washers are placed between the standoff and the motherboard and between
the motherboard and the screw. This keeps the metal-edged mounting hole from
contacting the screw and standoff and prevents it from shorting the board.
Fixed mounting hardware There are cases that already have their mounting
hardware fixed in place—that is, soldered or welded—to match the mounting
holes of a motherboard of the same form factor as the case. This is intended to
save you time, but if you ever want to move to another form factor motherboard,
you’ll need a new case.(^366) PC Hardware: A Beginner’s Guide
Figure 15-22. The type of plastic standoffs used to mount a motherboard in the case