Investment Castings - Franklin Precision Castings

Precision. Quality. Reliability.

The Franklin team began investment casting production in 1985 and has since grown into one of the leading automated investment casting foundries in the U.S. With our onsite tooling team, automated casting foundry, and CNC machine shop, we enable faster turnaround times without compromising quality.

The Investment Casting Process

Investment casting, also known as precision casting or lost-wax casting, is a versatile and intricate manufacturing process that transforms detailed designs into high-quality metal components. This method is recognized for its ability to produce complex custom designs with exceptional accuracy and surface finish.

Step 1: Engineering Review/Drawing

Casting engineers review the Design For Manufacturing (DFM) drawing to consider the feasibility of the project.

Step 2: Tooling

In this stage, tooling is designed and manufactured according to drawings that include production and specification requirements. Few castings houses have their own in-house tooling capabilities like Franklin – allowing for expedited casting deliveries and new product development.

Step 3: Pattern Creation

The process then involves the creation of a wax pattern that replicates the final product. This pattern is produced using a mold, often with multiple patterns attached to a central wax tree.

Step 4: Assembly (Tree Formation)

These wax patterns are then assembled onto a central wax sprue, creating a tree-like structure. This assembly is then coated with a ceramic shell through a series of dipping and coating processes.

Step 5: Shell Formation

The coated assembly is subjected to repeated cycles of dipping in ceramic slurry and coating with fine stucco material. This builds up a robust ceramic shell around the wax patterns, creating a mold.

Step 6: De-Waxing

Once the ceramic shell is set, the entire assembly undergoes a controlled heating process, causing the wax to melt and drain out. This is where the term “lost-wax casting” comes from.

Step 7: Firing

The ceramic mold is then fired to cure and harden the shell, preparing it for the molten metal.

Step 8: Metal Pouring

With the mold ready, molten metal (often alloys of steel, aluminum, bronze, or other metals) is poured into the mold, taking the shape of the wax pattern.

Step 9: Cooling and Breakout

The metal is allowed to cool and solidify within the ceramic shell. Once cooled, the ceramic shell is broken away, revealing the finished metal casting.

Step 10: Finishing

The castings undergo final finishing processes such as grinding, polishing, and machining to achieve the desired specifications and surface quality.

Step 1: Engineering Review/Drawing

Casting engineers review the Design For Manufacturing (DFM) drawing to consider the feasibility of the project.

Step 2: Tooling

Step 3: Pattern Creation

The process then involves the creation of a wax pattern that replicates the final product. This pattern is produced using a mold, often with multiple patterns attached to a central wax tree.

Step 4: Assembly (Tree Formation)

These wax patterns are then assembled onto a central wax sprue, creating a tree-like structure. This assembly is then coated with a ceramic shell through a series of dipping and coating processes.

Step 5: Shell Formation

The coated assembly is subjected to repeated cycles of dipping in ceramic slurry and coating with fine stucco material. This builds up a robust ceramic shell around the wax patterns, creating a mold.

Step 6: De-Waxing

Once the ceramic shell is set, the entire assembly undergoes a controlled heating process, causing the wax to melt and drain out. This is where the term “lost-wax casting” comes from.

Step 7: Firing

The ceramic mold is then fired to cure and harden the shell, preparing it for the molten metal.

Step 8: Metal Pouring

With the mold ready, molten metal (often alloys of steel, aluminum, bronze, or other metals) is poured into the mold, taking the shape of the wax pattern.

Step 9: Cooling and Breakout

The metal is allowed to cool and solidify within the ceramic shell. Once cooled, the ceramic shell is broken away, revealing the finished metal casting.

Step 10: Finishing

The castings undergo final finishing processes such as grinding, polishing, and machining to achieve the desired specifications and surface quality.

Advantages of Investment Casting

Superior surface finish and dimensional repeatability
Tight tolerances and zero to minimal draft angle
Fine detail reproduction
Produce to near net shape
Reduction/elimination of machining
Ability to cast complex geometries
Capable of casting thin wall castings
Range of alloys and casting sizes
Inexpensive wax tooling
Recyclable raw materials (ex. wax and ceramic shell molds)

Why Franklin for Investment Castings?

The Franklin team accepts every challenge head-on, working closely together to turn complexity into craftsmanship on a daily basis. With a can-do attitude permeating every corner of our foundry, we’re able to embrace even the most unique requests while delivering exceptional results – every time.

End-to-End Capability

Experience automated end-to-end investment casting solutions under one roof, at our U.S.-based facility in Franklin, PA.

Diverse Alloy Offering

We offer a broad spectrum of over 120 standard and custom stainless steel, brass, bronze, nickel, cobalt, and aluminum alloys. Our in-house metallurgical engineer can propose metals and treatments to minimize cost without compromising the function or performance of the component.

Accelerated Timelines

We know time is of the essence for your operation, which is why our onsite tooling and engineering teams work to ensure every request is completed on time and on budget.

Unrivaled Precision

Our investment castings are engineered using state-of-the-art automation and meticulous attention to detail, resulting in the highest standard of accuracy in every part.

Customer-Centric Approach

Your success is our success. Throughout our foundry, our team works seamlessly with you to provide a collaborative and transparent experience that aligns with your unique needs.

Alloys We Pour

We pour over 120 alloys in our U.S.-based facility, including standard and custom stainless steel, nickel, cobalt, brass, bronze, and Ni-Hard alloys to suit the requirements of complex cast subassemblies or assemblies.

Stainless Steels