Ferrule (noun)

1. A metal or plastic ring or cap fitted around a slender shaft to strengthen it or prevent splitting.
2. A small metal band that fits over the end of a cane, a fishing rod, or a similar item to reinforce it.

Origin:

Mid 17th century: from french ferrele, from latin ferula "rod, cane".

Examples:

1. The ferrule on the end of the hiking pole prevents it from splitting.
2. The ferrules on the metal rod are worn and need to be replaced.
3. The metal ferrule on the end of the umbrella provides a sturdy tip.
4. A ferrule is used to join two sections of a fishing rod.
5. A metal ferrule was placed around the edge of the canvas to protect it.