Importance of Parting Line in Die Casting

Die cast engineers and designers consider a number of factors while deciding on the elements that are involved in the process of metal die cast design. One of the very important elements involved in the process is the geometry of the cast part and its relation to the placement of the parting lines.

Parting Lines

Die cast engineers will know that the dies must be made in a minimum of two parts. When this die is placed inside the cast machine, these two parts of the die will come together to make the halves of the finished product. This is applicable for Magnesium, Aluminum, Zinc, or any other alloy that is used in die casting.

You will be able to note a visible line around the perimeter of the finished product. This line runs exactly where the two portions of the die meet together. This line is usually referred to as the parting line, and it is the parting line that defines which half will act as the “cover” die and which one will act as the “ejector” die. This also determines how the rest of part will be designed.

Importance of Parting Line

The parting line decides the overall design of the die cast part in relation to the following considerations.

Cost Efficiency

  • Proper positioning of the parting line is important for the reduction of flash formation
  • Reduce or eliminate the need for hand filing, trimming, or additional flash removal
  • It decreases the need for machining

Cosmetic Appearance

  • It is important to design and place the parting line to flow with the corners and contours of the design. This will help optimize the overall aesthetics of die cast parts.

Engineering Requirements

  • Parting lines influences tolerances that are to be held in the casting area
  • It influences wall thickness, draft angles, and other geometric considerations
  • It influences the flow of metal and integrity of the casting

Usually, the die caster takes the final decision on the placement of the parting line while working on the die cast design. However, is very important to discuss the placement of the parting line and the various option that are available before deciding on the final design.