1-15. Locks and Striker Plates. The three general types of door locks
are: the tubular, the cylindrical, and the mortise lock. Deadbolt
and rim locks can be installed to provide additional security.
a. Tubular Locks. Tubular locks have all the advantages of
mortise locks, but are much easier to install because they only need
bored holes. They are used mainly for interior doors for bedrooms,
bathrooms, passages, and closets. They are available with a key
tumbler lock in the knob on the outside of the door or with a turn
button or push button on the inside. Figure 158 shows a tubular
b. Cylindrical Locks. Cylindrical locks (Figure 159) are
basically the same as the tubular type. The cylindrical lock is a
sturdy, heavyduty, and stronger lock, which is used on exterior
doors for maximum security.