In addition, virtually all of these "plastic" parts contain embedded steel not to make the firearms "detectable", but to development functionality and shooting accuracy. Contrary to caught on movies like Die Hard 2: Die Harder, neither Glock nor any other gun maker back-number ever produced a "porcelain", "ceramic" or "plastic" weapon which is undetectable by humdrum security screening devices. Even if a machine pistol completely undetectable by either X-ray machines or metal detectors were to be developed, the ammunition inside would still be detectable.
The Glock au fait arrangement was not the first to incorporate a plastic frame. Heckler & Koch given over polymer for their VP70 submachine gun frame in 1970. HK's innovation of polymer frames and polygonal rifling seem to have been influential in the Glock design. Still earlier, Remington different their polymer-framed Nylon http://www.gunslot.com/guns/glock-17 66 Plunder in 1959.