Pallet types
Block pallet: how it's built and when it beats a stringer pallet
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A block pallet is a wood pallet whose deck is carried on blocks, typically nine in a 3 x 3 grid, connected by stringerboards instead of continuous stringers. The open space between blocks gives full four-way fork entry, which is why pooled pallets and the 1200 x 800 mm EPAL Euro pallet are block pallets.
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What is a block pallet?
A block pallet is the block-class pallet in the Uniform Standard. Instead of two or three continuous stringers, the top deck sits on stringerboards that are nailed down onto blocks, usually nine arranged three by three. Because nothing runs continuously under the deck in either direction except at the blocks, forks can enter from all four sides: full four-way entry.
How a block pallet is built
From top to bottom, a block pallet has five layers:
| Layer | What it is | Typical size |
|---|---|---|
| Top deckboards | Boards across the stringerboards | 5/8 to 3/4 in thick, 3-1/2 to 5-1/2 in wide |
| Stringerboards | Three full-length boards, one over each block row | About 3/4 x 5-1/2 in on a 48 x 40; 22 x 145 mm on an EPAL 1 |
| Blocks | Spacers that create the fork openings | Solid wood, laminated or presswood blocks; 78 mm tall on an EPAL 1 |
| Bottom stringerboards or boards | The base, in one of several patterns | Same stock as the top |
| Fasteners | Separate schedules for mat, top-to-block and bottom-to-block joints | See below |
The top deckboards and stringerboards are often pre-assembled into a deck mat with clinched nails, then nailed through into the blocks. One published anatomy describes 3 in annular nails through the stringerboard into the block, 1-5/8 in smooth mat nails and 2-1/4 in annular bottom nails. The Uniform Standard sets a minimum of 3 fasteners at each corner block and 2 at each interior block.
palletdesign.ai's starting 48 x 40 block template uses 3/4 in decks, 5-1/2 in stringerboards and 5-1/2 x 5-1/2 x 3-1/2 in blocks; every dimension is editable.
Bottom deck styles
- Perimeter base: boards on all four sides, like a picture frame. See perimeter base pallets.
- Unidirectional base: bottom boards in one direction only, so pallet-jack wheels can drop to the floor between them from the sides.
- Cruciform base: a perimeter plus center boards in both directions.
When to use a block pallet
- Four-way handling with forklifts and pallet jacks in busy warehouses.
- Pooled systems and retailers that require them: Costco requires pooled block pallets and accepts purpose-built pallets only by exception.
- European and international shipping, where the Euro pallet and CP pallets are block designs.
- Automated handling, where a perimeter or cruciform base is commonly specified so the pallet bears on a frame in both directions.
When not to use one
- Low-cost one-way shipments, where a stringer pallet uses fewer parts and less labor.
- Very long or odd sizes. Stringer pallets scale more simply.
- Rack storage with heavy loads, unless the design has been checked. Racked, a block pallet relies on the stiffness of its deckboards and stringerboards; confirm the rating with a PDS analysis or a physical test.
Block pallet vs stringer pallet
| Block pallet | Stringer pallet | |
|---|---|---|
| Entry | Full 4-way | 2-way or partial 4-way |
| Pallet jack from sides | Yes with a unidirectional base | No |
| Part count | Higher (blocks, stringerboards, mat) | Lower |
| Cost to build | Higher | Lower |
| Common sizes | 48 x 40 block, 1200 x 800, 1200 x 1000 | 48 x 40 stringer and most custom sizes |
How to specify a block pallet
- Size and which way the top deckboards run (across the width in North America, along the length on an EPAL 1).
- Top deckboards: count, thickness, widths.
- Stringerboards: thickness and width.
- Blocks: width x length x height, material (solid, laminated or composite), grain orientation.
- Bottom style: perimeter, unidirectional or cruciform, with board sizes.
- Fasteners for each connection: mat, top-to-block, bottom-to-block.
- Lumber species, grade, moisture; heat treatment if exported.
- Load, support conditions and handling equipment.
Capacity on a block pallet depends heavily on support condition. Any figure should come with its support stated, and a certified rating comes from the manufacturer's Pallet Design System analysis or testing to ISO 8611 or ASTM D1185.
Questions
- How many blocks are in a block pallet?
- Nine is standard, in three rows of three. Some designs add or delete blocks, and the Pallet Design System supports custom block counts and sizes.
- Are block pallets stronger than stringer pallets?
- Not automatically. Capacity depends on the support condition: racked, a block pallet relies on its deckboards and stringerboards, while a stringer pallet racked across its length relies on its stringers. Compare designs condition by condition.
- Why are pooled pallets block pallets?
- Pooled pallets travel through many different warehouses, so they need four-way fork and pallet-jack access and a long service life. The block design delivers both.
- Can a pallet jack enter a block pallet from the side?
- Yes if the bottom boards run in one direction (a unidirectional base) so the wheels can reach the floor between them. With a perimeter base, check the wheel openings for the direction the jack enters.