Reusing AN nuts and bolts? - Zenith Aircraft Builders and Flyers2024-03-28T08:37:49Zhttps://zenith.aero/forum/topics/reusing-an-nuts-and-bolts?commentId=2606393%3AComment%3A862282&feed=yes&xn_auth=noBolts can be reused as long a…tag:zenith.aero,2022-02-27:2606393:Comment:8625432022-02-27T15:33:42.387ZTonyhttps://zenith.aero/profile/Tony
<p>Bolts can be reused as long as nothing is wrong with them (deep gouges, cracks, etc). Nylock nuts go in the trash after their first use.</p>
<p>Bolts can be reused as long as nothing is wrong with them (deep gouges, cracks, etc). Nylock nuts go in the trash after their first use.</p> Nick,I think your best source…tag:zenith.aero,2022-02-21:2606393:Comment:8621092022-02-21T14:24:57.895ZEarnest Fontenothttps://zenith.aero/profile/EarnestFontenot
<p>Nick,<br></br>I think your best source of information to help you decide is AC43.13. This can be downloaded for free from the FAA.</p>
<p>AC43.13-1B States:<br></br>"Fiber or nylon locknuts are constructed with an unthreaded fiber or nylon locking insert held securely in place. The fiber or nylon insert provides the locking action because it has a smaller diameter than the nut. Fiber or nylon self-locking nuts are not installed in areas where temperatures exceed 250 degrees F. After the nut has been…</p>
<p>Nick,<br/>I think your best source of information to help you decide is AC43.13. This can be downloaded for free from the FAA.</p>
<p>AC43.13-1B States:<br/>"Fiber or nylon locknuts are constructed with an unthreaded fiber or nylon locking insert held securely in place. The fiber or nylon insert provides the locking action because it has a smaller diameter than the nut. Fiber or nylon self-locking nuts are not installed in areas where temperatures exceed 250 degrees F. After the nut has been tightened, make sure the bolt or stud has at least one thread showing past the nut. DO NOT reuse a fiber or nylon locknut, if the nut cannot meet the minimum prevailing torque values. (See table 7-2.)"</p>
<p>Taken from AC43.13-1B, Chapter 7, Section 4. NUTS, Paragraph 7-64 f. Found on page 7-11.<br/>The prevailing torque values table is on the next page.</p>
<p>I went online to look up the definition of Prevailing Torque.<br/>I found:<br/>"Prevailing torque is the amount of torque needed to run a nut down a thread on nuts that are designed to resist self-loosening under vibratory forces."</p>
<p>Hope this helps,<br/>Earnie</p> My practice is not to reuse n…tag:zenith.aero,2022-02-20:2606393:Comment:8622822022-02-20T16:43:03.395ZDaniel Niendorffhttps://zenith.aero/profile/DanielNiendorff
<p><span>My practice is not to reuse nylock nuts. There is a spec on the ability to reuse them - but my recollection is that it is cheaper and easier to just keep a stock of common size nylock nuts and replace them. I don’t recall how the spec stated to measure the remaining nylock holding drag, but I do remember thinking it was a pain. As far as bolts go, I believe the AN series bolts stretch ever so slightly when properly torqued (like many automotive head bolts) - once past a critical…</span></p>
<p><span>My practice is not to reuse nylock nuts. There is a spec on the ability to reuse them - but my recollection is that it is cheaper and easier to just keep a stock of common size nylock nuts and replace them. I don’t recall how the spec stated to measure the remaining nylock holding drag, but I do remember thinking it was a pain. As far as bolts go, I believe the AN series bolts stretch ever so slightly when properly torqued (like many automotive head bolts) - once past a critical stretch the strength drops off extremely quickly……. So I would not reuse a bolt that has been torqued. And that goes double if someone else did the torqueing - as overtorque can immediately compromise the bolt. And overtorque is a common error.</span></p> I believe that AC43.13 states…tag:zenith.aero,2022-02-20:2606393:Comment:8620302022-02-20T15:10:24.550ZDon Morriseyhttps://zenith.aero/profile/DonaldMorrisey
<p>I believe that AC43.13 states nylon lock nuts can be used 3 times. However how would you ever keep track of that over time? For the cost of a new nut you can have peace of mind. Personally I never reused a locknut, always a new one. Since you will be remounting the wings and they'll probably be staying on for a long time, I would replace all the bolts too. Bottom line is you don't know if the previous owner was reusing hardware, so I would definitely go with new.</p>
<p>I believe that AC43.13 states nylon lock nuts can be used 3 times. However how would you ever keep track of that over time? For the cost of a new nut you can have peace of mind. Personally I never reused a locknut, always a new one. Since you will be remounting the wings and they'll probably be staying on for a long time, I would replace all the bolts too. Bottom line is you don't know if the previous owner was reusing hardware, so I would definitely go with new.</p> Nick,
Someone more knowledgab…tag:zenith.aero,2022-02-20:2606393:Comment:8622032022-02-20T13:15:34.200ZDarrell Doerhoffhttps://zenith.aero/profile/DarrellDoerhoff
<p>Nick,</p>
<p>Someone more knowledgable than me will probably chime in here, but it's my practice to replace locknuts in any place that, if it comes loose will be a safety issue. I think your wing attachements fall into this category.</p>
<p>I teach a high school aviation class, and in one lesson, I have the students study the crash of Galloping Ghost at the 2011 Reno Air Races. The NTSB concluded that reused locknuts contributed to this crash that killed several people.</p>
<p>Nick,</p>
<p>Someone more knowledgable than me will probably chime in here, but it's my practice to replace locknuts in any place that, if it comes loose will be a safety issue. I think your wing attachements fall into this category.</p>
<p>I teach a high school aviation class, and in one lesson, I have the students study the crash of Galloping Ghost at the 2011 Reno Air Races. The NTSB concluded that reused locknuts contributed to this crash that killed several people.</p>