Usual techniques used in the automatic test case generation and executions assume that a complete oracle will be available during the testing process. However, in some numerical programs this assumption is not valid because the oracle in form of analytical solution is either not available or too difficult to obtain. To overcome this problem, metamorphic testing proposes to generate follow-up test cases to check important properties of the output function. We study the intrinsic properties of Medial Axes for casting applications. Even though Medial Axes is a geometric function that is independent from the output function of casting simulation, we propose to use its intrinsic properties for metamorphic testing of casting simulation to alleviate the oracle problem.