How stamping and fabrication work together
South Carolina contract manufacturer takes a hybrid approach
At Fisher-Barton South Carolina, historically a stamping operation, now gets half of its revenue from products that use metal fabrication. But there's not a stamping and fabricating "side" to the business. In fact, the part flow shows just how complementary fabrication and stamping can be.
Consider a large Tier 1 supplier that mainly serves the automotive sector, but its fastest-growing business happens to be elsewhere. The stamper has one principal disadvantage, though. Much of this work requires volumes that, while not extremely small, are still too low to justify building a complicated stamping die. So some of these nonautomotive jobs go to area contract fabricators with established laser cutting, punching, press brake bending, and welding capabilities.
This could represent any number of large stamping facilities around the country, and a year and a half ago, it was Alex Robertson’s world. Robertson has years of experience in manufacturing sales in the Southeast. Until 2012 he worked at a stamper that had significant automotive business, but nonautomotive jobs had the greatest growth potential. Still, the company lost out on a lot of that work because volumes weren’t high enough to build a tool.
So when Robertson changed jobs in late 2012 to become business development manager at Fisher-Barton South Carolina (FBSC), he saw big potential. Unlike his previous employer, FBSC had the capabilities to serve industries outside the automotive business.
Located in Fountain Inn, south of Greenville, FBSC designs and builds stamping dies. It has fabrication equipment, including lasers (see Figure 1), a press brake, and welding robots. Moreover, the company has a unique austempering line for heat treating before or after welding.
By late 2013, about half of FBSC’s revenue came from products that use metal fabrication processes. But as sources explained, the company isn’t set up to have a fabrication or stamping “side” of the business. In fact, the floor layout and part flow show just how complementary fabrication and stamping can be.
Near the back of the South Carolina plant is a room with two massive vats that hold a series of high-temperature salt baths. One automated line uses a massive gripper; in it is a batch of stamped lawnmower blades that are about to become a lot harder and, at the same time, more resistant to fatigue. After undergoing a series of heating, quenching, and hold times, parts emerge with a bainite microstructure. The heat-treat process produces Marbain® lawnmower blades, which are made of a heat-treated boron alloy steel, AISI 10B38.
“Watch for it. Here it comes.”
Robertson pointed to a batch of blades being lifted from a high-temperature salt bath. The blades glowed red briefly before moving on to the next heat-treat stage (see Figure 2). Phase transformation, here we come. This process traces its roots to Fisher-Barton’s beginnings, when, not surprisingly, a metallurgist played a primary role.
Dick Wilkey learned metallurgy at the University of Wisconsin-Madison. After graduating he worked in the steel industry, eventually landing a job selling lawnmower blade material to a Wisconsin stamper that eventually closed its doors. Wilkey ended up purchasing the stamper’s assets and, working with his connections in the lawnmower blade arena, launched Fisher-Barton in 1973.
Then as now, lawnmower blades present a special manufacturing challenge. Say you run your blade over a metal spike. Industry-accepted safety standards say the blade should not shatter. That means it can’t be brittle, and it needs to have high fatigue strength. But how do you make blades that stay sharp and last a long time? Traditionally, if the material becomes harder, it also becomes brittle.
After several years of testing and development, Wilkey and his team came up with an answer: Marbain, a proprietary material that’s both hard and fatigue-resistant, made with the company’s unique austempering heat-treat process.
These early successes led to expansions and acquisitions that ultimately created a company with an unusual process portfolio. The Fisher-Barton Group serves as the umbrella over eight subsidiaries, with plants across the country and overseas. Accurate Specialties Inc. in Waukesha, Wis., makes bronze gear blanks. Fisher-Barton Specialty Products in Watertown, Wis., makes wear-resistant agricultural and construction components. Zenith Cutter in Loves Park, Ill., and Ho Chi Minh City, Vietnam, makes industrial knives and blades. Thermal Spray Technologies in Sun Prairie, Wis., provides thermal spray coatings. Lineage Alloys Inc. in Baytown, Texas, produces thermal spray powder. And Lund Precision Products Ireland produces cutting systems for harvesting equipment and performs surface treatment for wear resistance. Overall, the Fisher-Barton Group has 950 employees, more than 715,000 square feet of combined floor space, and more than $200 million in annual sales.
Entering the Southeast
The company that started it all, Fisher-Barton Blades Inc. still stamps and heat-treats lawnmower blades in Watertown, Wis. During the past decade or so, FBSC grew its own blade manufacturing business until, in 2010, it was large enough to shift under the Fisher-Barton Blades operation, effectively consolidating the group’s blade manufacturing business. At the same time, FBSC began to delve into metal fabrication.
Although FBSC shares manufacturing space with Fisher-Barton Blades, it operates as its own entity. The facility essentially acts as two companies under one roof. If fabricated or stamped products need to be heat-treated, the company contracts out to Fisher-Barton Blades. Conversely, if the blade division has a particularly heavy-duty job requiring higher-tonnage presses with larger beds, it contracts with FBSC.
The South Carolina plant has roots in automotive and industrial stampings. “In the early 1990s it was a failing stamping company,” said Greg Andress, president of Fisher-Barton South Carolina Inc., hired shortly after the company purchased the facility in December 1993. “We bought the assets and basically turned the company around.”
The facility provided a foothold in the growing Southeast manufacturing base and a means to diversify beyond the lawnmower blade business. Today the 93,000-sq.-ft. plant is humming with about 110 employees.
A Line in the Sand
Although the company experienced solid growth, managers saw missed opportunity, and it generally had to do with a number: 20,000, sometimes 25,000. These annual part volumes represent an arbitrary cutoff point, a line in the sand that helps purchasers decide whether to pay for tooling in a stamping press. Lower than that, and they look to contract fabricators that can laser cut, punch, bend, and join without part-specific tooling.
At the other end of the spectrum, extremely high-volume stampings—especially for simple parts—had their own issues. With razor-thin margins, price per part measured in pennies, and volumes more than sufficient to fill containers on a shipping vessel, why not go overseas?
A Wisconsin native, Andress worked for fabricators there and saw their capabilities. Aside from welding fixtures and the occasional press brake job that required special tools, most jobs had no tooling investment—ideal for prototyping as well as low and medium volumes. That’s been the foundation of metal fabrication and, it could be argued, the reason contract metal fabrication exists as an industry.
But what about customers demanding thousands of formed parts or subassemblies a year, at or near that 25,000 line in the sand? This gray area has always presented trouble. A fabricator with an automated laser can produce plenty of blanks in short order, but the cycle times for bending and welding aren’t so short. What about being able to work with customers from initial prototype through production, seamlessly changing the manufacturing method to suit the volumes at different stages of the product life cycle?
About three years ago, plant managers decided to tackle this concept and began investing in metal fabrication equipment. Today the front end of the floor has a flexible manufacturing system from Mazak, including two 4-kW CO2 lasers, a 20-shelf tower, and a shielded exhaust system enclosing one laser that cuts stainless and aluminum. From there parts flow either to a 135-ton Durma press brake or to various hand-fed stamping presses (see Figure 3).
From there parts flow either to manual welding or to one of four ABB robotic weld cells with large work envelopes. Next the parts may go to heat treating, if required, or to final assembly before being shipped (see Figure 4 and Figure 5).
During the early stages of production, volumes may be low enough to warrant a pure fabrication routing: laser cutting, press brake bending, and welding. As volumes grow, it may make sense to laser cut the blank and send it to a stamping press with a forming die. This takes advantage of the laser’s blanking flexibility. Want less trimming? Just change the blank shape and reprogram the laser. As volumes grow more, the company may (depending on the blank shape and part complexity) move the job to a coil-fed stamping press or to hand-fed blanking and forming presses.
Selling Quick Response
Like many contract manufacturers these days, FBSC offers design assistance. For certain jobs, FBSC calls on the Fisher-Barton Group’s materials laboratory in Wisconsin to test new material concepts. Quite often the company consults with the prospect about the project and offers design advice before getting the order. “It’s a lot different from ‘Here’s my price,’” Andress said.
Andress described a recent situation in which an OEM about 80 miles away had a print for an assembly, one it had considered outsourcing to Asia. Could FBSC produce this? Andress got back in his vehicle, drove 80 miles back to his company, and presented the drawing to his engineers and tool and die personnel. “This was a major welded assembly,” he said. “We didn’t have any fixtures for it or anything else.”
Within two days they had cut the part on the laser, bent it on the press brake, and welded it. After that Andress got in his vehicle with the prototype in hand and presented it to the prospect—which soon became a customer.
He admitted that such prototyping speed isn’t always possible; it depends on material availability, part complexity, and tooling requirements for specialized forming, like deep drawing, that can’t be done on the press brake. But generally the shop uses its metal fabrication and tool-building capability to develop prototypes quickly and get its foot in customers’ doors.
According to the company, FBSC has the largest austempering heat-treat system in the Southeast. It does not sell heat-treating services to other fabricators or stampers, mainly because the process is proprietary and, especially for the blade business, a key competitive advantage. But it does sell the capability to customers looking for fabricated components or assemblies.
Andress presented this example: Say an initial design for a welded assembly calls for high-strength, low-alloy (HSLA) material with a yield strength of 50,000 PSI. A part with the same material thickness made out of 10B38, after austempering, can exceed 200,000 PSI.
“It allows us to reduce the thickness of the part,” he said. “Yes, they end up paying for the heat treating, yet they save weight, and so the cost really stays the same. We’ve taken weight out of it, we’ve added strength, and we didn’t do anything to the cost.”
Moreover, the reduced weight increases efficiency of the final product, be it from reduced fuel consumption or anything else, and decreases its cost of ownership. The result: The product becomes far more competitive in the market.
About Cycle Time
Robertson pointed to a part in the corner of his office. At one time the 0.125-in.-thick component required a press operator to manipulate it awkwardly to form nine bends. The part is not ordered in big volumes, but the lengthy forming times on the press brake made it a costly part for fabrication. “So we took it to our tooling guys, and they designed a die that can form this part in two hits,” he said.
“Every cycle of the press, a finished part comes off,” Andress added. “That allows us to win more parts, and when the competition tries to get this kind of job, they can’t, because they don’t have the presses to run them in.”
He added that in-house tool-building becomes critical here (see Figure 6). The equation boils down to this: A part can be formed on a brake at a rate of, say, 30 pieces an hour, and a stamping press can produce 150 pieces an hour. “You have a huge time savings to help pay for tooling,” Andress said. “And if we can build those tools in-house, which we do in many cases, the costs go down. The tooling is an expense, of course, but you can offset it by the reduction in labor.”
A Hybrid Approach
“If you think about it, everything in metal fabrication and stamping is a commodity, so you have to figure out how to do it better than the competition,” Andress said. “We’ve dubbed it our ‘hybrid’ process. We take the best of fabrication, the best of stamping, and put them together.”
The shop’s hybrid strategy boils down to three legs of a stool: design assistance, a mix of fabrication and stamping equipment, and tooling. Remove one leg, and the stool topples over.
The FABRICATOR is North America's leading magazine for the metal forming and fabricating industry. The magazine delivers the news, technical articles, and case histories that enable fabricators to do their jobs more efficiently. The FABRICATOR has served the industry since 1971.