Canadian foundryman (1921) . the writers opinion, should and will in timebe restricted to the production of that sizeof casting that cannot successfully be pro-duced in malleable iron and is too costly toproduce in steel, while it is peculiarly wellfitted for such castings as are designed tosustain static compression, for which pur-pose the gray-iron casting is without ques-tion superior to either of the other average ultimate tensile strength of thegray-iron casting as measured by the testbar does not exceed 20,000 lb. per sq. in.,while it possesses practically no writer
Canadian foundryman (1921) . the writers opinion, should and will in timebe restricted to the production of that sizeof casting that cannot successfully be pro-duced in malleable iron and is too costly toproduce in steel, while it is peculiarly wellfitted for such castings as are designed tosustain static compression, for which pur-pose the gray-iron casting is without ques-tion superior to either of the other average ultimate tensile strength of thegray-iron casting as measured by the testbar does not exceed 20,000 lb. per sq. in.,while it possesses practically no writer can state with positiveness thatin the case of at least sixty of the malleable-iron foundries the average ultimate strengthand elongation of their product, as measuredby the standard test bar, are 51,000 lb. per cent, respectively. 4. It can safely be stated that if a gray-ironand a malleable-iron casting are designed toperform the same function, the design ofeach being based strictly upon its physical. TWO ILLUSTRATIONS OF THE SAME MALLEABLE IRON CASTING BEFORE AND AFTERCOLD BENDING UNDER THE HAMMER. properties, in view of the great difference intheir relative strengths, coupled with thefact that a larger safety factor must be usedin the case of the former due to its inherentbrittleness, the latter can safely be mademore than one-third lighter. Inasmuch asthis difference in weight will in large measurecounterbalance the difference in cost perpound with the substitution of a ductilecasting for one that is brittle and is actuallymore easy to machine, the writer believesthat when this fact is fully understood andits significance appreciated, many castingsnow made of gray iron will be replaced bymalleable, with the result that the gray-ironcasting field will of necessity be narrowedto this extent. It is therefore logical toconclude, as between these two products,that if the part can be successfully cast ofmalleable iron, the following statementshold true: a For equal phy
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfoundri, bookyear1921
