The vertical structural component of a pallet rack consisting of two columns and bracing.
Detailed Definition
An upright frame is the vertical end section of a pallet rack: two steel columns joined by horizontal and diagonal bracing, with base plates at the bottom that are anchored to the floor. Beams connect pairs of frames to form storage bays. A frame's rated capacity depends on column size, bracing, height and especially the vertical distance between beam levels, so the rating applies only to the beam layout it was calculated for.
Sizing upright frames to the pallet
Frame depth is chosen so pallets overhang the beams by a small, even amount at front and back. A common example is a 42-inch-deep frame for 48-inch-deep pallets, which leaves about 3 inches of overhang on each side. Frame height follows from the number of beam levels, load heights, clearances, and the building's ceiling and sprinkler limits. Column size and bracing pattern are set by the rack designer from the loads on each level.
Capacity, standards and load plaques
In the US, industrial steel storage rack design is covered by ANSI MH16.1, the RMI specification. Capacity is normally posted on load plaques at the rack. Moving beams, adding levels or storing heavier loads can reduce frame capacity, so changes should be reviewed by the rack manufacturer or a qualified engineer. In seismic regions, frame design and anchoring must also meet the local building code.
Inspecting upright frames
Look for bent or twisted columns, damaged or missing braces, loose or missing anchors and damaged base plates. Columns at aisle ends and corners take most forklift impacts, which is why column protectors and end-of-aisle guards are used. Damaged frames should be unloaded and assessed under the site's rack damage procedure, following the manufacturer's guidance.
Related Glossary Terms
Frequently Asked Questions
Can I move the beam levels on an upright frame?
Beam levels can usually be adjusted because beams hook into punched holes in the columns, but changes affect capacity. Raising the first beam level or increasing the gap between levels lengthens the unsupported column and can reduce the frame's rated capacity. Unload the bay first, follow the manufacturer's instructions, and confirm the new layout against its capacity information before reloading.
Are upright frames from different manufacturers interchangeable?
Usually not safely. Hole patterns, beam connectors, column profiles and capacity tables vary by manufacturer and product line. Mixing components can leave beams poorly engaged or create an untested combination with unknown capacity. If you must combine used rack from different sources, have the rack manufacturer or a qualified engineer evaluate and rate the configuration before loading it.