Urethane cast parts are perfect for low-quantity production—when volumes do not justify investment in injection mold tooling—as well as for first run production parts. This process is a quick, cost-effective way to produce 10-200 units with production-level quality.

The urethane casting process and relatively inexpensive tooling involved makes it easy and economical to make any necessary design changes. Additionally, different materials can be used with the same mold, making it possible to test designs with a variety of materials.

Urethane casting allows for almost limitless complexity, including sharp internal corners unachievable with CNC machining, and designs without draft or uniform wall-thickness that can’t be injection molded.

End-user functionality and a high-quality finish makes urethane cast parts ideal for consumer testing, user evaluation and concept models. Using the cast urethane process means that changes can be incorporated quickly for either further testing or market launch.

About the Urethane Color Options

Polyurethanes can be blended with pigments to achieve a variety of colors. Naturally, a urethane may be amber to milky-white in color. Xometry's clear urethane options are formulated to be colorless. Below are Xometry's color options:

About the Urethane Casting Process

Urethane casting (also known as RTV molding, cast urethane, and silicone molding) is a fabrication method that uses silicone molds to produce production-quality plastic parts.

Urethane Casting production consists of three main steps:

‍1. Build a master pattern using 3D printing or CNC machining
2. Build the mold by pouring platinum silicone around master
3. Pour liquid polyurethane resin into mold, create polyurethane casting under vacuum

Advantages of Urethane Casting

With urethane casting, you can get production quality parts at low volumes and without the high costs and lead times of steel or aluminum tooling. This is helpful for bringing new products to market where you may want production-grade products to test with new customers and markets and validate your design hypotheses before making a substantial investment to scale manufacturing.

Urethane Casting Design Considerations

If you are familiar with designing parts for injection molding, you can apply the same best practices and rules of thumb to design parts for urethane casting.