Investment Casting Parallelism

Casting parts with parallel prongs supported at only one end, and yoke castings, are very specialized problems which should be discussed fully with the foundry before production.

Since Point X is the thickest section, it is the ideal gate point. It is also where the greatest volumetric shrinkage will occur.

Dimension Y, however, will be restrained by the rigid mass of refractory. Parallelism is therefore difficult to maintain. It will be .010" per 1" of L, but can be improved by control techniques and sizing. This condition will also affect any through holes usually found in yokes. When specified, such holes should carry considerable finish stock if they are to be finished truly concentric or line reamed.