Investment Casting Gate and Runner Design

The investment casting process consists of several critical steps that must be engineered and carefully followed in order to produce compliant and repeatable parts. One of the most important steps in this process is designing and validating the gate and runner system. There are many key considerations when designing these systems, and if done incorrectly the mold will not function properly. Additionally, an incorrectly engineered gate and runner system can lead to cosmetic defects, reduced material properties, porosity and high scrap amongst other things. At American Casting Company our engineering team is extremely knowledgeable at designing the gates and runners for the investment casting process, and we validate them by using Pro-Cast solidification analysis software.

Investment Casting Gate and Runner Design at American Casting Company

Before starting the discussion on our capabilities in the gate and runner design arena, it is essential to understand the two terms of “Runner” and “Gate”.

  • Runner: The runner system is what the metal flows through after entering the pour cup as it travels toward the in-gates on the parts. Runners are either hand built using wax sticks or can be injected into custom shapes depending on what is required. The runner system also provides feed metal to the parts as the castings solidify. If properly designed, the runner system ensures that the mold fills in a balanced and non-turbulent fashion.
  • Gate: A gate is simply an opening between the runner and part cavity that ushers the molten metal into the cavity and feeds the casting as it solidifies. A part cavity can have more than one gate if needed. The location, type, and size of the gate influences the finished parts which is why we pay special attention when sizing and designing these systems.

With years of experience in designing gate and runner systems for the investment casting process, we know the importance of ensuring this is done correctly. Here is a list of the key items that are considered when gate and runner design is performed:

  • Gates should be placed on the heaviest or thickest sections of the part.
  • Ensure all isolated heavy sections have gates or feed paths.
  • Ensure gates are located where parts can be de-waxed without trapping wax in isolated cavities.
  • Locate the gate in a non-critical location of the part if possible.
  • Ensure the gate is located in an area that can be easily cut-off and ground to size.
  • Place gates away from cores if possible to minimize obstructions and pressure in the flow path.
  • Round parts, such as gears should be gated centrally, whereas cup-shaped parts should be gated near the base or flange.
  • Ensure size of gate is proportional to area gate contacts and will be feeding.
  • Ensure gate locations will not cause un-intended bending or distortion to the finished part.

Markets Served

Our expertise and experience with gate and runner design enable’s us the ability to produce a wide variety of parts and shapes that meet our customers specifications. This help us gain a competitive advantage in the following markets:

  • Aerospace
  • Defense
  • Medical
  • Electronics
  • Automotive
  • Oil and Gas
  • Agriculture
  • Commercial

Certificates and Compliances

Being an ISO 9001 and AS9100 certified organization, we consider quality seriously. The parts are produced in compliance with the following certifications:

  • NADCAP for special processes


  • ITAR (International Traffic In Arms Regulations)
  • EAR (Export Administration Regulations)

If you need more information on Investment Casting Gate and Runner Design, please contact us at your earliest convenience.
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