A pleated or flexible elastomeric sleeve installed over mechanical joints, sliding shafts, or electrical switches. It acts as a dynamic seal, retaining lubricating grease inside the mechanism while blocking the ingress of water, dirt, and abrasive particles. The accordion-like folds allow the component to stretch, compress, and articulate without exposing the sensitive internal parts to the environment.
The CV joint failed because the rubber boot tore and let sand mix with the grease.
When inspecting machinery, always look for grease splattered around a boot; it is the first sign of a tear before the joint actually fails.
Also heard as
- bellows
- dust boot
Related terms
Same word, different worlds
Field-built geomembrane sleeve that seals a liner around a pipe or other penetration.
Sealants & WaterproofingA preformed or field-built collar that seals a pipe, rod or conduit where it passes through a membrane.
Shop Floor SlangA brand new, highly inexperienced worker who has just finished basic training or school.