Riveted assembly

Rivets provide a simple and economic assembly, and produce a strong permanent mechanical joint. They are used to join thin sections of plastics, plastic to metal sheet or plastics to fabric. The process can easily be automated. Different types of rivet heads are available.

The diameter of the head must preferably be three times the shank diameter to reduce the stresses in the parts by distributing the clamp force over a larger area. A conical head should not be used, as it produces high tensile stresses.

Rivets can be produced from metal or plastic. Aluminum and plastic rivets produce smaller compressive stresses in the parts.

A clearance between the rivet and the molded hole of 0.25 mm (0.010 inch) is recommended to account for tolerance variations and the coefficient of thermal expansion mismatch. A head is formed at the shank by plastic deformation of the material. The head can be made with a hand vice or a press. The figure below shows a typical example of a heading tool. Load control devices should preferably be used during rivet installation to ensure correct clinching pressure and consistent assembly thickness.

Heading tool

A reinforcing washer under the head of the rivet helps to minimize the stresses in the parts, just like a shouldered rivet.

Shouldered rivet