The translation of laboratory results in simple test plate tastings to the production of a fairly large, high quality casting has been described. By judicious chilling of the casting, and by careful foundry practice, the mechanical properties of the casting were raised substantially above present design minimums. Properties of coupons cut from the sand casting of 195 alloy made without chills averaged 36,900 psi ultimate tensile strength, 25,200 psi yield strength, and 4.3 per cent elongation. Addition of chills raised these average properties to 46,900 psi ultimate tensile strength, 28,400 psi yield strength, antl 10 per cent elongation. Chilling raised the average properties of the same casting made in 356 alloy from 31,000 psi ultimate tensile strength, 26,400 psi yield strength, and 1.4 per cent elongation to 42,300 psi tensile strength, 32,700 psi yield strength, and 5.8 per cent elongation. The properties of the chilled 195 alloy casting represent an improvement over present minimum specifications of 95 per cent in ultimate tensile strength, 42 per cent in yield strength, and thirteen hundred per cent in elongation. The properties of the chilled 356 alloy casting represent a similar improvement of 89 per cent in ultimate tensile strength, 63 per cent in yield strength and 800 per cent in elongation.
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