Packaging standards and specs

This page is the reference layer under the rest of the packaging guide. It is here for two situations: you are designing packaging you will use repeatedly, or you are working through a damage claim and need to know which requirement applies.

Why packaging shows up in classification

The National Motor Freight Classification sorts all freight into 18 classes based on four characteristics: density, handling, stowability, and liability. Packaging feeds directly into three of those four, which is why the classification carries packaging requirements at all.

Each NMFC item number specifies a minimum packaging requirement for the commodity it covers. Those minimums exist so that typical freight is protected well enough to survive normal LTL handling, and so it can be handled and stowed safely. Meeting them is the floor.

There is one alternative route. If a package design does not meet the minimum requirement for its item, it can still be accepted as compliant if it has been certified to pass the performance tests in NMFC Rule 180 or Rule 181. That is a testing exercise rather than a paperwork exercise.

Freight class itself is something we calculate from the weight, dimensions, and commodity you give us. See NMFC Codes and Freight Class.

Classification items that cover packaging

The classification is published by the National Motor Freight Traffic Association at nmfta.org. The exact tables and text are their copyrighted material, so we do not reproduce them here. Your box or packaging supplier can also tell you which requirement applies to what they are selling you.

Box size and weight limits

NMFC Item 222 sets the maximum weight and maximum combined dimensions for each fiberboard construction, matched to a minimum strength rating. The strength rating is expressed either as a bursting test value paired with a minimum combined weight of facings, or as an edge crush test (ECT) value.

To give a sense of the range those tables cover:

• Single-wall corrugated tops out at around 120 lb of box and contents, with combined length, width, and depth of roughly 105 inches.
• Double-wall corrugated extends to around 180 lb and roughly 120 inches combined.
• Triple-wall corrugated extends to around 300 lb and roughly 125 inches combined.
• Solid fiberboard tops out at around 120 lb and roughly 100 inches combined.
• There are exceptions allowing greater weights and lengths for long freight. Those are worth asking about rather than assuming.

Every box carries its own limits on its certificate stamp, and that stamp is the version that matters for the box in front of you. See Boxes and cushioning for how to read it.

Test methods worth knowing by name

ASTM standards are available from astm.org and ISTA procedures from ista.org.

Measuring containment force. If you want to check that your stretch wrapping is actually doing something, ASTM D4649 Section A1.10 describes the pull plate method. Place a 6 inch diameter plate behind the film on the long side of the load, 18 inches across and 10 inches down from an upper corner, then record the force in pounds needed to pull the plate out 4 inches. Equipment makers sell kits and tools for this.

Wood specifications

• Softwood grade: #3 Standard or better. Do not use #4 Utility, also sold as Economy, or below.
• Hardwood grade: #3A Common or better. Do not use #3B Common or below.
• Moisture content: under 20 percent, to prevent mold.
• Knots: NMFC Item 245 prohibits lumber with knots exceeding one third of the width of the wood.
• Plywood and OSB: APA certified Structural 1 rated sheathing for cross-panel strength, and Exterior or Exposure 1 grade for moisture resistance. Span ratings, open spans, and fastening patterns are in the APA Engineered Wood Construction Guide (E30) at [apawood.org](https://www.apawood.org).

Fastener specifications

Two general rules apply to all of them. Fasteners are not designed to carry shear force, so a joint loaded sideways needs the geometry to take the load rather than the fastener. And end grain fastening has very little holding capability, so fasten into side or edge grain wherever you have the choice.

Equipment your freight has to fit

Trailer door openings, lift gate platforms, fork tine dimensions, and pallet jack widths all vary between carriers and between pieces of equipment at the same carrier, so there is no single set of numbers that is safe to design against. Two things are consistent:

• Dock staff need clearance to work. Freight sized right up to the trailer opening cannot be moved in and out without damage.
• Lift gates have both a platform size limit and a weight limit. Freight that exceeds either one cannot be delivered that way, which usually means a refused or delayed delivery. See Lift Gate Required.

If you are shipping something unusually large, tell us the dimensions and we will confirm what is workable before you book rather than after.

Getting a design evaluated

If you ship the same thing repeatedly, having the packaging evaluated once is worth far more than reacting to claims one at a time.

• Test it in an accredited laboratory. Laboratories accredited by ISTA, ASTM, or registered with the Commodity Classification Standards Board will run your package through a standard sequence. Testing will not reveal every possible failure, but it reliably exposes the obvious weaknesses before your customers do.
• Talk to a packaging engineer. They design and validate packaging systems for a living, and they usually reduce material cost at the same time as reducing damage.
• Ask your suppliers for the data. Cushion curves from your foam supplier, stretch percentages from your film supplier, and application recommendations from your strapping supplier are all free and all specific to the material you are actually using.