Can an invention be considered patentable if every individual component within it is a common or well-known element?

Yes, it is the particular combination of components/elements that is relevant in this analysis.  For example, Patent #5,502,918 to Oviatt claims a mousetrap using wire, a plastic tube, and a ping-pong ball to trap a mouse. Although each individual material used is a common, well-known element (wire, plastic, a ping-pong ball), combining these elements in the particular way that Oviatt has described to form a mousetrap yielded a novel, non-obvious and ultimately patented invention.