The applications of powder metals have long been thought to rapidly increase due to low total production costs, but difficulties to guarantee mechanical or dimensional properties have slowed the growth down. To overcome these obstacles, the quality of the powder metallurgical process must be improved. Quality improvements of any process requires work, and the powder metallurgical processes are no different. Factual evidence makes the work much more efficient, and statistical methods are developed to provide facts of the object under study. Here, statistical methods as well as metallurgical investigations are used to find potentials for improving sinter steel products. The work has studied the iron phosphorous system, as well as water atomization of iron powder.