What is a spanner nut?

A spanner nut is a type of fastener that has a specific design allowing it to be tightened or loosened using a spanner, or wrench. It typically features a unique shape, such as holes or notches, which require a corresponding tool for manipulation. Spanner nuts are commonly used in applications where secure fastening is critical, such as in machinery or automotive components, to prevent unauthorized access or accidental loosening.