ANSI MH16.1 is the dominant US standard for pallet rack design and load capacity.
Detailed Definition
ANSI MH16.1, Specification for the Design, Testing and Utilization of Industrial Steel Storage Racks, is published by the Rack Manufacturers Institute (RMI). It sets design methods and loads for selective, drive-in, push-back, flow and other steel storage racks, including column and beam design, beam-to-column connections, base plates and anchors, seismic design, and load testing of components. It also addresses rack use, such as load capacity plaques. Building codes in the US commonly reference it for storage rack design.
What MH16.1 covers and what it does not
MH16.1 governs the rack structure. It does not rate the pallets placed on the rack. A rack beam may be rated for a heavy load while the pallet spanning those beams is the weak point. Pallet strength under racked support is evaluated separately, for example with the racking tests in ASTM D1185 or ISO 8611, or with pallet design software.
One commonly cited MH16.1 limit is beam deflection at rated load of not more than the span divided by 180.
Using MH16.1 in practice
- Keep the rack manufacturer's load capacity plaques posted and readable.
- Do not change beam elevations without checking the effect on upright capacity.
- Use components from the same manufacturer unless an engineer approves the mix.
- Have damaged uprights and beams evaluated and repaired or replaced.
- Confirm seismic design and anchoring for your location with the local building department.
OSHA has no rack-specific standard, but storage must be stable and secure under 29 CFR 1910.176.
Where to get the standard
The specification is available from RMI, which also publishes related guidance on rack inspection and safety. Rack dealers and engineers use it for permits and capacity calculations, so ask for the edition used when a rack is designed or reconfigured.
Authoritative Sources
- Rack Manufacturers Institute (RMI): the MHI subsidiary that publishes ANSI MH16.1 pallet rack design and load capacity standards.
- Material Handling Institute (MHI): the largest US trade association for material handling, logistics, and supply chain technologies.
- ASTM International (ASTM): the global standards body that publishes ASTM D1185 (Standard Test Methods for Pallets and Related Structures Employed in Materials Handling and Shipping).
Related Glossary Terms
Frequently Asked Questions
Is ANSI MH16.1 required by law?
It is a voluntary consensus standard, but building codes used in many US jurisdictions reference it for storage rack design, which can make it effectively required for permits. OSHA does not have a rack standard, though it can cite unsafe storage under its general requirements. Ask your local building authority which edition applies.
Does an MH16.1 rack rating tell me my pallet is safe?
No. The rack rating covers beams, uprights and connections. A pallet spanning the beams can fail at a lower load, especially when racked across its length with no deck supports. Check the pallet's racked capacity separately for the actual pallet design and orientation.