Nortel Passport 15000 Hardware Installation And Maintenance page 510

510 Chapter 17 Hardware procedures
241-1501-240 5.2S2
4 While a helper holds the panel while the top 2 screws are fastened. While
still holding the panel, loosely fasten a thread-forming 10-mm (3/8-in.)
hex-head screw through each of the 2 holes so that the panel is
supported.
5 Align and loosely fasten a screw through the 6 remaining panel holes,
starting at a bottom corner.
6 Tighten all screws to snug plus a 1/4 turn.