Joint (pallet connection)
Also called: connection, nailed joint, fastener joint
A joint is the fastened connection where a deckboard or stringerboard crosses a stringer or block. Its strength depends on the number and type of fasteners, the wood density and the moisture content.
In depth: Pallet nails and fasteners: types, sizes, MIBANT and nail counts
A GMA-style 48 × 40 has 7 top boards and 5 bottom boards crossing 3 stringers, so it has 21 top joints and 15 bottom joints. Each joint holds 2 or 3 nails, for 84 in total.
Minimum fasteners per joint (Uniform Standard, 2012, Table 5)
| Deckboard width | Minimum fasteners |
|---|---|
| Up to 5-1/4 in (133 mm) | 2 |
| 5-1/4 to 7 in (133 to 178 mm) | 3 |
| 7 to 8 in (178 to 203 mm) | 4 |
| Block pallet, corner block | 3 |
| Block pallet, interior block | 2 |
Penetration into the stringer or block should be at least 1-1/4 in (32 mm), or 1 in where the deck is 1/2 in thick or less.
Why it matters
Most pallets wear out at the joints. Forks and pallet jacks knock boards loose, nails withdraw as wood dries, and heads pull through thin boards. Joint strength depends on fastener type (helical or annular nails hold much better than plain shank), wire stiffness (MIBANT), wood density and moisture content. Since PDS 5.3, a connection can be the "critical member" in a structural analysis.
On a spec sheet
The fastener table gives the fastener specification per connection type. The deck tables give fasteners per connection per board, and the drawings show nail positions as dots. See nailing pattern.
Related
- GlossaryNailing pattern (pallet)A nailing pattern is the number and position of fasteners at each joint of a pallet. The Uniform Standard sets minimums by deckboard width: 2 fasteners per joint for boards up to 5-1/4 in wide and 3 for 5-1/4 to 7 in.
- GlossaryNail (pallet fastener)A nail is the standard fastener for wood pallets, driven through deckboards into stringers or blocks. Pallet nails are specified by shank type (helical, annular or plain), length, wire diameter, head diameter and bending strength.
- GlossaryHelically threaded nail (pallet)A helically threaded nail has spiral flutes rolled into its shank so it rotates as it is driven, which locks it into the wood. It is the most common pallet nail, recommended for medium- and high-density hardwoods.
- GuidesPallet nails and fasteners: types, sizes, MIBANT and nail countsMost wood pallets use threaded nails: helical (screw shank) for dense hardwoods, annular (ring shank) for softwoods. A typical deck nail is 2-1/4 in long with 0.112–0.120 in (11.5–11 gauge) wire. The Uniform Standard requires at least 2 nails per joint on boards up to 5-1/4 in wide and 3 on wider ones.
- StandardsUniform Standard for Wood Pallets (Woodpack Global, formerly NWPCA)The Uniform Standard for Wood Pallets is the North American industry standard for specifying, building and repairing wood pallets: terms, lumber quality, tolerances, fasteners, notches, repair and performance. Woodpack Global (formerly NWPCA) publishes it; it is voluntary and was revised in 2025.
More in Components and construction
- GlossaryActual dimension (pallet and lumber)An actual dimension is the measured size of a pallet or component at manufacture. Pallet spec sheets state component sizes as actual dimensions, for example a 5/8 × 3-1/2 × 40 in deckboard.
- GlossaryBlock (pallet)A block is a rectangular, square or cylindrical spacer between the decks of a block pallet. Most block pallets have 9 blocks in a 3 × 3 grid, and the block height sets the fork entry height.
- GlossaryBottom deck (pallet)The bottom deck is the lower layer of deckboards (or a perimeter, runner or panel base) on a double-face pallet. It spreads the load onto the floor, rack or conveyor and stabilizes the stringers or blocks.
- GlossaryBottom deck coverage (pallet)Bottom deck coverage is the percentage of a pallet's underside covered by bottom deckboards. A GMA-style 48 × 40 bottom deck covers about 45%, less than the top deck, to leave room for notches and pallet-jack wheels.
- GlossaryCenter block (block pallet)The center block is the middle block in the 3 × 3 grid of a nine-block pallet. It supports the middle of the deck and, on EPAL pallets, carries the producer, date and treatment marks.
- GlossaryChamfer (pallet)A chamfer is a bevel cut along the edge of a bottom deckboard, usually a lead board, so pallet-jack wheels can ride up and over it instead of hitting a square edge.
Last reviewed 2026-09-24. 233 words.