Automotive Industry Trends
August 2004
The challenges of fastener finishing
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The finish of a fastener is critical to its function, durability and quality. Most fasteners are coated to protect against corrosion or to add qualities to the fastener, such as controlling the amount of torque needed to tighten it. Because fasteners are used on all parts of vehicles, each part requires different tolerances and criteria for quality, a challenging task for the industry. According to Brian Lowry, Vice President of Technical Services for Curtis Metal Finishing Company, trends in the fastener finishing industry reflect a number of different and sometimes conflicting forces that influence the automotive supply chain.
The greening of the auto industry
With corrosion protection a primary concern, the automobile industry for many years used cadmium electroplating for fastener coating because of its excellent anti-corrosion properties. Unfortunately, cadmium is also very toxic. In the 1990’s, cadmium (along with other substances such as lead and mercury) was banned from use in the automotive industry to prevent it from ending up in landfills.
Hexavalent chromium is also an excellent corrosion inhibitor. Recently, the European Union passed a directive that outlaws the use of chromium in any automobile part that will end up in a landfill, again because of the toxicity of the material. The directive was initially supposed to take effect in July of 2003, but the deadline for a complete chromium ban in automotive parts was extended to 2007. GM and Ford have set corporate goals of eliminating chromium components from all automobiles by July of 2005.
The auto industry’s requirement to fulfill government regulations impacts the mix of products available to fastener manufacturers and finishers. However, the auto makers still demand the same, or greater quality standards to be achieved in part performance, challenging finish makers to come up with better alternatives.
De-proliferation
According to Lowry, whose company is one of the largest fastener coating operations worldwide, a key driver in fastener finishing today is deproliferation, a movement in the auto industry to decrease the number of materials used in fastener finishes.
Because of a lack of standardization due to specialized requirements, fastener coating materials vary widely. Lowry describes an industry once driven by finish maker ingenuity. When new finishes would become available, engineers would try them and then build specifications from there. The result is that a wide range of finishes, with varying availability and differences in quality, get used in finishing. The varying availability causes problems in the automotive supply chain. The Big Three – GM, Ford and DaimlerChrysler – depend on just-in-time delivery of supplies and don’t warehouse parts, generally operating hand-to-mouth. Just-in-time delivery crunches the turnaround time for any producer in the automotive supply chain. By paring down the number of finishes used to six or seven, the Big Three hope to streamline and improve supply chain issues.
Of course, this paring is a double-edged sword for finishers. With the elimination of the most reliable anti-corrosion materials, cadmium and chromium, paring down limits potential options for finishing. However, the elimination of a wide variety of products does reduce turnaround time problems caused by varying supply levels of finishes.
Testing quality
With the passing of the Fastener Quality Act (FQA), which helped to impose standards on the fastener industry, changes have also come to finish testing. Lowry notes that the initial regulations required fastener makers to conduct a very high level of quality testing by salt spray, the industry standard for testing finish quality. The FQA requirements called for 42 days of testing before failure, causing a serious conflict with the just-in-time delivery requirements of automakers. It also created scenarios requiring fastener manufacturers to stockpile inventory while testing was in process. This testing requirement was modified, with a move to self-regulation and capability testing. Capability testing allows samples of the finish itself to be tested, which can then be used immediately to finish fasteners, without having to wait for parts to go through an extended testing period.
“Part and finish testing are both moving away from salt spray to performance, in-service testing,” says Lowry. The reason is that automakers do not consider salt spray to be a good measure of quality because of the controlled testing environment. Automakers are moving to more performance-based testing at proving grounds and in the field. As an example, Lowry cites GM, which takes cars to the maritime provinces of Canada, exposing them to a wide variety of the harshest elements a car could ever encounter. Each vehicle area – and the fasteners and fastener finishes in that area — have special requirements they need to meet for quality control purposes.
Combine all of these trends together – environmental concerns and regulations, finish restrictions limitations, standardization and testing – makes finding the right materials for fastener finishing more of a challenge than ever before. “If someone could develop a thin, dry, highly corrosion-resistant, cosmetically-attractive durable, metallic, chemical-resistant conductive finish that would offer accurate torque/tension performance and withstand temperatures over 1,000 degrees Fahrenheit, they could corner the automotive finishing market,” remarks Lowry. With no such finish available, finishers are challenged using combinations of different products to come up with quality alternatives.