Deductions for Holes:

(a) Deductions for rivet holes are made as per Eqs. (a) and (b).

(b) The field to be deducted shall be the sum of the sectional areas of the maximum number of holes in any cross-section at right angles to the direction of stress in the members for all axially loaded tension members.

(c) While bolt or rivet holes are staggererd, the area to be deducted shall be the sum of the sectional areas of all holes in a chain of line s² t/4g progressively across the member, less for every line extending between holes at other than right angles to the direction of stress while s, g and t are respectively the staggered gauge, pitch, and thickness related with the line under consideration (Figure (a)). The chain of lines shall be chosen to produce maximum such deduction. Thus, from Figure (a), we get

Deduction = Sum of sectional area of holes B, C, D +s₁² t/4 g₁ + s₂² t/4 g₂.

(d) For non-planar sections such as angles with holes in legs, the gauge, (g), shall be the distance along the centre of the thickness of the section between whole centers as shown in Figure (b).

(a) Plate          (b) Angle

Figure