It’s not uncommon for manufacturers to overlook the importance of incorporating high-quality fasteners within their product designs. Whether it’s choosing nuts, bolts, screws, washers, anchors, or rivets, these hardware devices are critical for affixing two or more parts, materials, or objects. Here are five common mistakes to avoid when choosing fasteners.
1. Choosing Price Over Quality
It’s easy to get enamored by the potential savings of using low-priced fasteners. Reducing the costs of new product designs increases profit. Unfortunately, the savings on low-cost fasteners are quickly eroded with longer assembly cycle times in production. Even if the fasteners pass the final QC inspection, it’s more than likely they’ll fail in the field once the customer uses the product.
2. Using the Wrong Fastener for Your Design
Using the right fastener in design is critical to ensuring the integrity, strength, rigidity, and durability of your finished part. That selection must be based on the types of materials you’re using and the types of parts or sub-assemblies you’re joining or connecting. In many instances, it’s a question of product safety. Using the wrong fastener or wrong fastener material can make your joints susceptible to cracking, bending, or buckling.
3. Dissimilar Metals in Your Bolted Joint (Galvanic Corrosion)
Galvanic corrosion occurs when two different metals are exposed to water. One metal becomes the reducing electrode (anode), while the other becomes the positive electrode (cathode). These two create an electrochemical reaction that eventually leads to galvanic corrosion. This is a common occurrence for finished goods exposed to elements like moisture and humidity where the fastener material is different from the base material.
4. Incorrect Torque
In layman’s terms, incorrect torque refers to either over-tightening or under-tightening fasteners. The goal is to find the ideal amount of clamping force to ensure the joints or parts remain secured without breaking, cracking, or failing. When the tension is too high the fasteners become stressed and can tear, rip, or break. When the tension is too low, excessive vibration leads to the fasteners becoming dislodged or loose.
5. Wrong Grade of Material
Fasteners can be made of plastic, composites, brass, steel, titanium, aluminum, chrome, carbon steel, etc. However, choosing the wrong grade of material can lead to your product’s premature failure. When choosing your fastener’s grade, think about the grade’s mechanical properties in terms of its tensile, fatigue, and shear strength.
Aside from the grade’s mechanical properties, it’s also important to understand how that material reacts under different environmental and operating conditions. Industrial finished goods are often exposed to corrosive environments. Without the proper coating, fasteners can easily corrode. Galvanized, nickel-plated, brass, and zinc-plated are just some of the coating options that help to protect fasteners from corrosion.
Making the Right Choice
Don’t make the all-too-common mistake of glossing over fasteners in your design. Use low-quality hardware or assume that all fixtures are the same, and a failure is more than likely. The right hardware ensures your non-permanent joints remain intact. In the end, it’s about the integrity of your finished good and your company’s reputation.