Glass, rubber, titanium alloys, aluminium alloys (2024-T3 & 6061-T6 very much used), copper, glass-reinforced plastics, carbon-fibre composites, acrylonitrile plastics, steel, hastelloy, synthetic fibres, some ceramic components, natural fibres, polytetrafluoro-ethylene and derivatives, some gold, some silver, some other stuff (silicon, ruby, etc) as well, depending on the manufacturer, equipment fit, customer options etc etc. This list is far from exhaustive. Some aircraft have genuine wood in them as well.