What is a Ferrule? Definition, Uses, and Applications

A ferrule is a small metal or plastic pin or tube that is used to hold two or more parts together, typically in a mechanical assembly. It is often used as a pivot or hinge point to allow movement between the parts while maintaining their connection.

Ferrules are commonly used in a wide range of applications, including:

1. Precision instruments: Ferrules are often used in precision instruments such as telescopes and microscopes to hold lenses or mirrors in place.
2. Mechanical assemblies: Ferrules can be found in mechanical assemblies such as gears, bearings, and other moving parts.
3. Aerospace applications: Ferrules are used in aerospace applications such as aircraft landing gear and control surfaces.
4. Medical devices: Ferrules are used in medical devices such as surgical instruments and prosthetic limbs.
5. Optical fibers: Ferrules are used to hold optical fibers in place in fiber optic connectors.

The term "ferrule" is derived from the Old French word "ferruler," which means "to rule with iron." It was originally used to describe a small metal rule or measuring tool, but has since been applied to other uses where a small metal pin or tube is used to hold parts together.