Table 2-5. Detail Dimensions of Typical Wide-Flange Shapes
threads per inch than the NC series as shown in table
2-19. CONNECTIONS
2-6.
The building of any structure consists of joining
component parts. The parts are connected with bolts
and nuts or by welding.
a. Bolts and Nuts. In general, data concerning
bolt dimensions is obtained from standard tables.
However, bolts and nuts are seldom shown on detail
drawings. Bolt and nut connection is the primary
type used in the field. Bolts and nuts are used
because they require less skill and less tools. On
assembly drawings, where bolts and nuts are
encountered
most
frequently,
approximate
dimensions are adequate. Thread specifications are
given in a note. The format or order of the
Figure 2-30. Thread specification note.
specification note is in accordance with accepted
standards. Figure 2-30 indicates the order of the
b. Rivets.
Rivets are rarely used as
specifications note for a typical American Standard
connectors in the field. Some members may be
thread and explains interpretation. Referring to
fabricated in the shop with rivet connectors and then
figure 2-30, you will see that the first number of the
brought to the field for bolt and nut or weld
note (3/4) denotes the nominal size of the major
connecting. All holes for rivets are punched or
diameter and the number following the first dash (10)
drilled in the fabricating shop whether the rivets are
indicates that there are 10 threads per inch. Also
to be driven in the shop or in the field. Rivets that
apparent is that the letters NC indicate the thread
will be placed and driven in the shop to connect
series (National Coarse) and the last number (2) the
structural members are indicated on the print by a
class of fit (class of thread and tolerance). The letters
shop rivet symbol (○). Structural members to be
LH following the last number designate left-hand
threads, while notes without LH designate right-hand
connected at the job site are indicated on the print by
threads. The most widely used thread-series are the
a field rivet symbol (●). Conventional shop and
American Standard National Coarse (NC) and
field
National Fine (NF). The NF series have more
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