What is pallet racking?
Also called: pallet rack, warehouse racking, storage rack
Pallet racking is a steel storage structure of upright frames and horizontal beams that holds loaded pallets in levels above the floor. The pallet usually spans the gap between two beams, so its racking load rating, not its floor rating, governs.
In depth: Pallet racking and deflection: rack spans, direction and sag limits
Pallet racking stores unit loads vertically. Upright frames hold pairs of horizontal rack beams, and the pallet sits on the beams with open space beneath it.
Common rack types
| Type | Depth | Access | How the pallet is supported |
|---|---|---|---|
| Selective | 1 deep (2 for double-deep) | Every pallet | Front and rear beams |
| Drive-in | Many deep | Last in, first out | Rails under two sides |
| Push-back | Several deep | Last in, first out | Nested carts on rails |
| Pallet flow | Many deep | First in, first out | Gravity rollers |
| Automated storage | Varies | Machine | Rails, shuttles, conveyors |
Why it matters for pallet design
In a rack, the pallet works as a beam across an open span. That makes its racking load and deflection the governing numbers. Which direction it spans (across length or across width) changes which members carry the load.
On a spec sheet or RFQ
Give the rack type, the pallet orientation, beam span or spacing, number of beams, any wire decking, and how long pallets stay loaded. The racking and deflection guide covers the calculation inputs.
Common confusions
Rack capacity (what the beams and frames hold) is separate from pallet racking capacity (what the pallet holds while spanning them). Both must be adequate.
Frequently asked questions
What are the main types of pallet racking?
Selective racking is the most common. Drive-in, push-back and pallet flow racking store pallets several deep for higher density, and automated systems use shuttles or cranes. Each supports the pallet differently.
Can any pallet go in a pallet rack?
No. The pallet must carry its load while spanning the beams, within a deflection limit. Nestable plastic pallets and many presswood and paper pallets are not rated for racking.
Which way should a 48 × 40 pallet sit in a selective rack?
In North America it usually sits with the 40 in face on the beams and the 48 in length spanning front to back, so it is racked across its length. Check the rack design and the pallet's rating for that direction.
Related
- GuidesPallet racking and deflection: rack spans, direction and sag limitsIn a rack a pallet spans between two beams with nothing underneath, so it bends. Racked across the length (stringers span about 40 to 44 in on a 48 in pallet) is usually stiffer than across the width (deckboards span about 36 in). Common deflection limits are about 2% of span, or 0.5 in or less for automated storage.
- GlossarySelective rackSelective rack is the most common pallet racking: one pallet deep from each aisle, so any pallet can be picked without moving another. The pallet rests on a front and rear beam and spans the gap between them.
- GlossaryRacking loadRacking load is the weight a pallet can safely carry while it spans the gap between rack beams with no support underneath. It is usually the lowest of a pallet's ratings and depends on the span, the direction racked and the number of beams.
- GlossaryRack beamA rack beam is the horizontal steel member that spans between upright frames in pallet racking and carries the pallets. The distance between the front and rear beams sets the pallet's unsupported span.
- GlossaryDrive-in rackA drive-in rack is high-density racking where the forklift drives into a lane and places pallets many deep on continuous rails along each side. The pallet is supported only along two edges, so its capacity across the unsupported direction governs.
- TypesRackable plastic pallet: runners, reinforcement and racking ratingsA rackable plastic pallet is designed to sit in open-beam racking with nothing underneath. It has runners (3, 5 or 6) or a perimeter or cruciform base, often with steel reinforcement. Racking ratings for 48 × 40 in models are typically about 1,500–4,400 lb, valid only at the tested span and orientation.
More in Handling and storage
- GlossaryAutomated storageAutomated storage, often called AS/RS (automated storage and retrieval system), stores and retrieves pallets with stacker cranes, shuttles and conveyors instead of forklift drivers. It needs pallets with tight dimensional tolerances, low deflection (often 0.5 in, 13 mm, or less) and sound bottom decks.
- GlossaryBlock stackingBlock stacking is storing unit loads directly on top of one another on the warehouse floor, in rows and columns, with no racking. The bottom pallet and the packaging carry the whole stack, so static load and box compression strength limit the height.
- GlossaryConveyorA pallet conveyor moves loaded pallets on driven rollers or chains instead of a forklift. The pallet's bottom deck is the running surface, so the orientation of bottom boards, flatness, deflection and condition decide whether it runs reliably.
- GlossaryEdge protectorAn edge protector, or corner board, is an L-shaped strip of laminated paperboard, plastic or other material placed on the vertical or top edges of a unit load. It spreads strapping and stretch wrap pressure, protects case corners, and can add vertical stacking strength.
- GlossaryFork tinesFork tines are the two steel arms on a forklift or pallet jack that slide into a pallet's openings to lift it. Their width, thickness, length and spacing set the minimum size of the pallet's openings and affect its dynamic load rating.
- GlossaryPallet dispenserA pallet dispenser is a machine that holds a stack of empty pallets and releases them one at a time, usually onto a conveyor feeding a palletizer. It needs pallets with consistent dimensions, flat decks and sound bottom boards.
Last reviewed 2026-09-24. 232 words.