Pallet Industry Glossary
A comprehensive reference of pallet industry terminology. From basic components like stringers and deck boards to compliance standards like ISPM-15, this glossary covers every term you will encounter when buying, selling, or recycling pallets.
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Block Pallet
A pallet constructed using blocks of solid wood (typically 9 blocks) between the top and bottom deck boards instead of stringers. Block pallets allow four-way entry for forklifts and pallet jacks from all four sides, making them more versatile than stringer pallets in tight warehouse environments. They are the standard design in Europe and are increasingly popular in North America.
Board Feet
A unit of measurement for lumber volume equal to a board that is 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches). Board feet is used to calculate the amount of raw lumber required to build a pallet and is a key factor in pricing. A standard 48x40 GMA pallet uses approximately 10 to 12 board feet of lumber.
Bottom Deck
The lower set of boards on a pallet, running parallel to the top deck boards. Bottom deck boards provide structural stability, distribute weight evenly when the pallet sits on a surface, and create the lower fork entry opening. A standard GMA pallet has five bottom deck boards. Pallets with more bottom deck boards offer greater racking load capacity because the weight is distributed across more contact points on the racking beams.
Chamfer
A beveled or angled cut made on the bottom edges of a pallet's lead boards (the outermost deck boards). Chamfering makes it easier for forklift tines and pallet jack forks to slide under the pallet smoothly without catching or damaging the wood. It is a standard feature on most quality pallets.
CHEP
An abbreviation for Commonwealth Handling Equipment Pool, a global pallet and container pooling company headquartered in Australia. CHEP operates a pallet rental program using distinctive blue wooden pallets. Businesses rent CHEP pallets rather than purchasing them, and the pallets are tracked, collected, repaired, and reissued by CHEP. CHEP pallets remain the property of CHEP and should not be bought or sold on the open market.
Combo Grade
A mixed load of pallets containing a variety of grades (A, B, C, and recycled) sold together at a blended price. Combo pallets offer the lowest per-unit cost and are ideal for buyers who need large volumes and can accept mixed quality. Every pallet in a combo load is structurally functional.
Closed Deck Pallet
A pallet with no gaps between the top deck boards, creating a solid, continuous surface. Closed deck pallets are used when small or irregularly shaped items need full support and cannot span gaps between boards. They are common in pharmaceutical, chemical, and food industries where product stability and contamination prevention are priorities. Closed deck pallets are heavier and more expensive than open deck designs.
Companion Stringer
An additional stringer board attached alongside an original stringer to reinforce a damaged or weakened pallet. Companion stringers are a common repair technique that restores load-bearing capacity without completely disassembling the pallet. This repair is often seen on Grade B and Grade C pallets and is considered a standard and acceptable repair method in the pallet recycling industry.
Cull Pallet
A pallet that has been inspected and deemed too damaged to be repaired, resold, or reused as a functional pallet. Cull pallets are dismantled for their usable lumber, which is then used to build recycled pallets. Boards, stringers, and blocks that cannot be salvaged are ground into mulch, animal bedding, or biomass fuel. At Universal Pallet Supply, no cull pallet material goes to landfill.
Deck Board
The horizontal boards that form the top and bottom surfaces of a pallet. Top deck boards support the load directly, while bottom deck boards provide stability and allow the pallet to sit flat on the floor or rack. Deck boards are typically 3/4 inch thick and vary in width from 3.5 to 5.5 inches depending on the pallet design.
Dynamic Load
The maximum weight a pallet can safely support while being moved by a forklift, pallet jack, or other handling equipment. Dynamic loads are lower than static loads because the pallet is subject to additional stresses from movement, vibration, and uneven lifting. A standard 48x40 GMA pallet supports approximately 2,500 pounds in dynamic load.
Dielectric Heating (DH)
A phytosanitary treatment method that uses microwave or radio-frequency energy to heat wood packaging materials to the ISPM-15 required temperature of 56 degrees Celsius for 30 minutes. Dielectric heating is faster than conventional kiln-based heat treatment because it heats the wood from the inside out. It is recognized by the IPPC as an approved alternative treatment method and is designated by the code DH on the ISPM-15 stamp.
Dunnage
Loose materials or structural supports used to protect cargo during shipping. Dunnage can include wood boards, foam, air bags, cardboard, or plastic bracing placed around, between, or under products to prevent shifting, vibration damage, and crushing. In the pallet industry, the term often refers to scrap lumber or wood pieces used to stabilize loads on pallets or inside containers.
EPAL
An abbreviation for European Pallet Association, the organization responsible for managing the EPAL/EUR pallet pool in Europe. EPAL pallets measure 800mm by 1200mm (approximately 31.5 by 47.3 inches) and are built to strict specifications. They are stamped with the EPAL logo and are the standard pallet for most European logistics operations.
Entry Point
The opening on a pallet that allows a forklift or pallet jack to insert its forks for lifting and moving. Standard stringer pallets have two entry points at the open ends. Notched stringer pallets and block pallets can have four entry points, one on each side. The number and placement of entry points determines how the pallet can be accessed in a warehouse, on a truck, or in a racking system.
Flush Pallet
A pallet where the deck boards are cut even (flush) with the outside edges of the stringers or blocks. This means no part of the pallet overhangs beyond its structural frame. Flush pallets fit precisely into racking systems and containers without any board ends protruding beyond the footprint.
Four-Way Entry
A pallet design that allows a forklift or pallet jack to access the pallet from all four sides. Block pallets are naturally four-way entry. Stringer pallets can achieve four-way entry by cutting notches into the stringers on the two sides where the stringers would otherwise block access. Four-way entry pallets are preferred in environments where aisle space is tight.
Fumigation
A pest treatment method that involves exposing wood to chemical gases, typically methyl bromide (MB), to kill insects and pathogens. Fumigation is an alternative to heat treatment for ISPM-15 compliance, though it is being phased out globally due to environmental concerns. Methyl bromide depletes the ozone layer, and many countries no longer accept fumigated wood. Heat treatment is the preferred and more sustainable alternative.
Fastener
Any nail, screw, staple, or bolt used to join the components of a pallet together. The most common pallet fastener is the helically threaded (spiral) nail, which provides superior holding power compared to smooth-shank nails. Standard GMA pallets use approximately 60 to 80 nails. Protruding or loose fasteners are a safety hazard and a common reason for pallet rejection during quality inspection.
Fork Opening
The horizontal gap between the top and bottom deck boards of a pallet where forklift forks or pallet jack tines are inserted. Fork openings are typically 3 to 4 inches high and must be clear of obstructions for safe handling. Insufficient fork opening height can cause forklifts to damage the pallet or drop the load.
GMA Pallet
The standard North American pallet measuring 48 inches by 40 inches, named after the Grocery Manufacturers Association (now the Consumer Brands Association). The GMA pallet is the most widely used pallet size in the United States, accounting for approximately 30% of all pallets produced. It is designed to fit standard truck trailers, warehouse racking, and retail receiving systems.
Grade A (Premium)
The highest quality grade for used pallets. Grade A pallets have been used only once or twice, appear nearly new, have no repaired or replaced boards, and show minimal cosmetic wear. They are suitable for export, retail displays, automated warehouse systems, and applications where appearance matters.
Grade B (Standard)
The most popular grade for used pallets, representing the best balance between quality and value. Grade B pallets may show moderate wear, minor discoloration, and may have one or two professionally repaired boards. They are structurally sound and suitable for general warehousing, domestic shipping, and manufacturing.
Grade C (Economy)
The most affordable grade for used pallets. Grade C pallets show significant wear with dark wood, multiple repaired boards, and visible cosmetic imperfections. Despite their appearance, they remain structurally functional and are ideal for internal warehouse use, short-distance transport, and applications where aesthetics are irrelevant.
Hardwood
Wood from deciduous (leaf-shedding) trees such as oak, maple, birch, and beech. Hardwood pallets are generally stronger and more durable than softwood pallets but are also heavier and more expensive. They are preferred for heavy-load applications, export shipments, and situations where the pallet will be reused many times.
Heat Treatment (HT)
A phytosanitary process required by ISPM-15 for international shipping. The core temperature of the wood must reach at least 56 degrees Celsius (132.8 degrees Fahrenheit) for a minimum of 30 continuous minutes. This kills pests and pathogens without chemicals. Heat-treated pallets are stamped with the HT mark and the IPPC logo.
ISPM-15
International Standards for Phytosanitary Measures No. 15, a set of guidelines developed by the International Plant Protection Convention (IPPC) to prevent the spread of pests and diseases through wood packaging materials in international trade. ISPM-15 requires that all solid wood packaging (including pallets, crates, and dunnage) be heat-treated or fumigated and marked with the IPPC stamp before crossing international borders.
IPPC Stamp
The official mark applied to wood packaging materials that have been treated in accordance with ISPM-15 standards. The stamp includes the IPPC wheat stalk symbol, a two-letter country code, a unique producer or treatment facility number assigned by the national plant protection organization, and a treatment code (HT for heat treatment, MB for methyl bromide, or DH for dielectric heating). The stamp must be legible, permanent, and visible on at least two opposite sides of the pallet.
Kiln-Dried (KD)
Wood that has been dried in a controlled kiln environment to reduce its moisture content, typically to 19 percent or below. Kiln-drying reduces pallet weight, minimizes warping and shrinkage, and inhibits mold and fungal growth. While kiln-drying and heat treatment both involve applying heat, they serve different purposes. Kiln-drying is a moisture reduction process, while heat treatment (HT) is a phytosanitary pest elimination process required by ISPM-15. A pallet can be kiln-dried without being heat treated, and vice versa.
Lead Board
The outermost deck boards on a pallet, located at the front and back edges. Lead boards take the most abuse during forklift handling and are often the first boards to break or need replacement. On quality pallets, lead boards are typically wider and thicker than interior deck boards to withstand repeated forklift contact.
Load Bearing Capacity
The maximum weight a pallet is designed to safely support under specific conditions. Pallet load bearing capacity is expressed in three ratings: static load (pallet on a flat surface), dynamic load (pallet being moved by handling equipment), and racking load (pallet spanning racking beams). These ratings depend on the pallet design, wood species, moisture content, board dimensions, fastener pattern, and condition. Always verify the load bearing capacity for your specific use case before loading.
Moisture Content
The amount of water present in wood, expressed as a percentage of the dry weight of the wood. Fresh-cut (green) lumber can have moisture content above 60 percent. Properly dried pallet lumber should have moisture content between 12 and 22 percent. High moisture content increases pallet weight, promotes mold growth, reduces structural strength, and can cause products to absorb moisture. Kiln-drying reduces moisture content to 19 percent or below.
Notch
A cutout made in the bottom of a stringer to allow partial four-way entry for forklift forks. Notches are typically 1.5 inches deep and 9 inches wide, cut at regular intervals along the stringer. Notched stringers allow forklifts to access the pallet from the notched sides while pallet jacks can only enter from the two open ends.
Nestable Pallet
A pallet designed so that empty pallets can be stacked inside each other (nested) to save space during storage and return shipping. Nestable pallets typically have a nine-post or pedestal design rather than continuous stringers. They are most commonly made from plastic but can also be constructed from wood. Nestable pallets are popular in one-way shipping and return logistics where minimizing the space occupied by empty pallets is important.
NWPCA
An abbreviation for the National Wooden Pallet and Container Association, the largest organization representing the wood packaging industry in North America. Founded in 1947, the NWPCA sets industry standards, provides member certification programs, and advocates for the wooden pallet industry. NWPCA operates the Pallet Design System (PDS) software used to engineer pallet designs for specific load and handling requirements.
Overhang
The distance that deck boards extend beyond the outer edge of a stringer or block on a pallet. Overhang can be intentional (as in wing pallets, where it adds surface area) or unintentional (due to misalignment during manufacturing or repair). Excessive overhang can interfere with racking systems, cause boards to break when forklifts strike the protruding edges, and create dimensional issues for automated handling equipment.
Pallet Collar
A hinged wooden frame that sits on top of a pallet to create a box-like enclosure for goods. Pallet collars can be stacked multiple layers high to increase the height of the enclosure. They fold flat when not in use, making them space-efficient for return shipping. Pallet collars are a reusable alternative to cardboard boxes for pallet-sized shipments.
Pallet Jack
A wheeled hand tool used to lift and move pallets short distances within a warehouse or loading dock. Pallet jacks insert their forks into the openings between a pallet's deck boards and stringers or blocks, then use a hydraulic pump to lift the pallet slightly off the ground for transport. They are the most common pallet handling tool in small to mid-size warehouses.
Pallet Pooling
A logistics model where pallets are rented from a pooling company rather than purchased. The pooling company (such as CHEP or PECO) owns, tracks, collects, repairs, and redistributes the pallets. Businesses pay a per-trip or per-cycle fee. Pooling reduces the need to purchase and manage pallets but can be expensive for long supply chains or when pallet returns are difficult to track.
Pallet Exchange
A logistics practice where the delivery driver swaps loaded pallets for empty ones at the point of delivery. The empty pallets are returned to the shipper for reuse. Pallet exchange programs reduce costs by keeping pallets in circulation rather than treating them as disposable. In Europe, the EPAL pallet exchange system operates across 30 countries with over 500 million pallets in the pool. In North America, pallet exchanges are typically arranged between individual trading partners.
Pallet Repair
The process of restoring a damaged pallet to a usable condition by replacing broken boards, re-nailing loose components, straightening bent nails, and removing protruding fasteners. Pallet repair extends the useful life of a pallet by 2 to 5 additional use cycles and costs 30 to 50 percent less than purchasing a new pallet. Repaired pallets are regraded based on their post-repair condition and the number of replacement boards used.
Pinwheel Stacking
A method of arranging pallets on a truck trailer where alternating pallets are rotated 90 degrees to maximize the number of pallets that fit. In a standard 53-foot trailer, pinwheel loading (also called double pinwheel) fits 26 standard 48x40 GMA pallets, compared to 20 pallets when loaded straight. Pinwheel stacking is the standard loading pattern for most North American freight.
Racking Load
The maximum weight a pallet can safely support while spanning the beams of a pallet racking system. In this configuration, the pallet is supported only at its two ends with the center unsupported. Racking loads are typically lower than static loads because of the bending stress on the deck boards and stringers. A standard 48x40 GMA pallet supports approximately 2,200 to 2,500 pounds in racking load.
Slip Sheet
A thin sheet of corrugated fiberboard, solid fiberboard, or plastic used as a pallet alternative. Slip sheets are placed under a unit load, and a push-pull forklift attachment grips the protruding edge of the sheet to lift and move the load. Slip sheets save space and weight compared to pallets and are popular for export shipping where pallet return is not practical.
Softwood
Wood from coniferous (cone-bearing, evergreen) trees such as pine, spruce, and fir. Softwood is the most common material for pallets in North America due to its lower cost and abundant availability. Softwood pallets are lighter than hardwood pallets, which reduces shipping costs, but they may be less durable under heavy loads or repeated use.
Static Load
The maximum weight a pallet can safely support while sitting stationary on a flat, solid surface such as a warehouse floor. Static loads are the highest load capacity rating because the weight is evenly distributed across the entire pallet. A standard 48x40 GMA pallet supports approximately 2,800 pounds or more in static load.
Stringer
A long, rectangular piece of dimensional lumber (typically a 2x4 or 2x3) that runs the length of a stringer pallet, connecting the top and bottom deck boards. Most stringer pallets have three stringers: one on each side and one in the center. Stringers provide the structural backbone of the pallet and bear the load when the pallet is lifted by a forklift or resting on racking beams.
Stringer Pallet
A pallet constructed using stringers (long rectangular boards) as the primary structural elements between the top and bottom deck boards. Stringer pallets are the most common pallet type in North America. In their basic form, they allow two-way forklift entry (from the two open ends), but notches can be cut into the stringers to allow four-way entry.
Skid
A pallet-like platform that has a top deck but no bottom deck boards. Skids sit directly on their stringers or runners, which act as both structural support and sliding surfaces. The term skid predates the modern pallet and was originally designed to be dragged (skidded) rather than lifted. Today, the terms skid and pallet are sometimes used interchangeably, but technically a skid has no bottom deck.
Stretch Wrap
A thin, stretchable plastic film used to secure products to a pallet for stability during shipping and storage. Stretch wrap is applied by hand or by machine and clings to itself without adhesive. Proper stretch wrapping prevents load shifting, protects products from dust and moisture, and provides tamper evidence. Most palletized loads are wrapped with 3 to 5 layers of stretch film, with extra wraps at the top and bottom for security.
Two-Way Entry
A pallet design that only allows a forklift or pallet jack to access the pallet from two of its four sides, specifically the two open ends where the stringers do not block access. Two-way entry is the basic configuration of an un-notched stringer pallet. These pallets are less versatile than four-way entry pallets but are simpler and less expensive to manufacture.
Top Cap
A flat sheet of corrugated cardboard, plastic, or plywood placed on top of a palletized load before stretch wrapping. Top caps protect the upper layer of products from compression damage if another pallet is stacked on top, prevent the stretch wrap from cutting into soft products, and provide a smooth surface for stacking. They are standard practice in food and beverage, consumer goods, and pharmaceutical logistics.
Unit Load
A quantity of goods assembled on a pallet and secured as a single unit for handling, storage, and transportation. The unit load concept is the foundation of modern logistics. By consolidating individual items into a single palletized unit, warehouses can move, store, and ship products more efficiently using forklifts, conveyors, and racking systems. Unit load design considers pallet size, product dimensions, stacking patterns, weight distribution, and securing methods.
Wing Pallet
A pallet where the deck boards extend beyond the outside edges of the stringers or blocks, creating an overhang or wing on one or both sides. Wings increase the usable surface area of the pallet without changing its structural footprint. Winged pallets are often used when the load slightly exceeds the stringer width or when additional board surface is needed for stretch-wrapping.
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