BOA metal bellows are produced from ductile metallic materials. The basic element, which is a thin-walled cylindrical tube, is formed into corrugations using hydraulic or mechanical pressure. Different procedures and corrugation geometry are adopted depending on the production quantity and application.
 
Made of single or multi-ply elements, BOA metal bellows are:
- extremely flexible,
- offer considerable axial, lateral or angular movements,
- have a long life expectancy,
- do not need any maintenance,
- are resistant to pressure and to temperature,
- are vacuum-tight