Crack in neck of hollow shaft is a very serious malfunction, main cause of the crack include: foundry defect, centralized stress, quality problems of welding and heat treatment.

The main task of this paper is to develop prediction & analysis system of shrinkage cavity and porosity defect in a casting for foundry engineering application.

It has been found out that the defect was caused by adopting the foundry method with a cold riser which actually acted as a cold metal bleeder.