Malleability

(mal-le-a-bil'e-te.] [From L. malleus, a hammer.] (Phys.) The property of extending under the blow of a hammer. It is opposed to brittlene , and is almost restricted to metals. Malleable substances must be tenacious, resisting fracture, and soft, permitting the particles to glide over one another. The M. of the most common metals is in the following order: 1 gold, 2 silver, 3 copper, 4 platinum, 5 iron, 6 aluminium, 7 tin, 8 zinc, 9 lead. Gold may be reduced to leaves of 1-180,000th of an inch in thickne , and weighing only 3 grains per sq. foot. Leaf iron has been obtained 1-4800th of an inch in thickne , and weighing one -third of a grain per. sq. inch. M. is much influenced by temperature, the temperature of greatest M. being different for different metals. Iron is most malleable at a low white heat; in this state, therefore, it is welded or rolled into bars or plates. [s. 571]