This is a crucial question. As of 2025, , but it is supplemented .
: Must conform to specific dimensional requirements for thickness and hole alignment to ensure a "secure and snug fit" for mounting pins and screws. Hardware Compatibility
The distance between the center of the mounting holes on the left and right rails is specified at 18.312 inches (465.1 mm) .
The standard defines several fundamental measurements for data center and IT infrastructure:
The EIA (now merged into ANSI) stepped in to create a unified standard. The most famous and widely adopted revision is , published in the early 1990s.
With that PDF in hand, you can confidently design, drill, mount, and manage any server rack built in the last 30 years. That is the power of a good standard—and now you know exactly how to access it.
