Holes are grouped in sets of three, with each group representing one Rack Unit, commonly called 1U. The spacing is measured center-hole to center-hole and remains consistent whether the rack has square or round mounting holes. Our 4-hole rail design gives your gear 1/2RU vertical spacing for improved ventilation in your 19-inch rack. It defines the. A rack unit (abbreviated U or RU) is a unit of measure defined as 13⁄4 inches (44. It is most frequently used as a measurement of the overall height of 19-inch and 23-inch rack frames, as well as the height of equipment that mounts in these frames, whereby the height of the frame or. U (rack unit, RU) is a unit of equipment height in a 19" rack. Important: U describes height only, but a server's real "capabilities" are also determined by chassis depth, internal layout, airflow, rails, power, and expansion (PCIe/risers, NVMe. Portable 19-inch racks filled with audio processing outboard gear are a common sight at concerts with amplified sound. The 19 inch. You'll get the precise, standardized physical dimensions of a 1U rack unit — 1. 6 mm) in width — plus critical context on mounting hole spacing, usable depth variance (typically 17–21″), and why real-world 1U gear is often manufactured at 1.
