Die Materials

The cost of the tool is a major factor in the economics of die casting. The machined tool steel die is a significant investment that ideally will last for the entire production life.

The two most common causes of tool damage are molten metal erosion and surface cracking (heat checking) from overheating.

With cumulative damage over time, dimensional tolerances and surface finish limits are exceeded. When that occurs, the tool must be repaired or replaced.

The large size and mass of the heat sink block produces a high heat load on the tool surface. In initial production runs, the Premium Grade H13 tool steel showed excessive wear and surface damage.

Close Up View of Ejector Half Tool

The engineers at St. Clair Die Casting shifted to a proprietary tool steel alloy which had higher strength, better thermal conductivity, and improved thermal fatigue life, compared to Premium Grade H13 tool steel. With the new tool steel alloy, the die life was markedly extended with major cost savings and improved yield over the production run.