For auto parts, confirm each part type individually: search by the specific part name — fuel pump, filter, muffler — rather than "auto parts" in the NMFC Lookup tool; for mixed boxes with several part types, identify the dominant item by weight or volume; and measure actual density carefully, since the same part can pack very differently depending on packaging. When in doubt, send ShipMay the commodity, weight, and dimensions — the final code and class are still subject to the carrier's own review.
Common mistakes
- Using "auto parts" as the entire commodity description — the category is too varied for a generic label to map to an accurate code.
- Assuming similar parts all share one class — many auto parts codes are density-tiered, so the same part at a different density gets a different class.
- Labeling go-karts or ride-on toys as general toys — these vehicle-like products have a dedicated code and shouldn't be filed under generic toys.
Related reading
- Free NMFC code lookup
- Freight class calculator
- LTL Reweigh and Reclass: Why Freight Bills Change After Pickup
- A complete guide to U.S. freight accessorial charges
- LTL freight quotes and multi-carrier rating
- Truckload shipping
NMFC code guides for other common commodity categories: electronics, furniture and glassware, food and packaging, building materials and metal.
Sources
- National Motor Freight Traffic Association (NMFTA), which develops and maintains the NMFC classification standard.
- The specific codes, descriptions, and class ranges listed above are verified against ShipMay's own NMFC database and are illustrative of classification logic only — they don't replace the carrier's own review at time of shipment.
