Design News for Mechanical and Design Engineers

One of the casualties of the retrenchment was the delivery schedule for the Dreamliner, which was extended due to inadequate production capacity at Alcoa Fastening Systems in Torrance, CA.

Today, it’s clear the American fastener industry is dramatically changing. The wild success of the Boeing Dreamliner program is one factor. Another is the drive by manufacturers to boost productivity, requiring far superior fastening systems. Other drivers are the push to light weight vehicles and miniaturize electronics. And meanwhile, low-cost fastener producers from Asia and Eastern Europe have taken hold of the low end of the fastener business.

Domestic fastener producers are moving to technology to survive. They are substantially increasing design capabilities and offering improved design services.

What it means to design engineers:

• Expect your fastener suppliers to push the envelope on design concepts.
• Ask tough questions about how your suppliers can help you reduce component weight and increase product life.
• See how costs can be cut through processes such as coring, gas-assist injection molding and novel materials combinations.

At the same time you’ll need to pay special attention to supply chain issues, as Boeing painfully discovered last year when even simple fasteners could not be shipped on time for the ambitious 787 program. That’s because domestic capacity has been cut for large-volume manufacturing of commodity products. Another factor was spot shortages of titanium, an increasingly important fastener material.

Prototyping’s Rise

One example of the shifting tide of American fastener production is Southco, which first began manufacturing specialty fastener devices in Essington, PA in 1945. Last year Southco announced plans to close its Brandywine Manufacturing facility in Concordville, PA. Products and technologies are being transferred to Honeoye Falls, NY, Rockledge, FL, Chihuahua, Mexico and Fu Wang and Shanghai, China. Output from Southco’s four Chinese plants rose 40 percent last year. An assembly center is now operating in the Czech Republic.

And what’s happening in the United States? Soutcho is creating a Rapid Prototype and Injection Molding Center of Excellence at the Concordville plant.

“Applications that used to have a life of three years, now have a life of just one year,” says Southco’s Gerry Clisham, explaining the investment in the rapid prototyping center. “One driver is more frequent design changes. Others are the drive to miniaturization and light weighting. With the need to reduce weight, design engineers are looking more at custom latches to meet the requirements.” Clisham is global product manager at Southco.

The rapid prototyping center will start with 30,000 sq ft of dedicated space with room for expansion. It will include fused deposition modeling (FDM) equipment as well as CNC lathes and mills, a turret press and brake and product testing capability.

“One thing that is driving this is our positioning control devices,” says Clisham. “You’re worried not only about the closed position of devices, but also the open position. This has become a custom type of business. We’ve gotten involved in a number of applications where the annual usage never exceeds 200 pieces.”

In a sense, Southco is developing the capabilities of a job shop that can also create sophisticated design. Those novel design ideas often get built into standard designs in two years when Southco can throw the job over the wall to its volume production operations. That’s the plan.

Another old-scale fastener manufacturer based in Pennsylvania is also ready for change.

R&D on Steroids

PennEngineering of Danboro, PA traditionally introduced two new products a year. Two years ago development efforts were ramped up to roll out four new products annually. This year, the target is six. “Some of the new products expand existing lines and some are completely new,” says Brian G. Bentrim, manager of Global New Product Development for PennEngineering. One example is the spinning clinch bolt for thin metal panels that use controlled clinching action to captivate the screw while allowing it to spin freely in the sheet. The result is quicker attachment of mating hardware by eliminating a need for loose fasteners such as screws and retaining clips or washers. The one-piece steel fastener further offers an extremely low-cost alternative to expensive multi-component hardware assemblies.

PennEngineering has doubled the number of engineers in its product development group in the last year, including the creation of a design team in China.

”One of our design goals is to expand our product line into micro fasteners,” says Bentrim. “We’ve started with some custom products to get our feet wet, but we’re going to be coming out with some standard products in the future.” Target applications include handheld electronic devices and cellphones.

K.A. Swanstrom founded Penn Engineering & Manufacturing Corp. in 1942, with four machines in a Doylestown, PA garage. The company was built on his idea for self-clinching fasteners for metal sheets too thin to be tapped. That idea remains the core business at PennEngineering as companies continue to adopt simpler, easier-to-assemble designs. One of the new trends is development of stainless fasteners for thin stainless sheet.

There’s also a trend toward more specialty materials in fasteners at Avdel, an Acument Global Technologies company. “We’re always looking for new materials that are headable and treatable,” says Pete Beecherl, manager of product and application engineering at Avdel. “Take the self-piercing rivet as an example. “It creates a  hole in one sheet and then flares into the next sheet. It has to be stronger than the material it is going through.” Avdel is using a new proprietary stainless alloy that meets the requirements.

The push for new technology at Avdel is necessitated in part by the rise of Asian manufacturers, who reverse engineer American and European designs and then clone them. It’s alleged even trademarks are stolen at times. “The challenge for us is to develop new technology so that we can always stay ahead of that curve,” says Beecherl, commenting that Avdel is reinvorgating its technology center in England.

Smaller fasteners for the computer industry are under development. “Blind fasteners are used a lot in the chassis of computers,” says Beecherl. “They are using thinner materials as products become more compact and it’s a challenge to develop fasteners that are flush on cosmetic sides. “That pushes the envelope for use on how small you can go.”

Reports of supply chain problems in the Boeing Dreamliner program overshadowed significant technical developments. Assembly design issues in the aircraft industry generally seem like an order of magnitude higher in difficulty than in traditional white goods or automotive industries.

“Ten years ago a new design might move from the back of a napkin to mass production in four to six years,” says Rick Sharpe, senior vice president, customers and marketing for Alcoa Fastening Systems. “We literally have cases today where OEMs and their partners are trying to order systems while we are still designing them. That is a testament not only to the vast improvements the new products offer, but to the challenging design space in which we play today.”  

The Dreamliner Effect

Clearly, the wild success of the Dreamliner and the generally strong state of aircraft production in the United States is a major factor in the emerging resurgence of the domestic fastener industry.

Case in point: The North American Business Unit of Acument Global Technologies is making a major new investment for the aircraft business, which it only recently re-entered after a long hiatus. Acument is building a factory in Rockford, IL to supply the Dreamliner and other new aircraft platforms.

“Our research has shown a tremendous gap between supply and demand for fasteners in the aircraft industry,” says Martin Schnurr, vice president and general manager. The gap is both in supply and in the need to improve productivity, particularly for composite-bodied planes, such as the Dreamliner.

Acument (then Camcar Textron) introduced a new drive system to Boeing called Torx Plus three years ago. Torx is a screw head with a six-point star-shaped pattern. Torx Plus allows greater torque to minimize wear. This speeds initial assembly and allows fast removal of fasteners for maintenance. Acument has added three new design engineers for its aerospace initiative.

“We are in a technology business, and we are not going to compete on commodity products,” says Schnurr. “Quite frankly this is about survival. In the last two years, we have introduced 10 key products for fastening.”

For automotive applications, the company introduced The Torx Plus Max, in which the stem end of a threaded fastener is held steady while a nut is rotated. “It’s usually used in drive train applications where you can’t get to the head of the fastener,” says Acument’s Larry Pickett. “It allows one assembler to hold down the end of the fastener while torqueing down a nut.”

For electronics, a special lubricious polymer coating allows assembly of disc drives without creating debris.  “As you get smaller and smaller fasteners you begin to move beyond the capability to drive the fastener with the recesses that are available in the marketplace,” says Tim McGuire, executive director, technology for Acument. “You have to invent smaller recess and boost the lubricity of the coating.” Acument produces the disc drive fasteners at a plant in Decorah, IA and ships them to Asia.

Aircraft Materials

Materials growing in importance for assembly applications in aircraft include titanium, aluminum lithium and other alloys under development at the Alcoa Technical Center outside of Pittsburgh and elsewhere.

Increasingly, assembly systems are become systems-oriented. Not surprisingly, this trend is most apparent in aircraft.

“The new generation of fasteners we have introduced on the 787 program are a key part of an energy management system in addition to their ‘normal’ responsibility to hold structure or systems together,” says Sharpe. “This is really the first time that a fastener has been called on to do more than one thing, and we believe it is just the beginning.”

Another Alcoa innovation is the Eddie-Bolt two-pin fastener optimized for composite applications. The system has five flutes equally spaced along a portion of the pin thread area, along with the matching Eddie-Nut, which has three equally spaced lobes. When installed, the lobes of the nut are deformed into and across the pin flutes and threads, creating a positive mechanical lock. The optimized thread length, in conjunction with the controlled run out on the transition zone of the pin, permits a decrease in overall pin length and nut height, resulting in a reduction of weight. These features assure static and dynamic strength properties of the fasteners while providing a vibration-resistant positive mechanical lock of the nut to the bolt.

		New injection molding capabilities are evident in this electronic glove box latch.
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