Riveting practice: Relative to the rivet shank diameter, how is the plate hole size selected for drilling before riveting?

Introduction / Context:
In riveted joints, holes are made slightly larger than the rivet shank to facilitate insertion, accommodate manufacturing tolerances, and allow proper rivet expansion during setting. Using the correct hole size is essential for accurate strength calculations and reliable fabrication.

Given Data / Assumptions:

• Conventional hot- or cold-driven rivets in metal plates.
• Standard allowances of approximately 0.5 mm to 1.5 mm above shank diameter depending on size and practice.

Concept / Approach:
The hole diameter must exceed the nominal shank diameter to permit insertion and to ensure the rivet upsets properly to fill the hole during driving. Design calculations for net section, rivet shear, and bearing use the hole diameter because it governs the effective areas after drilling/punching and reaming where applicable.

Step-by-Step Solution:

Verification / Alternative check:
Fabrication standards and handbooks specify hole oversize; inspection gauges and reamers are chosen accordingly. Empirical practice aligns with using larger holes to avoid damage during driving and to ensure full seating of the rivet head and shank.

Why Other Options Are Wrong:

• Equal or smaller holes hinder insertion and risk plate damage or misalignment.
• “Depends only on thickness or material” ignores the primary fit and tolerance requirement; while these affect allowance magnitude, the direction is always “greater than”.

Common Pitfalls:
Using rivet diameter instead of hole diameter in calculations; neglecting clearance leading to practical assembly issues and residual stresses.

Final Answer:
greater than