152 Machine Drawing
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d:\N-Design\Des10-1.pm5
dd
0.7 d
1.6 d
Snap head
0.7 d
2d
R = 1.7 D
0.6 d
1.76 d
R = 3.5 d
R
High button
head
Pan head Cone head
0.7 d
1.6 d
d
0.2 d
0.25 d
1.5 d
0.25 d
1.5 d
Flat head Truss head
0.25 d
2d
0.25 d
2d
Flush counter-
sunk head
Round top
countersunk head
dd dd dd
dd dd dd dd
Fig. 10.3 Types of rivet heads
10.4.2 Margin
It is the distance from the edge of the plate to the centre of the nearest rivet. It is usually taken
as 1.5d, where d is the rivet diameter. It is denoted by ‘m’.
10.4.3 Chain Riveting
If the rivets are used along a number of rows such that the rivets in the adjacent rows are
placed directly opposite to each other, it is known as chain riveting (Fig. 10.10).
10.4.4 Zig-Zag Riveting
In a multi-row riveting, if the rivets in the adjacent rows are staggered and are placed in-
between those of the previous row, it is known as zig-zag riveting (Fig. 10.11).
10.4.5 Row Pitch
It is the distance between two adjacent rows of rivets. It is denoted by ‘pr’ and is given by,
pr = 0.8p, for chain riveting pr = 0.6p, for zig-zag riveting.
10.4.6 Diagonal Pitch
This term is usually associated with zig-zag riveting and is denoted by ‘pd’. It is the distance
between the centre of a rivet in a row to the next rivet in the adjacent row.
10.5 Classification of Riveted Joints
Riveted joints may be broadly classified into : structural joints and pressure vessel joints.
10.5.1 Structural Joints
Structural steel frames are made by using rolled steel plates and sections of standard shapes,
as shown in Fig. 10.4.
Figure 10.5 shows an angle joint used to connect two plates at right angle. Here, an
(equal) angle is used to connect the plates, by a single row of rivets. Figure 10.5 also shows the
position of the rivets and other proportions of the joint.
Figure 10.6 shows rolled steel sections, i.e., a column and a beam connected to each
other through riveted joints. Figure 10.7 illustrates one design of a built-up girder, also made
of rolled steel sections. In both the figures, proportions of the joints are also indicated.
