Wooden pallets are made by cutting sawn lumber into boards, stringers or blocks, assembling them with nails in a fixed pattern, trimming and marking the finished unit, and, for export, heat treating it to meet ISPM 15. Production ranges from hand-nailed workshops to automatic lines that finish several hundred pallets an hour.
Overview of the process
The order of operations is similar in every plant, whatever the pallet type:
- Receive and inspect lumber
- Dry or condition the wood if necessary
- Cut components to length, width and thickness
- Prepare blocks or stringers (notching, chamfering)
- Assemble the pallet with nails
- Trim, chamfer and mark
- Heat treat and certify, if required
- Inspect, stack and dispatch
Plants differ in whether they build stringer or block pallets, work with new or recycled wood, and how automated the line is. The layout that connects these steps is covered in pallet factory layout.
From lumber to assembled pallet
1. Lumber intake and inspection
Pallets are built from low-grade sawn boards, usually softwood such as spruce, pine or fir, or mixed hardwood in some regions. Incoming lumber is checked against the order for:
- Dimensions and tolerances, including thickness variation
- Moisture content, measured with a pin or capacitance meter; see wood moisture content
- Defects such as large knots, splits, wane, rot and insect holes, assessed under lumber grading rules
- Bark. ISPM 15 requires wood packaging material to be debarked, with only small tolerated bark remnants; see debarked wood requirement
Rejecting poor lumber at the gate is cheaper than rejecting finished pallets. Wood is then stacked with stickers (spacers) to avoid mold and stain while waiting; see mould and blue stain.
2. Cutting components
Raw boards seldom arrive in final dimensions. A typical cutting sequence uses these machines:
- Cross-cut or cut-off saws to cut boards to pallet length, see cut-off and trim saws
- Multi-rip saws or band resaws to cut planks into narrower boards or thinner boards, see multi-rip saws
- Notching machines to cut notches into stringers for four-way fork entry, see notching and chamfering machines
Yield matters because lumber is the largest cost in a pallet. Cutting plans that minimize offcuts and use short pieces for blocks improve the result; see how to calculate pallet cost.
3. Block and stringer preparation
Blocks. Block pallets use nine blocks, three along each stringer board. Blocks are cut from solid wood offcuts or from pressed wood-chip material; see pallet blocks. EPAL pallets use standardized block dimensions and must meet quality rules for the block material.
Stringers. Stringer pallets use two or more long beams. After sawing to length, stringers may be notched for forklift or pallet jack entry and chamfered at the ends.
Boards. Deck boards are cut to length and, where specified, chamfered on the lower edges of the bottom lead boards so pallet jack wheels can roll onto the pallet.
4. Assembly and nailing
Assembly is the core of the process. The operator or machine places blocks or stringers in a jig, lays the top or bottom boards over them, and drives nails through the boards into the supports.
- Manual nailing uses a pneumatic nail gun and a simple jig. It suits small series and special sizes. See pneumatic nail guns.
- Semi-automatic nailing uses a nailing table or fixture where boards are positioned by hand and fastened by a machine.
- Fully automatic lines feed boards, blocks and stringers by conveyor and hopper, fasten them with multiple nailing heads and turn the pallet for the second deck. See pallet nailing machines and block pallet production lines.
The nail pattern is critical. EPAL specifies 78 nails for the Euro pallet, in an even, repeating arrangement that gives diagonal stiffness. Ring-shank or helical nails resist withdrawal better than smooth nails; see pallet nails and fasteners.
Assembly steps for a block pallet are usually: nail the bottom deck boards to the blocks and stringer boards, turn the unit, then nail the top deck boards. A stringer pallet is nailed in a similar sequence, with the stringers set into a jig first.
Finishing, treatment and dispatch
5. Trimming, chamfering and marking
Finished assemblies pass through finishing stations:
- Trim saws square the ends if boards overhang.
- Chamfering removes sharp edges where the pallet will contact racking or hands.
- Branding or stamping applies identification, such as the manufacturer's mark, EPAL branding on corner blocks, or the ISPM 15 stamp. Marking methods are compared in pallet branding and marking.
Marks must be legible and permanent. For solid-wood pallets in international trade, the ISPM 15 mark is applied only after treatment is complete, or under the control of the authorized company.
6. Heat treatment and drying
Pallets for export must be treated, most commonly by heat treatment: wood is heated until the core reaches at least 56 °C (133 °F) for a minimum of 30 continuous minutes. Treatment happens in a kiln chamber after assembly or on loose lumber before assembly, then the pallet is marked.
Kiln drying to a moisture target is a different process with a different purpose, though a kiln can do both; the distinction is explained in kiln-dried vs heat-treated. Plants hold ISPM 15 authorization from their national plant protection organization, and treatment records are kept.
7. Quality control
Quality checks run at several points:
| Stage | Typical checks |
|---|---|
| Incoming lumber | Dimensions, grade, moisture, visible defects |
| After cutting | Length, width and thickness tolerance, blocks sound |
| After nailing | Nail count and position, nail heads flush, no split boards or protruding points |
| After treatment | Core temperature log, correct stamp |
| Final | Dimensions, diagonal and flatness check, appearance, weight |
Sample pallets may be tested for load capacity. The key measuring and test standards are summarized in pallet testing standards and process controls in pallet quality control.
8. Stacking and dispatch
Completed pallets are stacked automatically or by hand in stacks of a defined height, which depends on pallet type and storage rules, and strapped or stored under cover. Wood that has been treated should be protected from rain to avoid regrowth of mold. Pallets are loaded onto trucks or into containers, often counted by stack to reduce errors.
Frequently asked questions
How long does it take to make one pallet?
It depends on automation. A single worker with a nail gun may take several minutes per pallet, while automatic lines complete several hundred per hour. Exact rates depend on the machine and pallet type.
What wood is used for pallets?
Mostly low-grade softwood such as spruce, pine or fir, and mixed hardwoods in some regions. Species choice depends on local supply, strength needs and cost.
Why are pallets heat treated?
Heat treatment kills pests living in raw wood and is required by ISPM 15 for solid-wood packaging crossing borders. The core temperature must reach 56 °C for at least 30 minutes.
Do all pallets use nails?
Most wooden pallets do. Some use screws, staples or adhesive, and plastic and metal pallets use other joining methods.
Sources
- EPAL Euro Pallet Quality Characteristics — European Pallet Association
- EUR-pallet — Wikipedia
- Regulation of wood packaging material in international trade (ISPM 15) — International Plant Protection Convention
- Pallet Fastener Testing — Virginia Tech Center for Packaging and Unit Load Design
- How Much Load Can My Pallet Carry? — Virginia Tech