What role do cotter pins play in mechanical assemblies?

Cotter pins are essential in mechanical assemblies as they serve to secure fittings and prevent disengagement of components. Their design allows them to be inserted through holes in two components, creating a reliable connection. Once the pin is inserted, the split ends can be bent back, effectively locking the pin in place and ensuring that the connected parts remain together, even under dynamic loads or vibrations.

This securing function is critical in various applications, from simple machinery to complex mechanical structures. The use of cotter pins is particularly advantageous in scenarios where it may be necessary to disassemble the components for maintenance or adjustments, as cotter pins can be easily removed and reused without damaging the parts they secure.

In contrast, the other options focus on different functions that do not align with the primary use of cotter pins. For example, cotter pins are not typically used for joining threaded components, preventing lateral movement in shafts, or providing electrical conductivity, which are functions handled by other specialized hardware or design features.