Rivets, made of strong materials such as steel and aluminum, hold pieces together when assembling objects. Because the parts held by a rivet can pull apart from each other with considerable force, it is important to know how much load a rivet can take before the stress forces break the metal. In particular, the shear strength of a rivet measures the amount of force that can be applied transversally (i.e., perpendicular to the main axis of the rivet) before the rivet gets torn in half. You can compute the shear strength of the rivets you use in your projects.
Determine the area of the cross section of the rivet, either from manufacturer's specifications or by cutting a rivet apart transversally. If the rivet is solid, compute the area using this formula: A = Pi x (D / 2)^2 . Replace D by the diameter of the rivet, measured using the calipers.
If the rivet is hollow, compute the area using this formula: A = Pi x ((D / 2)^2 - ((D - t)/2)^2). Replace D by the (outer) diameter of the rivet, and t by the thickness of the rivet's wall, measured using the calipers.
Find out the shear strength of the metal the rivet is made of, by looking it up on Table 2 on "Mechanical Properties of Metals" table.
Calculate the shear strength of your rivets by evaluating this formula: F = A x S. Replace S by the shear strength of the metal found in Step 2. Your rivets can tolerate shear forces of up to F Newtons before breaking apart.