Nestable, rackable and stackable describe how a pallet is built and where it can safely carry a load. A nestable pallet has legs that slot into the pallet below it to save space when empty, a stackable pallet can carry another loaded pallet on top of it, and a rackable pallet is stiff enough to span the open gap between two rack beams while loaded.
Three design families, three load cases
The three terms are often used as if they were product grades, but they really describe the load case a pallet is designed to survive. Every pallet supports weight in three basic situations, and the design determines which of them it can handle:
- Static load: the pallet sits on a flat, solid floor, often at the bottom of a stack of loaded pallets.
- Dynamic load: the pallet is lifted and moved by a forklift or pallet truck, so the load is carried on forks and subject to acceleration and braking.
- Racking load: the pallet rests only on its edges or runners across two beams, with nothing supporting the middle.
The racking case is almost always the most demanding because the deck must act as a beam. The detail behind these numbers is covered in static, dynamic and racking load ratings.
| Design | Typical base | Empty storage | Static | Dynamic | Racking |
|---|---|---|---|---|---|
| Nestable | Nine feet (legs), no bottom deck | Nests into the pallet below | Moderate | Moderate | Usually not rated |
| Stackable | Runners or a full bottom deck | Stacks flat | High | High | Limited or not rated |
| Rackable | Perimeter base or runners, often reinforced | Stacks flat | High | High | Rated for open-span beams |
Nestable pallets
A nestable pallet has a top deck with nine hollow, tapered feet underneath. When empty, the feet of one pallet drop into the feet of the pallet below, so a stack of nested pallets is far lower than a stack of flat pallets. This is why nestable designs dominate in one-way shipping and in return flows where empty pallets travel back in a truck: more empties fit in the same trailer, which lowers the cost of every return trip.
The trade-off is structural. Without a bottom deck, the load is concentrated through the nine feet, so nestable pallets cannot usually sit across rack beams and are poorly suited to conveyors and stacking several loaded pallets high. Most are made of plastic (typically high-density polyethylene, HDPE, or polypropylene, PP), but moulded wood fibre pallets also nest; see presswood (moulded wood) pallets.
Good fit: export shipments that will not come back, light to medium loads, floor storage, picking areas, and closed loops where empties travel long distances.
Stackable pallets
A stackable pallet has runners (usually three) or a full perimeter bottom deck that spreads the load evenly onto the pallet below. This lets loaded pallets be block-stacked on the floor, which is the main way many warehouses store goods without racking. Empty stackable pallets stack flat rather than nesting, so they take more space on return trips than nestable designs.
Many standard wooden pallets, including the EPAL Euro pallet, are stackable by construction. EPAL states that when laden Euro pallets are stacked on a solid, even surface, the bottom pallet must not carry more than 5,500 kg in total, while the safe working load on a single pallet is 1,500 kg. Safe stack height in practice depends just as much on the goods and the packaging as on the pallet itself; see pallet stacking rules.
Good fit: block-stacked warehouses, beverage and bulk products, shipments where the receiver double-stacks pallets in trucks.
Rackable pallets
A rackable pallet is designed to carry its load while supported only along two edges, either across the depth of a selective pallet rack (the usual orientation) or across its width. To do this without excessive sag, plastic rackable pallets are thicker and are often reinforced with steel tubes or glass-fibre profiles moulded into the deck or runners. Wooden rackable pallets rely on adequate board thickness, spacing and fastening.
The key performance criterion is deflection: how far the pallet bends under load between the beams. Too much deflection can push a load off-square, catch on the beam during retrieval or, in the worst case, lead to collapse. For this reason rackable pallets are usually given a separate, lower racking rating than their static rating, and the rating is only valid for a stated rack orientation and beam span. For rack design and pallet orientation, see pallet racking systems.
Good fit: selective, drive-in and push-back racks, automated storage and retrieval systems, and any warehouse where pallets live on beams for weeks or months.
How the ratings are tested
Load ratings published by manufacturers are only comparable when they are measured the same way. The international reference is ISO 8611, which is published in three parts:
- ISO 8611-1: test methods for flat pallets, including bending, compression, shear and drop tests.
- ISO 8611-2: performance requirements and selection of tests.
- ISO 8611-3: maximum working loads.
In Europe, EN 13698 covers production specifications for wooden pallets, and in North America ASTM D1185 and ANSI MH1 are widely used. Two points matter to buyers. First, ratings normally assume a uniformly distributed load; a point load or a load concentrated in a small area lowers the safe capacity sharply. Second, plastic deforms slowly over time under constant load (creep) and becomes weaker at high temperatures, so plastic pallets are tested for duration and often rated at a stated temperature. A detailed comparison of test standards is in pallet testing standards.
Choosing between the three
Start with the most demanding place the pallet will ever be, not the most common. A pallet that spends 95% of its life on the floor but is occasionally placed in a rack must be rated for racking.
- Will it go into racks? If yes, specify a rackable pallet with a racking rating that covers the load, the rack orientation and the beam span.
- Will loaded pallets be stacked? If yes, the pallet needs a bottom deck or runners and a static rating covering the total weight of the stack.
- How do empties return? If empties travel long distances or the pallet is one-way, nestable designs cut return freight. In a pooled or exchange system, the pool's standard pallet decides the question for you.
- Which handling equipment? Hand pallet trucks need openings in the bottom deck for their wheels. Nestable pallets and many runner designs accept pallet trucks from limited directions, so check entry on all sides.
- What do conveyors or automated systems require? Conveyors generally need flat, continuous runners or a perimeter base; nine-foot nestable pallets rarely run on roller conveyors.
The broader decision, including hygiene, export rules and cost per trip, is covered in how to choose a pallet.
Frequently asked questions
Can a nestable pallet be used in pallet racking?
Generally no. Nestable pallets have nine feet and no bottom deck, so they are not designed to span between rack beams. A few heavy nestable designs are offered with a racking rating, but only for specific rack configurations stated by the manufacturer.
Is every stackable pallet also rackable?
No. Stacking puts the pallet on a fully supported surface, while racking leaves the middle unsupported. A pallet can be strong in a block stack but sag too much across open beams.
Why is the racking rating lower than the static rating?
In racking, the deck works as a beam supported only at its edges, so bending stress and deflection are much higher than when the pallet sits on a flat floor. The racking rating also depends on beam span and orientation.
Which standard should load ratings refer to?
Ask for ratings measured to ISO 8611 or an equivalent recognised standard such as ASTM D1185, and check whether the figure assumes a uniformly distributed load, a temperature and a rack orientation.
Sources
- EPAL Euro pallet: technical data — European Pallet Association (EPAL)
- EPAL 6 half pallet: technical data — European Pallet Association (EPAL)
- Pallet — Wikipedia
- EUR-pallet — Wikipedia