Coming to Terms with the Material Handling Word Soup

Apex Shares Helpful Pallet Rack Glossary

While no business is immune to confusion and mistakes due to miscommunication, we find that common terms and phrases are anything but common in the material handling & warehousing sector. Given that the average facility has potentially millions of moving parts, it’s critical that your team rely on a single set of terms to ensure successful communication which leads to increased safety, efficiency and ultimately cost savings.

Since Apex is heavily immersed in pallet rack system design and warehouse safety training, we thought we’d share the Glossary of Terms that we use to train our team. We’ve also included useful links to product pages and blogs should members of your team need training or a refresh of common warehousing systems terms and abbreviations.

Please let us know if you have regularly used terms that you think would be good to add to our Glossary. We welcome your feedback. If you’d like to discuss system design or operation to solve your facility or inventory challenges, give us a call… we’re trained and always ready to help!

Glossary of Terms

Back to Back Rack: Refers to formation where 2 pallet rack uprights are installed back to back. The bays of rack are “tied” together using row spacers. (See also: Deep-Reach (below))

Bay: Common term referring to a section of rack or shelving where a pallet, for example, would be stored.

Box Beams: A type of shelf beam created without an inset step… has four flat sides like a box.

Carton Flow: Pallet rack system configured to accommodate deep-lane storage of cartons, totes and eaches. A gravity flow system relies on slightly inclined beds of wheels or rollers to glide inventory from load end to pick end.

Cantilever Rack: Storage rack system designed for storing long items, such as lumber, building products, furniture and even wire rolls. Rack is distinguished by protruding arms attached to the rack column where items are placed for storage.

Column: A column can be the front or rear vertical structure for an upright. It can also be the independent vertical support (mono-post) in a pushback, drive-thru, pallet flow, or pallet shuttle upright line. A column can be manufactured in a variety of steel thickness and in both structural and roll-formed based upon load requirement and usage. Holes or punches run the length of the column at standard intervals where the beams will ultimately be connected.

Connectors: Roll-formed beams are designed to clip or snap into the columns depending on the specific punching pattern of the column. Safety clip to column options include clip, snap or bolt and will vary based upon column punching.

Deep-Reach Rack: Refers to pallet rack layout of back to back rows of 2-deep selective rack. Double-deep selective rack requires the use of a double-deep reach truck. (See outrigger damage pg. 38.)

Drive-In Rack: Pallet racking designed to allow forklifts to enter into the individual bays of the rack to load and pick palletized material. A popular high-density storage solution.

FIFO: Inventory processing acronym for First-In/First-Out describing the SKU storage method used.  FIFO product enters the rack from the rear and removal is done from the front so that the first product loaded is the first one to picked.

LIFO: Inventory processing acronym for Last-In/First-Out describing the SKU storage method used. The first product picked is the last product that was stored.

Pallet Flow: Pallet rack system using slightly inclined wheeled rails or rollers that allow pallets to move smoothly along a sloped plane. A type of gravity flow or dynamic flow rack system, pallet flow often has accessories such as brakes, stops and guides to ensure safe, efficient pallet movement.

Pallet Rack: Material handling storage method designed to store materials on pallets or “skids”. As this guide explains, several options of pallet racking exist with the ultimate purpose of storing palletized inventory in horizontal rows and on multiple levels.

Pick Modules: Multi-level, complex racking structures designed to facilitate order picking and replenishment storage in a highly condensed and organized footprint. Usually consist of a combination of pallet racking and carton or each pick storage options.

Push Back Rack: Pallet rack fitted with a series of nested rolling carts that sit condensed at the front of the rack then expand back as each top cart is loaded with a pallet. Carts move on slight incline so that they move smoothly back when pushed by the forklift for loading and glide gently forward as front pallets are extracted.

Rack: Describes the steel storage structure of uprights and beams designed to store pallets or other inventory items.

Roll-Formed Rack: A method for producing the steel storage rack components; uprights, beams, struts.

Row Spacers: Used to connect two back to back upright rack systems. Row spacers ensure that the rows are kept straight and can provide strength and stability to the rack structure.

Pallet Supports: Metal crossbars that assure proper load balance and prevent misplaced pallets from temporarily falling through. Pallet supports are often an alternative to wire decks.

Selective Rack: Single-deep, static pallet racking that allows for good vertical space use. It is the most cost-effective storage solution.

Shelf Beam: The purpose of the shelf beam is to connect to the upright columns to form a shelf for the pallet to be placed upon. Box, top, and structural channel are the three types of shelf beams.

Shelving: Describes a multi-level storage unit convenient for hand-stored products as opposed to rack which is typically loaded via a forklift or other mechanical equipment.

SKU: An acronym for Stock Keeping Unit which identifies an individual product in inventory.

Step Beams: A type of shelf beam that has an inside step along the top inside edge on which to place pallet supports or wire decks

Structural Rack: Pallet rack systems where uprights and beams are manufactured from hot rolled channel steel and structural angle, then welded together to support greater weight-bearing capacity.  Beams and columns of a structural system are bolted together. Structural pallet rack can also be designed into the structure of the building itself, so that the upright columns are simultaneously used to support the roof of the storage facility, in which case the structural pallet rack uprights replace the storage building’s vertical support I-beams.

Uprights: Uprights are typically constructed of two columns connected by horizontal and vertical struts and anchored to the floor via the baseplate.

VNA: Acronym for Very Narrow Aisle. In a VNA system, pallet racks are loaded and unloaded using a side-loading fork truck; therefore, the racks can be positioned at closer intervals minimizing floor space needed for aisles.

Wire Decks: A common safety feature added to selective pallet rack to prevent pallets or individual products from falling through the rack. Wire decks are placed over or in between the beams to basically form a shelf in the rack bay.