Evaluating six sprue designs used in making high-palladium alloy castings.

Six different sprue designs were studied to determine which, if any, could be used to produce more complete castings with a high-palladium alloy. A standardized mesh test pattern was used to ensure objective measurements and accurate evaluations of the spruing techniques. This study of problems usually encountered when casting high-palladium alloys found that: Differing sprue designs effect significant differences in obtaining complete castings (p less than .05) as indicated in the ANOVA. The connection between the casting and the sprue should be constricted to improve castability of high-palladium alloys. Although this spruing technique may be used in different sprue designs to improve the quality of castings, further research seems indicated.