As you plan a project, you may be asking yourself, “Are fasteners reusable?” If so, here are helpful tips from Fasteners, Inc. in Denver on how to determine if a fastener can be reused or not. It is always better to know ahead of time whether your fasteners are suitable to be used again or if a new set is required. Using compromised fasteners on any project will inevitably cause premature degradation, and the workmanship will be compromised. Read on to determine are fasteners reusable or not.
Fastener Drive Damage
The drive on a fastener is the slot, socket, hex hole or crossed slot in which a driver – your screwdriver, allen wrench, etc. – is used to apply torque while installing or removing. If this vital piece is damaged, the fastener cannot be reused. Sometimes, the driver will slip out of the fastener once the torque has exceeded a certain point. This is called camming out, and it can lead to permanent damage of the fastener, rendering it useless.
Avoid damage to the fastener by using a driver with appropriate torque. Too much torque will quickly deform the fastener. The drive, which is the slot and recess, needs to match the driver for best results. If you’re interested, you can check out the Industrial Fastener Institute, AMSE to learn about how deep a recess should be and just how far a driver needs to penetrate for the most effectiveness while driving.
Thread Wear
Deciding are fasteners reusable can depend on thread wear. Extreme thread wear can occur in machine screws that are continuously loaded and unloaded. The threads can become deformed with frequent use. This increases stress on the thread load and screw thread flanks. To reduce this damage, match up the right thread material to the finish. Additionally, use pilots, chamfers or full dog points to cut down on misstarts and wear due to cross-threading.
Metallurgical Fatigue
Fatigue will shorten the reliability and lifespan of a fastener. Prevent metallurgical fatigue by making the assembled joint rigid with regards to the spring rate of the fastener. Make sure that the service load is not greater than the preload. Know your type of fastener’s endurance limits. Replace them if that limit is approached and use magnetic particle inspection or liquid penetrants on assemblies in order to detect micro-cracks to avoid more issues.
Damage from Vibration
Vibration can cause several issues. It can loosen the fasteners, causing them to fall out, even get tangled with working components and cause severe damage. Otherwise, the constant movement back and forth can wear down the threads, loosening and causing fatigue. If you’re wondering, are fasteners reusable, vibration could greatly affect your decision.
Take a look at the assembly. In excessively vibrational areas, use non-metallic fasteners which have elastic attenuation in these areas instead. Additionally, supplemental locking features and self-threading fasteners can also help to dampen vibrations. These include locking washers, metal locking devices, locking threads, underhead serrations, commercial thread-locking adhesives, and plastic inserts and coatings.
Damage from UV Rays
Plastic fasteners can particularly suffer from UV damage, hence degrading and decreasing performance. Be aware of any plastic components used and be sure to provide adequate protection for them or choose another material altogether.
Seizing from Friction
The thread of your fastener can unintentionally weld to the assembly if the friction forces them together. Galling and seizing of the threads can render a fastener useless. Especially for stainless steel threaded fasteners, it is good to use a lubricator or anti-seizing compound to separate out the pressure flanks and bearing surfaces of the fastener you are using. Or choose non-galling metallurgy mating threads instead.
Seizing from Heat and Corrosion
Avoid using dissimilar materials and fasteners. Otherwise, the fastener’s threads can seize from either corrosion or too much heat. Varying thermal expansion coefficients will inevitably lead to seizing. Ensure adequate clearance and use anti-seizing compounds and temperature-appropriate thread lubricants.
Corrosion
When deciding are fasteners reusable, this is a big one. The corrosion of a fastener’s working surface can lead to their disuse or complete failure which is a dangerous possibility. Corrosion occurs regularly when elements including sodium, sulfur, and chlorine combine with the moisture in the air to form hydrochloric acid and other acidic compounds.
Reduce the risk of severe corrosion by using corrosion-resistant fastener materials. Also, avoid corrosion by limiting the use of dissimilar elements in the close range of the assembly. Thus, you can reduce the galvanic coupling levels and lower electrochemical potential differences, which inevitably lead to corrosion. Additionally, use sacrificial coatings on the fasteners and the assemblies at risk of corrosion. These coatings will corrode first and leave the structural part of the fastener and the assembly intact.
Debris
Recessed drives (socketed, Philips, Freason, Pozi-Drive) are susceptible to the build-up of debris. Anything from grease to grit and more can find its way into the drive space and create issues while doing so. The transmission of torque is massively reduced if there is an obstruction present. Conduct tests of tightening and untightening before deciding on the specific fastener to use for your project and to avoid prematurely camming out.
Store fasteners in a location free of debris if possible. If not, use a lubricant or protective grease that will easily flush out of the fastener before driving.
Losing Locking Ability
It’s essential to document the precautions, procedures for fasteners with locking features and have their performance laid out and passed down to anyone working on the project. Thread-locking adhesives, lock washers, locking tabs, self-locking threads, are rendered useless if installed incorrectly, even just one time. The need for threads to be clean, burr-free, and intact are essential points to understand.
Hopefully, now you can answer the question “Are fasteners reusable?” with help from our re-using fasteners guide. Remember to use Fasteners, Inc. as your resource for anything concerning fasteners of any kind. We are here to help with an incredible pool of knowledge and experience. Do not hesitate to contact us about your upcoming fastener needs this year.
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