| Abstrakt: |
Malleable-iron castings, according to the author, are regularly made weighing as high as 500 lb., with an ultimate strength of 50,000 lb. per sq. in. and an elongation of 10 per cent or over. With these properties in mind he compares such castings with gray-iron and steel castings, showing that with respect to the former the malleable casting has equal physical properties, costs no more, is lighter in weight and is not liable to breakage. More than 70 per cent of the steel castings produced in this country, it is stated, are not annealed and are in a state of internal strain. Annealed malleable castings are free from such strain, are less expensive to produce, and in the author’s opinion will stand more abuse in service. Their use is therefore indicated and recommended for any part of such size as can be successfully made where strength combined with ductility and low cost per pound is essential. |
