Classification Details
| NMFC | Description | Class |
|---|---|---|
| 55745.00 | Dampers, Louvers or Shutters, NOI, air, fire or smoke, with or without screen cloth backing, in boxes or crates, subject to Item 170 and having a density in pounds per cubic foot of: | |
| 55745.01 | Less than 1 | 400 |
| 55745.02 | 1 but less than 2 | 300 |
| 55745.03 | 2 but less than 4 | 250 |
| 55745.04 | 4 but less than 6 | 175 |
| 55745.05 | 6 but less than 8 | 125 |
| 55745.06 | 8 but less than 10 | 100 |
| 55745.07 | 10 but less than 12 | 92.5 |
| 55745.08 | 12 but less than 15 | 85 |
| 55745.09 | 15 but less than 22.5 | 70 |
| 55745.10 | 22.5 but less than 30 | 65 |
| 55745.11 | 30 but less than 35 | 60 |
| 55745.12 | 35 but less than 50 | 55 |
| 55745.13 | 50 or greater | 50 |
How to Determine Your Class
To find the correct freight class for your shipment:
- Confirm the item fits the scope: air, fire, or smoke dampers, louvers, or shutters (with or without screen cloth), packaged in boxes or crates per Item 170.
- Calculate density from the finished package: pcf = weight (lb) ÷ (L x W x H in inches ÷ 1728). Example: 48 x 24 x 24 box at 120 lb = 120 ÷ 16 = 7.5 pcf; select the matching class within 50-400.
- Immobilize delicate parts. Block and brace blades, lock actuators/links, protect edges and screen cloth, and keep UL fire damper labels visible and upright.
- Choose packaging by size and fragility: sturdy cartons for smaller frames, crating for wide or motorized units. Add moisture barrier and clear orientation and ‘Do Not Stack’ labels.
Note: All classifications are subject to Item 170. Verify with official NMFC publications for the most current requirements.
Business Value
- Density-accurate classing can lower LTL spend—more compact, heavier packs often qualify for lower classes within the 50-400 range.
- Clean paperwork (NMFC 55745, density noted, Item 170) reduces inspection delays, reclass fees, and carrier disputes.
- Right-sized crating and internal bracing cut OS&D claims on blades, jambs, and actuators, preserving margin on HVAC project shipments.
- Non-hazardous status streamlines carrier acceptance and routing, improving pickup reliability and transit options without hazmat surcharges.