A to Z
| Term | Meaning |
|---|---|
| Adder bay | A bay that shares an upright with the bay beside it: one upright plus beams. See starter bay. |
| Aisle | The space between rows where the truck works. Its width is set by the truck. |
| Anchor | The wedge bolt through a footplate into the slab. Every upright is anchored. |
| AS/RS | Automated storage and retrieval system: a crane or shuttle stores and retrieves loads in a rack without a forklift. |
| Back-to-back | Two rows of rack placed rear to rear with a flue space between, held by row spacers. |
| Base plate | See footplate. |
| Bay | The opening between two uprights; beam length plus one column. |
| Beam | The horizontal member pallets sit on; also load beam, cross beam, step beam, box beam. |
| Beam face | The height of a beam's front wall. It is not the width a pallet bears on. |
| Beam spacing / pitch | The vertical distance between beam levels. It affects frame capacity. |
| Bollard | A floor-anchored post that protects a column or an aisle end from forklifts. |
| Box beam | A beam rolled into a closed rectangle with no step. |
| Bracing | The horizontal and diagonal members between the two columns of an upright. |
| Cantilever rack | Rack with arms on columns and no front posts, for long loads. |
| Capacity | The rated load: per beam pair, per frame (at a given beam spacing), per deck, per arm. |
| Carton flow | Shelving with roller or wheel lanes on an incline; cartons roll to the pick face. |
| Clear height | Floor to the lowest obstruction overhead. |
| Column | One vertical member of an upright; also post. |
| Column guard / protector | A steel guard around the base of a column. |
| Counterbalance truck | The standard forklift; needs a 12 to 13 ft aisle. |
| Cross beam | See beam. |
| Deck | What sits on a beam pair: wire deck, solid deck, or pallet supports. |
| Double-deep | Rack two pallets deep from one aisle, worked by a double-deep reach truck. Not the same as back-to-back rows, where each row has its own aisle. |
| Drive-in / drive-through | Rack the truck drives into, pallets on rails; LIFO for drive-in, FIFO for drive-through. |
| Flue space | The gap between loads (transverse) and between rows (longitudinal) for sprinkler water, usually 6". |
| Footplate | The plate welded to the bottom of a column, anchored to the floor. |
| Frame | See upright. |
| Gauge | Sheet steel thickness; lower is thicker. 14 gauge is standard roll-formed rack. |
| High-piled storage | Fire-code term for storage over 12 ft (or 6 ft for high-hazard goods). Permits and fire protection depend on area, commodity and the local code. |
| Keystone | A rack style with trapezoid holes and hook-on beams; also Republic. |
| Lane | One pallet-wide path in a deep system (push-back, drive-in, flow). A bay can hold more than one lane. |
| Level | One pair of beams (an elevated level). Floor storage counts as one more level if you use it. |
| LIFO / FIFO | Last-in-first-out (drive-in, push-back) versus first-in-first-out (pallet flow, drive-through). |
| Load plaque | The sign on the rack stating its capacities; required. |
| Mezzanine | A steel platform that adds a floor; free-standing, rack-supported or shelving-supported. |
| Pallet flow | Lanes of rollers on an incline; pallets roll to the pick end. FIFO. |
| Pallet position | One pallet's spot on a level. |
| Pallet support | A bar between beams under a pallet, used instead of a deck. |
| Pick module | Multi-level structure of carton flow, pallet flow and conveyors for case picking. |
| Push-back | Lanes of nested carts on inclined rails, loaded and picked from the same aisle. LIFO. |
| Rack-supported | A mezzanine or building whose floor or roof is carried by the rack itself. |
| Reach truck | A narrow-aisle truck with a pantograph; 8.5 to 10 ft aisles. |
| RMI | The Rack Manufacturers Institute; its ANSI MH16.1 standard governs rack design. |
| Roll-formed | Rack cold-formed from sheet steel; most use pin or hook connectors, T-bolt uses a bolt. |
| Row | A line of bays. |
| Row spacer | The bar that holds two back-to-back frames at a set gap. |
| Safety lock / clip | The pin or clip that keeps a beam from lifting off the upright. |
| Seismic | Earthquake design; sets frame size, anchors and bracing in many areas. |
| Selective rack | Standard pallet rack with every pallet reachable from the aisle. |
| Shuttle rack | Deep lanes worked by a battery shuttle cart the forklift places in the lane. |
| Starter bay | A complete bay with two uprights and beams; the first in a row. |
| Step beam | A beam with a 1 5/8" step along the inside top edge for decks. |
| Structural rack | Rack made of hot-rolled C-channel, bolted together. |
| Teardrop | The inverted-teardrop slot pattern of the most common rack style. |
| Upright | The vertical end frame: two columns, bracing, footplates. |
| VNA | Very narrow aisle: 5 to 6 ft aisles worked by a turret truck, often wire or rail guided. |
| Waterfall | A wire deck edge that turns down over the beam face. |
| Wire deck | Welded wire mesh on channels laid on a beam pair. |
| Wire guidance | A wire in the floor that steers a VNA truck down the aisle. |
See also how to measure pallet racking and the rack style guide.
