Bellows are thin-walled, flexible structural components defined by their repeating corrugated or folded geometries—distinct from smooth-walled pipes—designed to accommodate axial, lateral, or angular movement while maintaining leak-proof seals. These elements play a critical role across industries, bridging gaps between rigid systems and dynamic operating environments, and their versatility stems from tailored material selection and precision manufacturing.

The core design of bellows features evenly spaced, curved ridges (corrugations) that enable elasticity: stretching, compressing, or bending without permanent deformation. Materials vary by application: metal bellows (most common) use stainless steel, copper alloys, or titanium, prized for high strength, temperature resistance, and durability. Non-metal bellows rely on polymers like PTFE (Teflon) for corrosion resistance to acids and bases, or silicone/PVC for biocompatibility in medical settings.