Pallet Terminology Glossary
A comprehensive reference of over 60 pallet industry terms, definitions, and concepts. From block pallets to ISPM-15, everything you need to understand the language of the pallet industry.
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A-D
23 terms
Automated Guided Vehicle (AGV)
A self-driving material handling vehicle used in warehouses and distribution centers to transport palletized loads without human operators. AGVs require pallets with consistent dimensions and flat bottom decks to function reliably. Block pallets are generally preferred for AGV operations because they offer four-way entry and uniform dimensions.
ASTM International
Formerly known as the American Society for Testing and Materials, ASTM International develops and publishes voluntary consensus technical standards for a wide range of materials, products, and services, including pallets. Key pallet standards include ASTM D1185 (Standard Test Methods for Pallets and Related Structures Employed in Materials Handling and Shipping) and ASTM D6253 (Standard Guide for Evaluating the Performance of Pallet Recyclability).
Banding
The process of securing a load to a pallet using steel or polyester straps (bands) that wrap around the product and the pallet structure. Banding is commonly used in conjunction with stretch wrapping to prevent load shift during transit. Steel banding provides the highest tensile strength, while polyester banding is lighter and does not rust.
Bark
The outer covering of a tree trunk that may remain on rough-sawn pallet lumber. Excessive bark on pallet boards is considered a defect because it can harbor insects, trap moisture, and flake off during handling. ISPM-15 regulations require that bark strips on treated wood be less than 3 cm wide. Pallets with significant bark presence are typically downgraded to Grade C or Economy.
Block Pallet
A pallet constructed using blocks (typically nine) of solid wood, plywood, or composite material positioned between the top and bottom deck boards. Block pallets offer true four-way fork entry, making them accessible from all four sides by both forklifts and pallet jacks. They are generally stronger and more durable than stringer pallets, which is why they are the standard in European logistics (EUR pallets) and are increasingly popular in North America.
Board Foot
A unit of lumber volume measurement equal to a 1-inch thick board that is 12 inches wide and 12 inches long (144 cubic inches). Board feet are used throughout the lumber and pallet industry to calculate raw material costs. A standard 48x40 GMA pallet requires approximately 10 to 12 board feet of lumber to manufacture, depending on board thickness and configuration.
Bottom Deck
The lower platform of a pallet, consisting of boards or panels that make contact with the floor, racking, or conveyor. The bottom deck provides structural support and distributes the load across the storage surface. Some pallets (single-face pallets) have no bottom deck at all, while double-face pallets have bottom decks that may be either flush or recessed.
Captive Pallet
A pallet that is used exclusively within a single facility or closed-loop supply chain and is not intended to leave the premises. Captive pallets are typically higher quality and more durable because they are expected to complete hundreds or even thousands of internal trips. Companies invest more per unit in captive pallets because the long service life justifies the upfront cost.
Chamfer
A beveled or angled cut on the leading edge of a pallet stringer or bottom board, designed to facilitate easier fork entry. Chamfers are typically cut at a 45-degree angle and extend 1.5 to 2 inches along the board edge. Proper chamfering reduces damage to both pallets and forklifts during handling and is a critical feature for pallets used in automated systems.
Check
A lengthwise separation of wood fibers that does not extend through the entire thickness of a board, caused by stresses during drying or seasoning. Checks are a common and generally minor defect in pallet lumber. Small checks (under 6 inches) do not significantly affect structural integrity, but deep or extensive checking can weaken boards and make them susceptible to splitting under load.
CHEP
Commonwealth Handling Equipment Pool, the world's largest pallet pooling company. CHEP operates a system of distinctive blue pallets that are rented to manufacturers, retailers, and distributors rather than sold. The CHEP pallet is a 48x40-inch block pallet that meets strict quality standards. The pooling model reduces waste by keeping pallets in continuous circulation and maintaining them through a network of service centers.
Closed-Loop System
A pallet management system where pallets are shipped from a point of origin to a destination and then returned to the original sender for reuse. Closed-loop systems maximize pallet lifespan, reduce per-trip costs, and minimize environmental impact. They require coordination between supply chain partners and are most effective when shipping routes are predictable and consistent.
Combo Pallet
A pallet with a combination of new and used or recycled components. Combo pallets may use new stringers with recycled deck boards, or vice versa, to balance cost savings with structural integrity. This approach is more economical than all-new construction and more reliable than fully recycled pallets. Fresno Pallets builds combo pallets to meet specific customer requirements.
Corrugated Pallet
A pallet made entirely from corrugated fiberboard (heavy-duty cardboard). Corrugated pallets are extremely lightweight (typically 5 to 15 pounds), fully recyclable, exempt from ISPM-15 treatment requirements, and ideal for air freight or one-way export shipments. Their load capacity is lower than wood (typically 500 to 2,500 pounds), and they are not suitable for outdoor storage or wet environments.
Cross-Docking
A logistics strategy where incoming shipments are unloaded from inbound trailers and immediately loaded onto outbound trailers with minimal or no warehousing. Cross-docking operations demand pallets with consistent dimensions and structural reliability because goods move rapidly with little time for inspection. Grade A or B pallets are strongly recommended for cross-docking environments.
Cruciform Pattern
A pallet stacking pattern where each layer of boxes is arranged in a cross (plus-sign) shape, creating an interlocking structure that resists shifting during transit. The cruciform pattern sacrifices some deck surface utilization for improved stability and is commonly used for tall, narrow products on standard 48x40 pallets.
Deck Board
Any board that forms the top or bottom surface of a pallet. Deck boards are the primary contact surface for the cargo placed on the pallet. They are typically 3/4 inch (19mm) or 5/8 inch (16mm) thick and come in widths ranging from 3.5 to 5.5 inches. The number and spacing of deck boards determine the pallet's load distribution capability, weight capacity, and suitability for different product sizes.
Deck Board Spacing
The gap between adjacent deck boards on a pallet. Standard spacing varies from 0 inches (closed deck) to approximately 2.5 inches. Tight spacing supports smaller or irregularly shaped loads and prevents products from falling through or becoming wedged. Wide spacing reduces material cost and pallet weight but limits the minimum size of boxes the pallet can support.
Deck Mat
A section of the pallet's top or bottom surface assembled as a unit, typically consisting of multiple deck boards fastened to lead boards. Deck mats are prefabricated and then attached to the stringers or blocks during final pallet assembly, improving manufacturing efficiency and consistency.
Depalletizer
An automated machine that removes layers of products from a pallet, typically at the end of a shipping process before products enter retail stocking or secondary distribution. Depalletizers require pallets with consistent dimensions and flat, stable surfaces to operate without jamming or misfeeds.
Double-Face Pallet
A pallet with both top and bottom deck boards, providing two load-bearing surfaces. Double-face pallets can be either reversible (both decks are identical and can be used as the top) or non-reversible (the top and bottom decks differ in board count or spacing). Double-face pallets provide superior stability in racking systems and distribute weight more evenly on warehouse floors.
Dunnage
Loose materials used to protect cargo during transit, including lumber, airbags, foam, or cardboard placed on, around, or between palletized loads. In the pallet industry, dunnage also refers to scrap lumber and pallet components that are repurposed as load-separation or gap-filling material in trucks and containers.
Dynamic Load Capacity
The maximum weight a pallet can safely support while being moved by a forklift or pallet jack. Dynamic load capacity is always lower than static load capacity because the pallet must withstand the additional stresses of acceleration, deceleration, turning, and uneven surfaces. A standard 48x40 GMA pallet has a dynamic load capacity of approximately 2,800 pounds when evenly distributed.
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17 terms
Edge Board (Corner Board)
An L-shaped protective device made of compressed paperboard, plastic, or metal placed on the vertical edges of a palletized load to prevent strap damage and provide stacking strength. Edge boards distribute the compressive force of stacked loads and prevent banding or stretch wrap from cutting into product packaging. They are essential for protecting fragile goods during transit.
EUR Pallet (Euro Pallet)
A standardized pallet measuring 1200 x 800 mm (approximately 47.2 x 31.5 inches), licensed and regulated by the European Pallet Association (EPAL). EUR pallets are block pallets with four-way entry, a specific nail pattern, and must carry the EPAL/EUR marking. They are the dominant pallet type in European supply chains, with over 500 million in active circulation.
Exchange Pallet
A pallet that is swapped on a one-for-one basis between supply chain partners. When a loaded pallet is delivered, the receiver provides an empty pallet of equivalent quality in return. This exchange system keeps pallets in circulation and avoids the cost of one-way pallets. Exchange programs require agreement on pallet specifications, condition standards, and dispute resolution processes.
Export Pallet
A pallet specifically designed and treated for international shipment. Export pallets must comply with ISPM-15 regulations, which require heat treatment (HT) or methyl bromide fumigation (MB) to prevent the spread of invasive insects and plant diseases. Export pallets carry the internationally recognized IPPC stamp indicating compliance. Non-compliant pallets may be rejected at the port of entry, quarantined, or destroyed.
Fastener
Any device used to join pallet components together, including nails, screws, staples, and bolts. The type, size, and placement of fasteners directly affect pallet strength, durability, and repairability. Helically threaded (spiral) and annularly threaded (ring-shank) nails provide superior holding power compared to smooth-shank nails and are recommended for pallets that will be reused multiple times.
Flush Pallet
A pallet where the deck boards are cut even with the outer edges of the stringers or blocks, creating a perfectly rectangular footprint with no overhang. Flush pallets maximize stacking stability, reduce damage from protruding boards catching on other pallets or rack structures, and are preferred for automated warehouse systems and tight storage configurations.
Four-Way Entry
A pallet design that allows forklifts and pallet jacks to enter from all four sides. Block pallets inherently provide four-way entry due to their block construction. Stringer pallets can be modified to allow four-way entry by cutting notches into the center stringer, though full four-way entry on stringer pallets typically means forklift-only access on the stringer sides (pallet jacks cannot enter).
Fumigation
The process of treating wood pallets with chemical gases (most commonly methyl bromide) to eliminate insects, larvae, and pathogens. Fumigation was historically the primary treatment method for export pallets but is being phased out in many countries due to environmental concerns. Methyl bromide is an ozone-depleting substance, and many nations now require heat treatment as the preferred alternative under ISPM-15.
GMA Pallet
The standard North American pallet size of 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, representing approximately 30% of all new pallets produced. It is designed to optimize space in 53-foot dry van trailers, where 20 to 21 GMA pallets fit per load depending on loading pattern.
Grade A Pallet
The highest quality classification for a used pallet. Grade A pallets are in like-new condition with no significant damage, repairs, staining, or contamination. All boards are intact and original, nails are flush, and the pallet retains its full structural capacity. Grade A pallets are suitable for food and pharmaceutical applications, retail distribution to major chains, export shipments, and automated warehouse systems.
Grade B Pallet
A used pallet in good overall condition with minor cosmetic imperfections. Grade B pallets may have one or two professionally replaced boards, slight staining or discoloration, and minor surface wear. Structural integrity is fully maintained. Grade B is the most popular grade for general warehousing, manufacturing, and B2B shipping because it offers excellent functionality at a moderate price point.
Grade C Pallet
A used pallet with visible wear and multiple repairs that remains structurally sound for its intended purpose. Grade C pallets show significant cosmetic issues including heavy staining, weathering, mixed board colors from repairs, and general rough appearance. They are suitable for one-way shipments, internal warehouse transfers, construction site use, and applications where appearance is not a concern.
Grocery Pallet
A colloquial term for the standard 48x40-inch GMA pallet used extensively in the grocery and consumer packaged goods (CPG) industries. Grocery pallets must be clean, structurally sound, free of odors and contamination, and compatible with automated distribution center equipment. Most major grocery retailers specify Grade A or premium Grade B pallets for inbound shipments.
Hardwood
Wood from deciduous (broad-leaved) trees such as oak, maple, birch, beech, and poplar. Hardwood pallets are denser, heavier, and generally stronger than softwood pallets, making them the preferred choice for heavy-load applications, export pallets, and long-lifespan captive pallets. Common hardwood species in Fresno area pallet manufacturing include oak and mixed hardwoods sourced from the Pacific coast and inland regions.
HDPE (High-Density Polyethylene)
A thermoplastic polymer used to manufacture plastic pallets through injection molding or rotational molding processes. HDPE pallets are lightweight, resistant to moisture, chemicals, and insects, and can be easily cleaned and sanitized. They are exempt from ISPM-15 treatment requirements and are popular in pharmaceutical, food processing, and cleanroom applications where hygiene is critical.
Heat Treatment (HT)
A phytosanitary treatment process in which wood is heated until its core temperature reaches a minimum of 56 degrees Celsius (132.8 degrees Fahrenheit) for at least 30 consecutive minutes. Heat treatment kills insects, larvae, nematodes, and other organisms that could spread to new ecosystems. It is the globally preferred ISPM-15 treatment method because it uses no chemicals and does not leave residues on the wood.
Hybrid Pallet
A pallet constructed from a combination of materials, such as a wood frame with a plastic or metal deck, or a plastic base with wood stringers. Hybrid pallets aim to combine the best properties of multiple materials — for example, the low cost of wood with the hygiene benefits of plastic. They are used in specialized applications where a single material cannot meet all requirements.
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8 terms
Injection Molded Pallet
A plastic pallet produced by injecting molten polymer (typically HDPE or PP) into a steel mold under high pressure. Injection molding creates pallets with precise dimensions, smooth surfaces, and consistent quality. These pallets are more expensive than wood but offer superior hygiene, chemical resistance, and dimensional accuracy. They are widely used in food processing, pharmaceuticals, and automated warehousing.
IPPC (International Plant Protection Convention)
A United Nations treaty organization that governs the ISPM-15 standard for international wood packaging materials. The IPPC stamp on a pallet indicates that the wood has been properly treated and inspected according to international phytosanitary standards. The stamp includes the country code, producer number, treatment type (HT or MB), and the IPPC wheat-stalk logo.
ISPM-15
International Standards for Phytosanitary Measures No. 15, the global standard that regulates wood packaging materials in international trade. ISPM-15 requires that all solid wood packaging (including pallets, crates, and dunnage) be either heat treated or fumigated to prevent the spread of invasive pests. Compliance is indicated by the IPPC mark, which must be clearly visible on at least two opposite sides of the pallet. Over 180 countries enforce ISPM-15 regulations.
Kiln-Dried (KD)
Lumber that has been dried in a controlled kiln environment to reduce its moisture content, typically to 19% or below. Kiln drying is distinct from heat treatment for ISPM-15 purposes, though kiln drying can qualify as heat treatment if the wood core reaches the required temperature for the required duration. Kiln-dried lumber is dimensionally more stable, lighter, and less susceptible to mold growth than green (freshly cut) lumber.
Lead Board
The outermost deck board at the ends of a pallet, perpendicular to the stringers. Lead boards experience the most stress during forklift handling because they are the first point of contact during fork entry. They are often made from thicker or stronger lumber than interior deck boards and are the most frequently replaced component during pallet repair.
Licensed Treatment Provider
A facility authorized by a national plant protection organization to perform ISPM-15 heat treatment or fumigation and to apply the official IPPC mark to treated wood packaging. Licensed providers must maintain calibrated equipment, follow prescribed treatment protocols, keep detailed records, and submit to periodic audits. Using wood packaging treated by an unlicensed provider can result in shipment rejection at international borders.
Load-Bearing Surface
The total area of the pallet deck that makes contact with the product being shipped. A pallet with tightly spaced deck boards has a larger load-bearing surface than one with wide gaps between boards, which improves weight distribution and reduces the risk of product damage. Closed-deck pallets offer the maximum load-bearing surface and are preferred for small, irregularly shaped, or delicate items.
Liftruck (Forklift)
A powered industrial vehicle used to lift, lower, and transport palletized loads within warehouses, distribution centers, and shipping yards. Forklifts interact directly with pallets through fork openings or notches, and improper forklift operation is the leading cause of pallet damage. Operators should insert forks fully, center loads, approach straight on, and avoid dragging pallets across floors.
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15 terms
Mold (Mould)
Fungal growth that appears as discoloration (typically blue, black, green, or white) on the surface of wood pallets. Mold develops when wood moisture content exceeds 20% in the presence of warm temperatures and stagnant air. Surface mold on pallets is largely cosmetic and can be cleaned, but deep mold penetration weakens wood fibers and can render pallets unsuitable for food-contact applications. Prevention through proper drying, ventilation, and storage practices is far more effective than remediation.
Methyl Bromide (MB)
A fumigant gas historically used to treat wood pallets for international shipping under ISPM-15. Methyl bromide is highly effective at killing insects and pathogens but is classified as an ozone-depleting substance under the Montreal Protocol. Its use has been banned or severely restricted in most developed countries, and heat treatment has largely replaced it as the preferred phytosanitary treatment for wood packaging materials.
Nestable Pallet
A pallet designed with angled or tapered legs that allow empty pallets to stack (nest) inside each other, dramatically reducing the space required for storage and return shipping. Nestable pallets are typically made from plastic and can reduce empty pallet storage space by up to 75% compared to standard stackable pallets. They are popular for one-way shipments and in space-constrained warehouse environments.
Notch
A rectangular or U-shaped cutout in the bottom of a stringer pallet that allows forklift fork entry from the sides. Notches are typically 9 inches wide and 1.5 inches deep, creating partial four-way entry on stringer pallets. While notches allow forklift access from all four sides, pallet jacks can only enter from the two ends where full openings exist between the stringers.
NWPCA (National Wooden Pallet and Container Association)
The largest trade organization representing the wood packaging industry in the United States. NWPCA provides industry standards (including the Uniform Standard for Wood Pallets), training programs, advocacy, and the PDS (Pallet Design System) software used to engineer pallets for specific load requirements. NWPCA members include pallet manufacturers, recyclers, lumber suppliers, and equipment vendors.
Overhang
The distance that the deck boards extend beyond the outer edge of the stringers or blocks. Some overhang (typically 0.5 to 1 inch) is common and intentional in many pallet designs, but excessive overhang can cause deck boards to catch on racking, conveyors, or adjacent pallets, leading to damage. Flush pallets, which have no overhang, are required for many automated systems.
Pallet Collar
A hinged wooden or plastic frame that sits on top of a pallet to create a box-like enclosure for containing loose or irregularly shaped products. Multiple collars can be stacked to increase the height of the enclosure. Pallet collars fold flat when not in use, making them space-efficient for return shipping. They are widely used in European automotive and manufacturing supply chains.
Pallet Design System (PDS)
A proprietary software program developed by the NWPCA and Virginia Tech that allows pallet designers to calculate the structural performance of different pallet configurations. PDS considers factors including wood species, board dimensions, fastener types, load weight, load distribution, and handling conditions to predict deflection, durability, and failure modes. It is the industry standard for engineering custom pallet designs.
Pallet Jack (Pallet Truck)
A manual or powered wheeled vehicle used to lift and move pallets within a facility. Pallet jacks insert their forks into the openings between the bottom deck boards and the floor, then hydraulically lift the pallet a few inches for transport. Unlike forklifts, pallet jacks can only enter a pallet from sides with full-length openings, which is why four-way entry pallets are preferred in facilities that use both forklifts and pallet jacks.
Pallet Pooling
A system where a third-party company (such as CHEP, PECO, or iGPS) owns and manages a large fleet of standardized pallets that are rented to supply chain participants. The pooling company handles pallet recovery, inspection, repair, and redistribution. Pooling reduces the administrative burden of pallet management, ensures consistent quality, and supports sustainability by maximizing pallet reuse cycles.
Pallet Racking
A storage system of steel upright frames and horizontal beams designed to hold palletized loads above floor level, maximizing vertical warehouse space. Racking systems require pallets with specific dimensional tolerances, load capacities, and structural integrity. Improperly sized, damaged, or overloaded pallets in racking systems create serious safety hazards including collapse, product damage, and worker injury.
PECO Pallet
The second-largest pallet pooling company in North America, identifiable by their distinctive red pallets. PECO operates a fleet of 48x40-inch block pallets that are designed for the grocery and consumer packaged goods industries. PECO pallets feature a closed-bottom deck design that is compatible with automated handling systems and provides excellent performance in racking.
Pinwheel Pattern
A pallet loading pattern where boxes in each layer are arranged in alternating orientations, creating a pinwheel or windmill appearance when viewed from above. This interlocking pattern provides excellent stability without requiring additional securing devices. It is particularly effective for square or nearly-square cases and is one of the most commonly used stacking patterns in the grocery industry.
Plywood Pallet
A pallet constructed using engineered plywood panels instead of individual deck boards. Plywood pallets offer a completely flat, continuous load-bearing surface, making them ideal for bagged goods, small items, and products that could be damaged by gaps between deck boards. Plywood is also lighter than an equivalent area of solid lumber deck boards, which can reduce shipping costs for weight-sensitive shipments.
Presswood Pallet (Molded Wood Pallet)
A pallet manufactured by compressing wood fibers, chips, or sawdust with resin binders under high temperature and pressure. Presswood pallets are lightweight (typically 15 to 20 pounds for a 48x40), nestable, exempt from ISPM-15 treatment requirements (because the manufacturing process exceeds HT parameters), and made from recycled wood waste. Their load capacity is lower than solid wood, making them best suited for lightweight to medium loads and one-way export shipments.
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17 terms
Racking Load Capacity
The maximum weight a pallet can safely support when placed on a pallet racking system with only the outer edges supported by the rack beams. Racking load capacity is the most demanding load scenario for a pallet because the middle of the pallet is unsupported and must resist bending. A standard 48x40 GMA stringer pallet has a typical racking load capacity of 2,000 to 2,500 pounds, while a well-built block pallet may support 2,500 to 3,000 pounds in racking.
Recycled Pallet
A used pallet that has been collected, inspected, repaired as needed, and returned to service. Recycled pallets are the most environmentally friendly and cost-effective option for most shipping applications. Each time a pallet is recycled rather than discarded, it saves approximately 3.1 board feet of new lumber, diverts 30 to 60 pounds of wood from landfills, and reduces the carbon footprint of the supply chain. Fresno Pallets processes thousands of recycled pallets monthly.
Regrind Pallet
A plastic pallet manufactured from reground (recycled) plastic material rather than virgin resin. Regrind pallets are more affordable than virgin-resin pallets and support circular economy principles, though they may have slightly lower impact resistance and less consistent color. Many plastic pallet manufacturers offer regrind pallets as an eco-friendly alternative.
Reversible Pallet
A double-face pallet where both the top and bottom decks are identical in construction, allowing either side to be used as the load-bearing surface. Reversible pallets effectively double the wear surface, extending pallet life in applications where deck board damage is the primary failure mode. They are particularly popular in heavy industrial environments where top-deck damage from rough handling is common.
Single-Face Pallet
A pallet with deck boards on only one side (the top), leaving the stringers or blocks exposed on the bottom. Single-face pallets are the simplest and least expensive pallet type. They are suitable for lightweight loads, static storage, and applications where the pallet will not be placed in racking. Single-face pallets are not recommended for automated handling systems or for loads that will be stacked multiple levels high.
Skid
A pallet without a bottom deck, consisting of only a top deck surface attached to stringers or runners. Technically, a skid predates the modern pallet and was the original platform for moving goods with forklifts. The terms skid and pallet are often used interchangeably in casual conversation, but the distinction is important in logistics specifications because skids do not perform as well in racking systems.
Slip Sheet
A thin sheet of heavy-duty corrugated fiberboard, solid fiberboard, or plastic placed under a unit load as an alternative to a traditional pallet. Slip sheets are handled by forklifts equipped with special push-pull attachments. They are significantly cheaper and lighter than pallets and take up virtually no space, but require specialized equipment and trained operators. They are most common in export shipments where pallets would add significant weight and cost.
Softwood
Wood from coniferous (evergreen) trees such as pine, spruce, fir, and cedar. Softwood is the most commonly used material for pallet manufacturing in North America due to its abundance, low cost, light weight, and ease of nailing and cutting. Southern Yellow Pine (SYP) is the dominant softwood species for pallets in the southeastern United States, while SPF (Spruce-Pine-Fir) dominates in Canada and the northern states.
Southern Yellow Pine (SYP)
A group of pine species native to the southeastern United States that is the single most common wood used in American pallet manufacturing. SYP is valued for its fast growth rate, wide availability, excellent strength-to-weight ratio, and good nail-holding properties. It is moderately heavy, resists splitting better than many other softwoods, and accepts heat treatment well for export applications.
SPF (Spruce-Pine-Fir)
A group of softwood species commonly harvested together in Canada and the northern United States. SPF lumber is lightweight, light in color, and relatively soft, making it popular for lightweight pallets and applications where low weight is important. It is less dense and somewhat weaker than Southern Yellow Pine but is widely available and cost-effective. SPF pallets weigh 10 to 15 percent less than equivalent SYP pallets.
Split
A lengthwise separation of wood that extends through the full thickness of a board, typically caused by excessive force during nailing, impact damage, or stress from drying. Splits are a more serious defect than checks because they compromise the structural integrity of the affected board. A board with a split longer than half its width should be replaced during pallet repair.
Stacking Load Capacity (Static Load Capacity)
The maximum weight a pallet can support when it is stationary and sitting on a flat, level surface with the entire bottom deck in contact with the floor. Static load capacity is the highest of the three standard load ratings (static, dynamic, and racking) because the load is evenly distributed and the pallet is not subject to handling stresses. A standard 48x40 GMA pallet typically supports 5,000 to 7,500 pounds in a static load scenario.
Stringer
A continuous structural member that runs the full length of a pallet, connecting the top and bottom deck boards and providing the primary structural support. Most stringer pallets use three stringers — two outer stringers and one center stringer. Stringers are typically 1.5 inches thick and 3.5 inches tall for standard pallets, though heavy-duty pallets may use thicker or taller stringers for increased load capacity.
Stringer Pallet
The most common pallet type in North America, constructed with two or three parallel stringers running the length of the pallet beneath the deck boards. Stringer pallets offer two-way fork entry by default (from the ends only), but can be modified for partial four-way entry by adding notches to the stringers. They are less expensive to manufacture than block pallets and easier to repair.
Stretch Wrap (Stretch Film)
A highly stretchable plastic film (typically LLDPE — Linear Low-Density Polyethylene) wrapped around palletized loads to unitize and stabilize them during storage and transit. Stretch wrap can be applied manually with a hand dispenser or automatically with a stretch wrapping machine. Proper stretch wrapping technique starts at the base, overlaps each layer by 50%, and anchors the film to the pallet itself to prevent the load from sliding off the deck.
Top Cap
A protective cover placed on top of a palletized load before stretch wrapping to provide additional protection from dust, rain, and vertical impact. Top caps are typically made from corrugated fiberboard or rigid plastic and distribute the compressive force of stacked loads, reducing damage to the products on the top layer.
Two-Way Entry
A pallet design that allows forklifts and pallet jacks to enter from only two opposite sides — the ends. Standard stringer pallets without notches are two-way entry pallets. Two-way entry is adequate for simple point-to-point shipping but can slow operations in busy warehouses where pallets must be approached from multiple directions.
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10 terms
Unit Load
A single, consolidated grouping of individual packages or items assembled on a pallet and secured as one unit for handling and transportation. Creating unit loads is the fundamental purpose of pallets — they transform many small items into one large item that can be efficiently moved, stored, stacked, and tracked through the supply chain. Proper unit load design considers product dimensions, weight, fragility, and the pallet's load capacity.
Unitizing
The process of assembling individual products or packages into a single unit load on a pallet, using stretch wrap, banding, shrink wrap, or adhesive to hold everything together. Proper unitizing prevents load shift during transit, reduces handling damage, speeds loading and unloading, and enables efficient warehouse operations. The goal is to create a load that behaves as a single, stable entity.
Used Pallet
Any pallet that has completed at least one shipping or storage cycle. Used pallets represent the vast majority of pallets in circulation at any given time, with over 70% of all pallets in use in the United States being previously used. Used pallets are graded (A, B, C, Economy) based on their condition and are significantly less expensive than new pallets. Fresno Pallets is a leading supplier of inspected, graded used pallets in the Central Valley.
Wane
The presence of bark or the absence of wood along the edge or corner of a board, resulting from the original curvature of the tree trunk. Wane is a common characteristic of economy-grade lumber and is generally acceptable on non-critical pallet components. However, excessive wane reduces the board's effective width and strength, and heavily waned boards should not be used for lead boards or stringer components.
Waterfall Edge
A rounded or convex profile along the top edges of deck boards, created either intentionally during manufacturing or naturally through wear. Waterfall edges on the leading deck boards can assist with fork entry and reduce damage to products and shrink wrap that might catch on sharp corners.
Weight Capacity
The maximum load a pallet can safely support, expressed in three categories: static (on a flat floor, not moving), dynamic (being transported by a forklift), and racking (supported only at the edges on rack beams). Weight capacity depends on pallet construction, wood species, moisture content, fastener type, and load distribution. Always select pallets with a capacity rating that exceeds your actual load by a safety margin of at least 20%.
Whitewood Pallet
An industry term for a standard, unbranded wood pallet that is not part of any pooling system (as opposed to CHEP blue or PECO red pallets). Whitewood pallets are purchased outright by the user and can be freely sold, traded, recycled, or disposed of. The term derives from the natural light color of freshly cut softwood lumber, though whitewood pallets may be made from any wood species.
Wing Pallet
A pallet where the deck boards extend beyond the outer stringers or blocks, creating wings or overhangs on two or four sides. Wing pallets provide a larger load-bearing surface than the stringer framework alone, which can be useful for oversized products. However, the overhanging wings are susceptible to damage during handling and are not compatible with tight-fit racking systems or automated conveyor operations.
Wood Packaging Material (WPM)
Any wood or wood product used in packaging, supporting, or securing cargo for international transport, including pallets, crates, dunnage, skids, and cable drums. WPM is regulated under ISPM-15 because solid wood can harbor invasive insects and plant diseases. Processed wood products such as plywood, oriented strand board (OSB), and presswood are generally exempt from ISPM-15 because their manufacturing processes eliminate pest risks.
Yard Audit
A periodic physical count and condition assessment of pallets stored in a facility's yard or warehouse. Yard audits help organizations track pallet inventory, identify damaged units that need repair or disposal, detect theft or loss, and maintain accurate cost accounting. Best practice is to conduct yard audits at least monthly, with more frequent counts for high-volume operations.
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Industry Terms Defined
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