Author:
Optimas Solutions Mike Eusanio, Automotive Applications Engineer, and Bob Mangapora, Automotive Business Development
Date
11/20/2024
PDF
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Figure 1: Grinding fasteners to perfection is part of the process when manufacturing custom fasteners for assembly
Optimas and other key players in the fastener industry are at the forefront in reducing vehicle weight to enhance mileage, leveraging innovative technology, superior engineering practices, and a fresh perspective on weight reduction from a component standpoint to assist manufacturers in meeting these standards.
Despite this, the fastener is typically the last component considered after the significant components are designed, limiting the possibilities for innovation. By involving the fastener supplier early in the design stage, you unlock the potential for transformative innovations, leading to optimized performance, reduced component size, and a notable improvement in lightweighting capabilities.
What the Engineering Experts Say
Two of our leading engineers and automotive experts, Mike Eusanio, Automotive Applications Engineer, and Bob Mangapora, Head of Automotive Business Development, sat down with Power Systems Design to discuss how engineered fasteners introduced early in the design process can significantly impact vehicle performance and sustainability measures. Below is an abbreviated version of the conversation:
What is the Benefit of Using Engineered Fasteners?
While using existing fasteners might be advantageous from a sourcing perspective, it often falls short in terms of weight and performance. Incorporating engineered fasteners early in the design process offers several benefits. These custom fasteners are tailored to the specific requirements of the design, eliminating unnecessary features and materials typically found in standard fasteners, which are designed for broad applicability. By opting for engineered fasteners, manufacturers can enhance efficiency and performance, using only what is truly needed rather than adapting a standard fastener to fit an existing design.
How Can Reducing Fastener Size Offer Weight Reduction Benefits Beyond the Obvious 'Smaller Equals Lighter' Effect?
"The size of a fastener is usually one of the first things we look at when helping with lightweighting," said Eusanio. "For instance, knowing the design loads early in the process allows for a thorough joint analysis to determine the precise requirements for fastening. This could mean opting for an M6 fastener instead of an M8, or even using a higher-strength M6 bolt in place of a lower-strength M8, provided the design parameters are well-understood."
Optimas offers software equipped with a VDI 2230 design program that models joint performance. This tool predicts potential failures by adjusting parameters such as fastener size and strength, allowing for real-time modifications and analysis of the joint's ability to maintain integrity under known or estimated service loads and installation methods.
Utilizing smaller fasteners can also reduce installation space, leading to lighter and more compact products. Lighter tooling requires less material and simplifies handling for both human and robotic operators, which can increase production rates.
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Additionally, smaller products can offer substantial cost savings by reducing raw material use and shipping expenses, presenting a favorable outlook for manufacturers. Optimized fasteners not only aid in weight reduction but also contribute to material waste management, space efficiency, and environmental sustainability. Understanding the design requirements of fastened joints helps avoid overdesign and unnecessary weight, enhancing overall production efficiency and environmental responsibility.
What fastener materials are best suited for achieving enhanced lightweighting?
Advancements in fastener materials can significantly contribute to weight reduction beyond just choosing smaller components. Steel isn’t always necessary; high-strength aluminum alloys, for instance, can replace steel in certain applications, offering substantial weight savings without compromising clamp force.
"By understanding material properties, fastener functions, and joint design principles, engineers can effectively navigate the challenges of switching fastener materials," said Magnapora. "Our software tools can help optimize material choices, allowing for thinner or smaller mating components."
"Engineers are increasingly replacing metal components with plastics," Magnapora continued. "This shift often requires using fasteners designed to minimize clamping force to prevent damage to the plastic. A popular solution is the hex flange head bolt, which distributes load more evenly across the plastic."
For plastic parts, compression limiters—small tubes that provide strength comparable to steel joints—or shoulder bolts can prevent damage while securing the joint. Rivets can also be used as a lighter alternative to heavier fasteners.
"Components that were once stamped can now be welded or cast, eliminating the need for multiple parts," added Magnapora. "Lightweight castings offer significant weight savings and improved tolerance. Thread-forming screws can be used directly in castings, and a range of fastener options is available through Optimas."
Incorporating fastener manufacturers early in the design process is crucial for accessing the best options and leveraging software tools for effective lightweighting.
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How does adjusting fastener geometry contribute to weight reduction in component design?
Fastener geometry can be finely tuned to reduce weight without compromising performance. By adjusting geometry, you can pair fasteners with materials to offer diverse fastening solutions.
One effective strategy is to use specialized fasteners to enable lighter mating parts. Eusanio shared a recent example: “A customer wanted to reduce the thickness of their structural members for weight savings. By collaborating with Optimas, we switched from a ¼" thread to an M6, allowing for thinner materials while maintaining structural integrity. We also improved corrosion resistance and aesthetics. The key benefit was the significant reduction in overall weight by using thinner mating stampings.”
“For fragile sheet metal assemblies, the Fastite 2000 offers a dual lead thread form and underhead features that allow for even thinner materials,” continued Eusanio. “This design helps prevent thread stripping and supports weight reduction.”
Specialized fasteners, like those for tapping plastic or unique thread forms, can also be used to redesign components from metal to plastic. Optimas Manufacturing offers various special thread forms to facilitate this transition.
“Innovative head designs, such as the Fastenlite, remove up to 29% of the head’s weight compared to traditional hex flange heads, reducing material use and cost,” added Mangapora. “Additionally, designing fasteners to functional sizes rather than standardized lengths can optimize material usage and tooling efficiency.”
Considerations for geometry include:
Adjusting fastener geometry is a crucial aspect of designing lightweight components, impacting both weight and performance.
“How does reducing the quantity of fasteners impact vehicle weight and overall design efficiency?”
Reducing the number of fasteners is a straightforward yet crucial method for decreasing vehicle weight and enhancing design efficiency. Fewer fasteners can streamline design, improve operation, and maintain structural integrity.
"As designs evolve, additional features and fasteners often accumulate," explained Eusanio. "Many companies end up with redundant fasteners because they don't revisit their BOM to consolidate parts. So, through engineering, we show them a group of fasteners that are all similar in function and suggest standardizing them based on the lowest-cost item."
For instance," Eusanio elaborated. "Our engineers collaborated with a customer on redesigning a product for their next-generation model. By standardizing based on part attributes and working closely with the customer’s design team, we streamlined the design, reducing approximately 180 part numbers down to just 40. This not only simplified production but also drove significant cost and efficiency gains.”
In our system, we catalog fasteners by detailed attributes—thread size, type, head style, material, and length—allowing us to swiftly analyze and streamline a customer’s part list,” Eusanio explained. “We often uncover redundancies, such as 12 variations of M8 screws with slight length differences or different head styles, which are essentially the same part. By identifying these overlaps, we help customers simplify their inventory and reduce costs significantly.
Rationalization programs can drastically cut the number of fasteners, impacting production efficiency and product performance. Early re-evaluation and consolidation of fasteners lead to significant weight savings, cost reductions, and improved vehicle performance.
Conclusion
Incorporating quality engineering from the outset can transform vehicle design and performance. As highlighted by experts Mike Eusanio and Bob Mangapora, early integration of engineered fasteners can lead to substantial improvements in fuel efficiency, emission reductions, and overall cost savings. By addressing fasteners early, manufacturers can leverage innovations in material science, geometry, and quantity reduction to achieve optimal lightweighting and performance.
Don't let fastener choices be an afterthought. Engage with fastener experts early in your design process to unlock potential innovations and drive your next-generation vehicle design forward.
