c. Mortise Locks. Mortise locks (Figure 160) are used mainly on
front or outside doors for high security. The present trend is away
from using mortise locks because of the difficulty and time required
to install them.
d. Dead Bolts. Dead Bolts are used where added security is
needed. They are constructed of very hard steel. Figure 161 shows
a combination dead bolt and combination dead bolt and latch.
Dead bolt locks