The ABC’s of Storage Rack – Pallet Rack Glossary of Industry Terms

Understanding the different components, processes and standards associated with pallet racking can help you make an informed decision about systems integration within your facility. To aid in that effort, Warehouse Optimizers, Inc. (WOI) has developed a comprehensive glossary of pallet rack terms. This tool is meant to provide a comprehension framework and consistent vocabulary related to storage racking. We believe in empowering our clients to make the most informed choice and encourage you to call our experienced and qualified staff should you have any questions about this versatile and commonly used storage solution.

Pallet Racking Terms – Components, Accessories, Systems and Processes

• Automated Storage and Retrieval Systems (ASRS) – Pallet racking integrated with automated systems, conveyance and/or vehicles (AGVS). ASRS systems include a variety of computer-controlled systems for automatically placing and retrieving loads from predetermined storage locations.
• Allowable Strength – Maximum degree of stress that is allowed to be placed on a pallet rack.
• Applicable Code – Code that is generated and enforced by a local building department to classify a rack structure.
• Angle Deflector – Bolted-on or welded components implemented to offset impact in vulnerable areas of the rack.
• Beam-Locking Device – Mechanism that secures beam to the column of the rack.
• Beam – The front and back shelf supports that hold the weight of the load and transfer the load to the upright frames.
• Bay (Pallet Rack Bay) – Between upright openings in a pallet racking system where inventory is stored.
• Cantilever Racking – Rack designed using horizontal arms vs flat shelving to store awkwardly shaped, linear, or bulky items, such as steel, conduit, piping, construction equipment and utility materials.
• Carton Flow Racking – Racking system that supports wheeled or roller case-flow lanes placed between the front and rear beams. Lanes are positioned at a slight angle to flow inventory from the rear of the system to the front using gravity to propel cases, cartons, or totes.
• Case Flow Racking – Also known as carton flow rack, see description above.
• Cement Frame Anchor – Anchors that attach rack uprights to the cement floor.
• Corrugated Decking – Sometimes called B-Deck, corrugated decking creates a solid surface shelf between support beams usually for non-palletized item storage. Provides seamless and smooth loading and unloading.
• Diagonal Bracing – Member placed at an adjacent angle to another to add strength to the upright of the pallet racking system.
• Double-Deep Pallet Rack – A 2-pallet deep selective rack system. Must use a deep-reach forklift to access the rear pallet.
• Drive-in / Drive-through rack – Rack storage systems comprising uprights and horizontal arms equipped with load rails. Pallets are placed on the rails vs in a rack bay of a standard system allowing deep-lane storage vs horizontal. Drive-in systems use a single aisle for loading and unloading while drive-through allows access from a front and rear aisle.
• Drum Coil Bed – Beds that are built to store drums on a pallet racking shelf. Ideal for high-volume liquid storage.
• Flue space – The space between two back-to-back rack systems that must be kept open to allow fires to vent vertically and the water from sprinkler systems to reach the fire’s source.
• Column Guard – Guards designed to protect rack uprights  from collision impact. Guards are either bolted to the front of the rack or anchored to the floor.
•  Floor Guard – Guards or angles that are anchored to the floor and designed to protect the aisle faces of the racking systems in high-traffic areas.
• Upright (Upright Frame) – Two columns connected by a series of struts welded or bolted into place to give the upright its structure for the purposes of supporting the pallet racking system.
• Fork Entry Bar – Pallet rack accessories that allow forklift forks to slide underneath flat stock loads stored in the rack system.
• Kickplate – Plate installed at the edge of an elevated floor to prevent loose items from sliding off the edge.
• Load Buckling – Point at which racking buckles or deforms under load pressure.
• M & V Dividers – Dividers that separate products stored upright within a pallet rack system.
• Movable Shelf Rack – Shelves within a pallet rack system that can be configured to accommodate different-sized products.
• Pallet flow rack – A gravity flow full pallet storage system using wheels or rollers to propel inventory from a rear load aisle to a forward pick aisle. Lanes are installed with a slight pitch to permit gravity to take over. Typically used for 2-5 pallets deep but can be configured for deep-lane storage. Typical flow rack is first-in/first-out (FIFO).
• Pallet Supports – Supports that extend between the shelf beams to provide a safeguard for misaligned pallets. Supports give the forklift operator time to properly align the pallet preventing it from falling. Pallets are not to be stored on the supports. Pallets rest on the front and rear beams or decking if available.
• Push-back rack – A pallet storage system using enveloping wheeled carts or rollers set on tracks installed with a slight pitch. This system is loaded and retrieved using a single aisle. The pallets are placed on the cart and pushed back as each new pallet is loaded. Rear pallets flow forward as the front pallet is picked. Usually used for storing 3-4 pallets per lane. Typical push back systems are first-n/last-out (FILO).
• Rack Supported Platforms – Pallet racking can be designed as a support for mezzanine and work platform structures.
• Rack Supported Buildings – Pallet racking can be designed to support a building structure.
• RMI – RMI develops American National Standards for industrial steel storage racks and welded wire rack decking adopted by most building codes.
• Roll Form Rack – Racking that is roll formed into uprights, beams, and components.
• Row End Protectors – Steel guards that run along the aisle-side bottom of the frame to protect racks from PIV and forklift collision damage in high-traffic areas.
• Row Spacers – Devices placed between uprights to stabilize back-to-back rack system configurations. They generally bolt onto each upright and join the uprights together in the flue space.
• Safety Beam Clip – Clips used to secure the connection of cross-beams to the uprights and prevent beams from becoming loose or detached. These are in addition to the beam connectors.
• Safety Netting – Engineered nylon or plastic mesh affixed to the rear of a pallet rack system  to safeguard the area below from falling debris. Netting is often held in place by steel cable.
• Seismic Engineering – Special rack engineering requirements for each different location depending on the geography of that area.
• Selective Pallet Rack– A rack system designed using vertical upright frames and horizontal shelf beams to store one pallet deep with multiple units high and wide. Most common storage rack system. Systems are often configured back to back (and tied with row spacers) to maximize floor space and consolidate aisles.
• Shim – Steel plates that match the upright base plate are often stacked to level the rack and accommodate for uneven concrete slabs.
• Splice Channel – Assembly and hardware used to increase height of frame uprights when needed by connecting two posts together.
• Structural Rack – Racking that is designed and manufactured using structural steel uprights, beams, and components.  Typical use in heavy duty applications.
• Teardrop Upright – The most common and universal hole pattern in the upright.
• Wall Tie – Ties connected to bolts and frame uprights that secure the racking system to an adjacent wall for stabilization.
• Wire Decking – Metal mesh secured to the front and rear beams to form a flat surface for storing pallets and non-palletized inventory safely. Design allows for good air circulation and water flow from sprinkler systems.

Want to Know More about Pallet Racking?

Should you have any additional questions about pallet rack products, accessories or concepts, WOI. is ready to help. Safety is one of our focus points with our 5 Step Total Satisfaction Experience™ you are guaranteed that we wil 1. listen to your needs, 2. execute your project with special attention to your unique application, 3. stick to project timelines, 4. ensure a safe environment, and 5. pay close attention to the appearance of the finished product. The WOI team will walk you through each stage of the process and provide expert customer service to deliver great results and peace of mind. Contact a member of our team today and let’s chat or Zoom. Call (865) 540-4004 for a prompt response. We proudly serve customers in Tennessee, Alabama, and throughout the Southeast.