Spruing: Rules for Sprue Attachment and Review of Different Types of Sprues

The importance of the attachment of sprues to wax patterns should not be underestimated. The spruing system as well as shape and position of the sprues in the casting ring have a significant impact on the accuracy of fit, porosity and stresses in the eventual cast object. The sprue system has to gurantee that the flow of liquified alloy into the pattern chamber is unimpeded. The sprue system must be in keeping with the operating principle of casting equipment. Obstacles and significant diversions in the molten flow can result in thin areas of marginal parts not being completely filled.