Another illustration of the malleability of metal is afforded by metal spinning.
Substances having high specific gravity, malleability, opacity, and especially a peculiar lustre, the term "metal" became generic for all substances with these properties.
Iron renders the metal hard and brittle; arsenic, antimony and bismuth (up to 0.5%) reduce its tenacity; copper and lead (1 to 2%) make it harder and stronger but impair its malleability; and stannous oxide reduces its tenacity.
The malleability and ductility of metals lie at the basis of the work of the goldand silver-smiths at one extreme, and of the boiler-maker at the other.
Experiments he made with South Wales iron were failures because the product was devoid of malleability; Mr GOransson, a Swedish ironmaster, using the purer charcoal pig iron of that country, was the first to make good steel by the process, and even he was successful only after many attempts.
This term of course includes as special cases the qualities of "malleability" (capability of being flattened out under the hammer) and "ductility" (capability of being drawn into wire); but these two special qualities do not always go parallel to each other, for this reason amongst others - that ductility in a higher degree than malleability is determined by the tenacity of a metal.
The abundance in which iron is found in so many places, its great strength, its remarkable ductility and malleability in a red-hot state, and the ease with which two heated surfaces of iron can be welded together under the hammer combine to make it specially suitable for works on a large scale where strength with lightness are required - things such as screens, window-grills, ornamental hinges and the like.
Austenite may contain carbon in any proportion up to about 2.2 It is non-magnetic, and, when preserved in the cold either by quenching or by the presence of manganese, nickel, &c., it has a very remarkable combination of great malleability with very marked hardness, though it is less hard than common carbon steel is when hardened, and probably less hard than martensite.