IBR boiler riveting: shearing resistance per pitch length in double shear Let d = rivet diameter, τ = allowable shear stress, and n = number of rivets per pitch length. According to I.B.R., determine the shearing resistance required to shear off the rivets (double shear). Choose the correct expression.

Given• Boiler joint design per I.B.R. (Indian Boiler Regulations).• Double-shear condition; n rivets per pitch length.

Concept/ApproachPer I.B.R. empirical provisions, the shearing resistance in single shear is taken as 0.9375 · d^2 · τ · n (using an effective shear area factor). For double shear, multiply by 2:

Shearing resistance (double shear) = 2 × 0.9375 · d^2 · τ · n = 1.875 · d^2 · τ · n

Common pitfallDo not confuse with the theoretical area πd^2/4; I.B.R. uses codified effective factors for boiler riveting.

Final Answer1.875 · d^2 · τ · n