Pallet rack can tolerate huge weights, but many people ask, “What is the maximum weight a rack can hold?” The answer to that question is, it depends. While pallet rack capacities will vary by manufacturer, due to the type, quality, and gauge of the steel used, there are many factors that can affect the maximum capacity a particular storage system can withstand. Here’s a look at them:
Before you even get to the pallet rack capacity itself, you must consider the flooring. Soil bearing capacity and the actual flooring in the facility are the first elements in your pallet rack system, and it’s important to know how much weight can your flooring withstand. Because the ground and flooring will ultimately bear the brunt of whatever weight is within the building, it is vital to have a qualified engineer to help plan and prepare for your specific needs. Learn more about site work and flooring here.
Type Of Steel
Your rack capacity is dependent on the type of steel used in the manufacture of the rack. While roll formed rack (cold roll-formed steel) can have high capacities, structural steel rack (hot-rolled) has even higher load capacities. Learn about the differences in roll formed and structural steel here.
Thickness of the Steel
The thickness (gauge) of the steel of both beams and upright frames affects the capacity. The thicker the steel (the lower the number), the more weight it will hold, but note that a stated steel gauge is actually a range of steel thickness, not a fixed number because gauges can vary by up to 18%. This variance doesn’t invalidate the gauge as an indicator of capacity, but it’s important to understand that gauge is not the only factor. It’s also worth noting that when buying used rack, it’s hard to know the gauge if it’s not stamped on the components. Sure, you can measure an upright frame with a caliper, but you would have to cut a beam to measure it, and that would render it useless!
Quality Of The Steel
Different grades of steel will have different tensile and yield strengths, and this will affect pallet rack capacity. It’s generally accepted and recommended by engineers that steel used for pallet rack have a minimum yield strength of 50,000 psi. Most US manufacturers use steel rated from 50,000 to 55,000 psi (All Next Level FlexRack™ has a minimum of 55,000 psi.) Much of the steel coming out of Asia will be less, often as low as 40,000 psi. How can you know what you are getting? Ask for a mill certificate. Learn more about tensile and yield strength here.
Beam Levels and Load Distribution
Just because a pair of beams might have a stated capacity of 5,000 pounds per pair, for example, that doesn’t necessarily mean the level will really hold 5,000 pounds. Beam capacities are based on evenly distributed loads. If your load isn’t evenly distributed, that pair of beams won’t hold 5000 pounds. More beam levels usually mean that the rack has more capacity, although material strength can come into play for very dense and heavy loads.
Vertical Beam Spacing
Vertical Beam Spacing (VBS) is the maximum distance between levels, or the distance from the floor to the first beam level, whichever is greater. An upright frame’s stated capacity is affected by this measurement. If your load weight exceeds what your manufacturer tells you the capacity is, based on your VBS, your rack is in danger of a collapse or other serious accidents. Many people will buy used rack and rely on a guesstimated capacity on the upright frame, without taking VBS into consideration. That’s a recipe for disaster!
The flexible design of Next Level FlexRack™ offers easy bolted assembly with a variety of frame depths and heights up to 47’, plus a range of capacities that allow us to meet both standard and custom warehouse storage application requirements. Our EconoRack™ is the same flexible design, but with less steel, for material and shipping savings for your lighter capacity storage. Connect with us today to get started on designing your warehouse for increased efficiency and profitability.