The market for stainless steel investment casting is growing, driven by opportunities in aerospace, defense, energy, medical, and food and beverage. Foundries are investing in automation and 3D printing technologies as they seek a competitive advantage through shorter lead times and improved quality. Three AFS member companies recently shared how their operations are evolving and what they see for the future of their stainless-steel casting operations.

Investment casting, also known as lost-wax casting, is a precision metal casting process that involves creating a ceramic mold around a wax pattern, melting out the wax, and then pouring molten metal into the resulting cavity. After casting, the ceramic mold is destroyed to remove the part.

This process allows for the production of highly-accurate, intricate parts with excellent surface finishes. Parts are produced close to their final desired shape, which reduces material waste and machining time. Stainless steel offers the corrosion resistance needed for harsh environments. It can be welded, bent, and cut; is infinitely recyclable with no loss of quality; and requires minimal maintenance.

Robert Tuttle, associate professor at Western Michigan University and chair of the AFS Steel Committee, believes stainless steel investment castings have the most viable opportunity to capture market share from ductile iron components due to their higher strength and reduced need for machining.

At AFS Corporate Member Fisher Cast Steel Products, located in West Jefferson, Ohio, stainless steel investment castings have been part of their operations for more than 50 years. Recently, however, the company began focusing more heavily on investment casting and made significant capital investment in its operation.  

“It’s a growth area for us,” said Jay Harmeyer, president. He believes that higher volumes in investment casting present an opportunity to become more efficient and automated through robotics. “At least for Fisher, our stainless-steel investment-cast parts are typically less than 20 lbs., and the volumes are generally higher, so it allows you to fine-tune your processes.”

AFS member Stainless Foundry & Engineering, based in Milwaukee offers both sand casting and investment casting, and has seen business for the latter increase over the last five years.  

“We have seen a growing interest among customers to transition some products from sand casting to investment casting,” said Mat Staudinger, recently promoted to CEO. He also notes that onshoring activities are generating more revenue for the investment casting side of the business.

According to Staudinger, reasons for converting vary: Some clients may seek higher-quality parts, others want to reduce post-cast processing or find a more cost-effective long-term strategy. Investment casting appeals to customers producing parts with complex geometries, undercuts, internal passages, thin walls, and intricate features––challenges for other casting methods. Stainless steel currently represents approximately 70% of the company’s investment casting production.

AFS member Wisconsin Precision Casting, with locations in Lake Geneva and East Troy, focuses on short to medium runs of highly-engineered parts, about 40% of which are stainless steel. With several 3D printers, they can produce prototypes in 7–10 days, and 90% of their wax patterns are printed in-house.

According to General Manager and Co-owner Tony Ansorge, expansion into 3D printing six years ago has been a major boost.
“I feel like it’s put us out in front of everybody else. It just seems like no one’s jumping in––I don’t really know why, but they’re not.”

He’s cautiously optimistic about the stainless-steel castings market.

“We’re seeing new work, fresh drawings, and quite a few prototypes happening,” he said. Prototypes that are initially investment cast may eventually be sand cast, giving Ansorge a glimpse into the industry’s trajectory.

The Need for Speed

“The biggest trend that I’ve seen thus far is for faster delivery,” said Staudinger. “Customers want it faster––and it’s across the board: commercial, industrial, nuclear, and military clients.”

One way to cut lead times is by using 3D printing to make patterns for investment casting. According to Tuttle, investment casting foundries have led the way in adopting the technology.

“3D printing significantly reduces production time compared to traditional methods, especially for prototypes and small production runs,” said Ansorge.

Instead of taking several weeks to design, manufacture, and validate tooling, 3D printing can often complete the task in days or even hours. For short runs, 3D printed patterns are also much more economical than traditional dies. Stainless Foundry, Fisher Cast Steel Products, and Wisconsin Precision Casting are all using the technology.

There are cost advantages as well, with 3D printing providing 50%–90% cost savings on complex prototypes. Despite the advantages, conventional patterns still dominate. According to the Mordor Intelligence Report, those still represented about 87.27% of revenues in 2024.

Direct-shell printing––such as Printed Investment Shell Casting (PICS) technology, which bypasses wax entirely––is not yet used by any of the foundries interviewed. 

“We don’t feel that the technology is at a point that makes sense to get in,” said Ansorge. While PICS offers significant advantages for specific applications, it is not yet the industry standard.

Beyond 3D printing, Stainless Foundry recently launched a stocking program that cuts customer wait times from 6–8 weeks down to just one or two.

“It’s allowing us to be a lot more serviceable to our customers and removes the intensity of the expedites,” said Staudinger. “It also gives us flexibility to build a schedule that fits us.”

The Repeatability Challenge 

Repeatability remains a major challenge for stainless steel investment casting foundries. “You want to make sure that your process is the same every time,” Ansorge underscored.

The investment casting process involves many variables that can affect the final product––from the viscosities of liquid slurries and ceramic dipping routines to preheating methods and metal pouring temperatures––even the air temperature. 

“It’s really critical to us to keep all the HVAC systems working right,” said Ansorage. “It keeps everything a lot healthier on the front end of our process. There are a lot of things we have to keep tabs on and control. That’s the biggest challenge of all.”
Staudinger agreed: “We want to control all of our inputs and outputs to such a level that will give us a repeatable product. These end customers are depending on us to generate reliable and dependable parts.”

Success with Simulation 

Before casting even begins, foundries use simulation software to improve first-time success rates.

Stainless Foundry & Engineering and Fisher Cast Products utilize SOLIDWORKS 3D CAD solid modeling software and MAGMASOFT solidification software to create custom designs, develop gating and rigging solutions, and predict casting soundness. Similarly, Wisconsin Precision uses NovaFlow&Solid modeling software. 

The digital tool on the horizon for investment foundries are digital twins––virtual dynamic replicas of the casting process that encompass the physical components, machinery, and even the entire foundry environment. A key advantage is they can provide real-time data and feedback during the casting process to enhance quality and consistency.

Automation Enhances Efficiency

Automation is removing many of the variables in investment casting while reducing dependence on skilled labor.
At both Wisconsin Precision Casting locations, the shell-building process is nearly all robotic.

“It reduced my head count requirements by eight people,” said Ansorge. “It provides cost savings but also relieves HR from having to fill eight more positions.”

With precision control of the dipping process, robots ensure consistent shell thickness, which is important for preventing defects like cracking or warping. This also means less material is used. A consistent coating results in 15%–20% savings in shell materials. Because they can operate 24/7, overall production can be increased, and with fewer workers involved in shell building, the risk of injury from repetitive and physically demanding tasks is reduced. 

Fisher Cast Steel Products plans to install a robotic dipping machine later this year. Stainless Foundry & Engineering currently has three robots dedicated to shell-making.

Automated grinding is another area showing great returns.

Fisher installed automated grinding several years ago and praises the consistency it delivers.

“It may not be faster than a skilled person,” said Harmeyer, “but it’s consistent, it’s safe, and anyone can run it.”

Wisconsin Precision Casting also uses automated grinding and is considering upgrading to more advanced equipment. Newer models typically include real-time monitoring and smarter controls. However, those advances come with a hefty price tag.  
“We’re doing everything we can, but it’s hard to afford,” said Ansorge. 

Even shell removal is becoming automated. In 2024, Stainless Foundry & Engineering installed a high-pressure water blast system that replaced manual methods like knockout hammers, salt baths, and hand chiseling.

The waterblast cabinet contains the entire process of removing the investment casting shells, using several gallons of water per minute at a powerful 20,000 psi. The new system greatly reduced the number of parts requiring soaking in the Kolene solution, greatly decreasing the probability of quality issues. Labor and inspection hours were reduced as were noise levels within the work area.  

Investing in People

Technology advances alone aren’t enough to meet the demand for faster and higher quality stainless-steel castings––workforce investment is just as critical for the industry. 

“Invest in your people,” said Staudinger at Stainless.  “If you’ve got a good team behind you, the best thing you can do is fully support them. You want to make sure that they continue to break through.” 

Stainless Foundry & Engineering is training employees on Programmable Logic Controllers (PLCs) to automate various processes within the foundry, enhancing efficiency, precision, and safety. “We’re taking manual processes and automating them,” Staudiner added. “We want employees to evolve, learn, and have the tools they need.”

Wisconsin Precision also benefits from a knowledgeable team that truly understands the technology.

“One of our engineers has printed parts for the 3D printers to make them work better,” said Ansorge. “He spends a lot of time tweaking that process and even makes recommendations to the manufacturer.”

The Future of Investment Casting

While there’s optimism about the future of stainless-steel investment castings, foundries will require significant investments in technology and people to remain competitive. 

Ansorge would like to see more government programs to help foundries invest in technology to become more competitive. “We don’t need tariffs,” he said. “To make us competitive with China’s low labor costs, tariffs would have to be 400%.”

Staudinger remains optimistic: “I’m very excited about our growth trajectory. We have the capacity, the knowledge, the personnel––and we’re doing all the right things.”

Harmeyer takes a more pragmatic approach, choosing to stay focused on aspects of the business he can control. 

“We just run a business and try to do the best we can. The market goes up and down, but if you focus on being the best version of yourself with continuous improvement, you’ll be successful. I want to continue to look for lean ways of doing things.