What is the term used for a pin that secures two or more parts by positioning through holes in them?

The term used for a pin that secures two or more parts by passing through holes in them is indeed a cotter pin. Cotter pins are designed to hold machine components, such as rods and shafts, in place within their assembly. They are typically inserted into a pre-drilled hole and then bent at one end to prevent them from slipping out, providing a reliable means of securing components while allowing for ease of disassembly when necessary.

In contrast, fasteners is a broader term encompassing a variety of hardware devices used to join or secure objects together. This includes screws, bolts, and nuts, which serve different purposes than a cotter pin.

A clevis, while it can secure parts, is specifically a U-shaped object that often requires a pin or a bolt to hold another component, and it does not function as a standalone pin itself.

A rivet is another fastening method that permanently joins materials together, typically involving the deformation of the rivet after it has been inserted, making it unsuitable for applications needing disassembly like those served by a cotter pin.

Thus, a cotter pin is the most accurate term for a pin that directly secures two or more parts by being positioned through holes in them.