IBM Power 720 Overview page 54

The vertical distance between the mounting holes must consist of sets of three holes
spaced (from bottom to top) 15.9 mm (0.625 in.), 15.9 mm (0.625 in.), and 12.67 mm
(0.5 in.) on center, making each three-hole set of vertical hole spacing 44.45 mm (1.75 in.)
apart on center. Rail-mounting holes must be 7.1 mm ± 0.1 mm (0.28 in. ± 0.004 in.) in
diameter. Figure 1-14 shows the top front specification dimensions.
Figure 1-14 Rack specification dimensions, top front view
40
IBM Power 720 and 740 Technical Overview and Introduction
6.75mm min
15.9mm
15.9mm
12.7mm
15.9mm
15.9mm
12.7mm
Hole Diameter =
7.1 +/- 0.1mm
Rack Mounting Holes Center-to-Center
Top Front of Rack
Top Front of Rack
6.75mm min
15.9mm
15.9mm
12.7mm
15.9mm
15.9mm
12.7mm
450 +/- 0.75mm
Rack Front Opening
465 +/- 0.8mm