Tin foil hat radio with a metal bucket. The AM radio is completely inside a metal enclosure. This leads to a noticeable reduction in signal strength received by the AM radio. The efficiency of a metal enclosure in blocking electromagnetic radiation depends on the thickness of the foil, as dictated by the "skin depth" of the conductor for a particular wave frequency range of the radiation. For half-millimetre-thick aluminum foil, radiation above about 20 kHz (i.e., including both AM and FM bands) would be partially blocked, although aluminum foil is not sold in this thickness, so numerous layers of foil would be required
Tin Woodman iron or steel but coated with tin (in order to prevent rusting) is called a "Tin" object, as a "tin bath", a "tin toy", or a "tin can"; thus, the Tin Woodman might be interpreted (in English, at least) as being made of steel with a tin veneer. One passage in "The Road to Oz," by Baum himself, wherein the Woodman attends Ozma's birthday party accompanied by a Winkie band playing a song called "There's No Plate Like Tin," strongly implies that this is the case. Another explanation may be that the Woodman is "chiefly" made of tin, with iron