Pewter, an alloy of tin with other metals, such as lead, bismuth, antimony, copper, and zinc, in varying proportions. The English pewterers recognize three kinds, called plate, trifle, and ley pewter; the first and hardest being used for plates and other household articles, the second for beer pots, and the third for larger wine measures. Plate pewter is composed of 100 parts of tin, 8 of antimony, 2 of bismuth, and 2 of copper, and has a bright silvery lustre. Trifle contains 83 parts of tin and 17 of antimony, with usually considerable lead. Ley contains 4 parts of tin and 1 of lead, and is generally known as common pewter. Another formula is, tin 112, lead 16, copper 6, zinc 2. A kind of hard pewter is composed of tin 96, antimony 8, copper 2. Some think the best pewter is made of tin 100, antimony 17; others that the finest is made by adding " temper" (which is composed of 2 parts of tin and 1 of copper) to tin in the proportion of from 0.08 to 1 per cent., or one third that proportion of copper. Britannia metal, consisting of tin 86, antimony 10, zinc 3, copper 1, and Queen's metal, containing tin 9, antimony 1, bismuth 1, lead 1, are kinds of pewter used for domestic utensils. Some inferior kinds of pewter contain 50 per cent, of lead, by which poisonous properties are imparted.
To obviate the difficulty, the French government appointed a commission, who determined that no more than 18 parts of lead might be safely alloyed with 82 parts of tin, and a standard was adopted of 83.5 tin and 16.5 lead in 100 parts, allowing 1.5 per cent, for unintentional errors. The density of this legal standard is 7.764; any increase of lead increases the specific gravity. Pewter vessels are formed by hammering, or by casting in moulds. When cast in pieces they may be joined together with soft solder. (See Solder).