19 inch Rack Strip
19inch Rack Strip has holes arranged vertically in repeating sets of three, with center-to-center separations of 0.5 inches (12.70 mm), 0.625 inches (15.88 mm), 0.625 inches (15.88 mm). The hole pattern repeats every 1.75 inches (44.45 mm). The square holes are meant for cage nuts. Racks are divided into and reffered to as "U", for "unit", 1.75 inches (44.45 mm) in height, within which there are three complete hole pairs in a vertically symmetric pattern, the holes being centered 0.25 inches (6.35 mm), 0.875 inches (22.23 mm), and 1.5 inches (38.10 mm) from the top or bottom of the U. Heights within racks are measured by this unit. Rack-mountable equipment is usually designed to occupy some integer number of U. A rack's mounting consists of two parallel metal 19 inch rack strips The rack strips are each 0.625 inches (15.88 mm) wide, and are separated by a gap of 17.75 inches (450.85 mm), giving an overall rack width of 19 inches (482.60 mm). 19inch rack strip has holes in them at regular intervals, so that each hole is part of a horizontal pair with a center-to-center distance of 18.312 inches (465.12 mm).