Nails, Screws, Bolts, and Other Fasteners - Carpenter's and Builder's Math, Plans, and Specifications - page 39

instead. All this amounts to is a toggle bolt without a head on the
screw. This is so that the screw can be turned into the female machine
threads in the device to be mounted. A toggle stud will not bear as
much weight as a hanger bolt, but it should be adequate for a small
to medium-size flowerpot and hanger. It is used the same as a toggle
bolt.
Framing Fasteners
Framing fasteners are stamped metal pieces (16 or 18 gauge) with
predrilled nail (or screw) holes. You set the fastener between the
pieces and drive the nails through the holes to lock the members to-
gether. The result is a very strong connection. It should be noted that
not all building codes accept them, so their use should be checked
out beforehand (see Figure 1-32).
Summary
Nails are the carpenter's most useful fastener. Many nail types and
sizes are available to meet the demands of the industry. On any kind
of construction work, an important consideration is the type and
size of nails to use.
An important factor in selecting nails is size. Long, thin nails will
break at the joints of the lumber. Short, thick nails will work loose
quickly. The kind of wood is a big factor in determining the size of
nail to use.
Wood screws are often used in carpentry because of their advan-
tage over nails in strength. They are used in installing various types
of building hardware because of their great resistance to pulling out
and because they are more or less readily removed in case of repairs
or alterations.
There are generally three standard types of screw heads: the flat
countersunk head, the round head, and the oval head. All of these
can be obtained in crossed slot, single straight slot, or Phillips slot.
Lag screws or lag bolts are heavy-duty wood screws that are
provided with a square or hexagonal head so that they are installed
with a wrench. These are large, heavy screws that are used where
great strength is needed, such as when working with heavy timber
and beam installations. Holes are generally bored into the wood
because the diameter of lag screws is large.
A bolt is generally regarded as a rod having a head at one end and
a threaded portion on the other to receive a nut. The nut is usually
considered as forming a part of the bolt. Bolts are used to connect
two or more pieces of material when a very strong connection is
required.