a) 
In joints, whether lapped or
fitted with butt straps, in which there are more than
one row of rivets and in which there is an equal number
of rivets in each row, the distance between the rows of
rivets shall be not less than
Zigzag riveting :
0.33P + 0.67D = distance
between centre lines of rows (R) 
Eqn. (12) 
Chain riveting :
2D = distance between
centre lines of rows (R) 
Eqn. (13) 

b) 
In joints in which the number
of rivets in the outer rows in onehalf of the number
in each of the inner rows, and in which the inner rows
are chain rivets the distance between the outer rows and
the next rows shall be not less than as required by equations
(12) and (13) whichever is the greater, and the distance
between the rows in which there are the full number of
rivets shall be not less than 2D(R_{1}). 
c) 
In joints in which the number
of rivets in the outer rows in onehalf of the number
in each of the inner rows and in which the inner rows
are zigzag, the distance between the outer rows and the
next rows shall be not less than
0.2P + 1.15D = distance
between centre lines of outer and next rows (R) 
Eqn. (14) 
The distance between the rows in which there are the full
number of rivets shall be not less than :
0.165P + 0.67D = distance
between centre lines of inner rows (R_{1} ) 
Eqn. (15) 
Where
P is the pitch of the rivet in the outer rows.
D is the diameter of the rivet holes in inches or the
mean of the diameter of rivet holes when the distance
to be determined is between two rows of the different
diameters.

d) 
Should the distance between
rows of rivets be less than as prescribed above the plate
percentage determined by equation (2) shall be modified
thus –
100 [ P  ( 2 
actual distance
)
D ]
prescribed distance
= modified plate percentage
P
Eqn. (16)

e) 
In all cases the clear space
between a rivet hole and the edge of a plate shall not
be less than the diameter of the rivet holes, i.e. the
centre of the rivet hole shall be at least 11/2 diameters
distant from the edge of the plate (E);
Provided that if this condition be not observed, the strength
value of the rivet affected shall be reduced in the proportion
of the actual distance between the outer edge of the rivets
and the edge of the plate to the prescribed distance
