What's the thought on re0using nylon insert nuts? They seem to be okay, but part of me thinks that once they are used,they'll never be as good a second time. Any thoughts? Also, is there a Loc-***e type of product that really keeps the nut from loosening? Thanks for the help.
The green Loc***e....be sure you don't want to ever take it apart before using. That or bearing mount...it's also green. Nylocks are never as good the second time around.....but still won't spin off "by hand" unless reused alot.
I would re-use a nylock on most areas except for crucial areas such as steering components. Torque is the more important factor in hardware. Loc***e thread locker does work good but you must use the rated color. I'm in the aircraft world and loc***e is used daily.
I've reused the nyla-nuts before with no problems. and there are different degrees of loc***e some are really strong and will be a ***** to remove.
when i was working construction we always waxed the threads of the bolts when using nylock nuts, incase we had to take it apart. never tore one up
I personally never re-use Nylocks once they have been in service. As far as loc***e goes depending on application you need to use the correct color. Go to the loc***e website for an explanation of the different colors and there applications. Very interesting reading. Scott
We use lots of nylock nuts at work, food industry. They are never as good the second time but seem to work. I personally would not use them where strength is a factor, I've never seen a grade 8 nylock. Don't think a torque value would be the same either. Just good for vibration, IMO.
If you, or anyone else here is serious about his, and fasteners in general, you need this book - it is the bible for race car builders when it comes to nuts and bolts http://www.amazon.com/Fasteners-Plumbing-Handbook-Motorbooks-Workshop/dp/0879384069
Nylon inserts are good to use until you can loosen it with your fingers. They are used on aircraft. And make sure you use them on the same bolt because they are set for that particular bolt. We used the red Loc***e in the Air Force.
According to the manufacturers we use in the food industry, nylocs can be threaded three times before they are no longer considered good.
After an R&R on the transmission in my dirt car for maintenance, our "I wanna help buddy" volunteered to get back under the car and bolt the handle back onto the shifter. "Dam Rick, how long does it take to put in 2 bolts & nuts?" It wasn't until I pulled the shift handle back out weeks later that I found that, though it took him a while, he installed the nylocks backwards.
I used to work a a GM dealership in the parts department - we had one mechanic who absolutely would NOT re-use any kind of clip, retainer, cotter pin, lock-nut, etc. Some of that **** was hard to find - use to drive us cuckoo for cocoa puffs.
On sprintcar we reuse them as long as they cannot be screwed together with fingers as someone else said.I have melted the end with a lighter when I have to reuse a worn one.
Here is a link to a pretty good read on the subject: http://www.streetrodderweb.com/tech/1005sr_locking_fasteners_myths_procrastination_something_new/index.html Kind of a long read, but lots of good info. I think, like anything else, that good common sense should be your guide. Hope this helps Dan
If I had to reuse them and wanted it to come apart again, I'd apply RTV to the threads. You can get it off, but I doubt if it would do so on it's own.
On nylon threads, thread lock is not necessary. That is the purpose of the nylon, it locks on it's own.
I work for Fastenal and we get these tech questions all the time. There is not a locking nut, either nylock or top lock that should be re-used. Can you? Yes, but like one guy said earlier in non critical situations. I also have become good friends with the Loc***e rep and we go on lots of sales calls together and I have learned tons of info. I use Loc***e on almost everything now for corrosion prevention. Rust needs air and moisture to grow but if you use Loc***e it actually fills the void in the tolerances btw the nut and bolt. So even a non coated bolts which rust pretty fast if not oiled will not rust where the are mated together. Also some people complain that the red doesn't even hold sometimes. Just until recently Loc***e came out with a red and blue primerless version that does not require a primer prior to application. I think the new number is 263 instead of 262 or close to it. So if you put red Loc***e on plain oiled bolt it's like trying to mix oil and water and it will not hold at all. If you having vibration problems check out the Nord-loc washers they are more expensive but do a great job and can be re used over and over.
Rule of Thumb , Basic first rule is if you can tighten the fastener by hand it's NFG! , If you need to bolt together a steering shaft, use a mechinal fastener. (pinch nut) A Lock nut resists turning. Usually nuts are free spinning, but locknuts nuts have a plastic patch that causes resistance to nut turning. This resistance is called "prevailing torque". Prevailing torque is the torque required to turn the nut. None of the prevailing torque goes toward tightening the bolt. Lock nuts nuts fall within a group of nuts called 'lock nuts" Lock nuts come in all types and sizes. Typically there are the "Nylock" or elastic stop nuts, and the "all-metal" lock nuts. The rule of thumb is to add the prevailing torque to the torque value when torquing a lock nut. This is because the prevailing torque doesn't contribute to bolt tightening. It is just friction that needs to be overcome. For example, a Grade 5 1/4-28 bolt in tension lubricated zinc plating, with a torque of 10.5 lb. ft. produces a clamping load of 2,511 pounds. If we use a use a lock nut that takes 2 lb. ft. of torque to turn, then 2 lb. ft. of torque is used in turning the nut leaving only 8.5 lb. ft. for bolt tension. Our clamping load is reduced to 2,009 pounds. If, however, we take our original torque of 10.5 and add the 2 that the Nylock requires and set our torque wrench to 12.5, our clamp load is 2,511 pounds. The same as it was without the nylock. You can use your torque wrench to measure lock nut torque and then add this value to the bolt's required torque. Prevailing torque calculation should be done with your nut and your bolt using your thread lubricant. Published prevailing torque charts may give you an idea of how much torque is used up by the nut's locking feature, but in actual conditions, the results will vary. There is an interaction between the bolt threads, nut locking feature, and the thread lubricant (whether liquid or plating) that makes each prevailing torque calculation unique. --exceptions to this rule---- Usually you wouldn't add prevailing torque to the torque value published by the equipment manufacturer. The equipment manufacturer has already done this for you. For example, propeller bolts use elastic stop nuts (prevailing torque nut). The propeller manufacturer is aware of this. So just go ahead and use the published torque values. If you use a different nut or a different thread lubricant than what the manufacturer specifies, then the proper torque is unknown. Taken from this forum. http://www.mechanicsupport.com/Nylock_nut_torques.html http://www.mechanicsupport.com/stop_nut.html
Per FAA AC43-13-1B f. 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 selflocking nuts are not installed in areas where temperatures exceed 250 °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.) TABLE 7-2. Minimum prevailing torque values for reused self-locking nuts. FINE THREAD SERIES THREAD SIZE MINIMUM PREVAILING TORQUE7/16 - 20 8 inch-pounds 1/2 - 20 10 inch-pounds 9/16 - 18 13 inch-pounds 5/8 -18 18 inch-pounds 3/4 - 16 27 inch-pounds 7/8 - 14 40 inch-pounds 1 - 14 55 inch-pounds 1-1/8 - 12 73 inch-pounds 1-1/4 - 12 94 inch-poundsCO**** THREAD SERIES THREAD SIZE MINIMUM PREVAILING TORQUE7/16 - 14 8 inch-pounds 1/2 - 13 10 inch-pounds 9/16 - 12 14 inch-pounds 5/8 - 11 20 inch-pounds 3/4 - 10 27 inch-pounds 7/8 - 9 40 inch-pounds 1 - 8 51 inch-pounds 1-1/8 - 8 68 inch-pounds1-1/4 - 8 88 inch-pounds If the FAA says as long as it meets prevailing torque, it can be reused, then I will reuse it. It won't hurt to reuse them on a car.
If you put a cold chisel across the top of a nyloc and give it a light tap with a hammer, just enough to slightly deform the nylon insert, you can get a bit more grab out of them if you need to re-use them. Pete
well in the aviation industry you NEVER reuse fiber lock nutz- once they are cut they loose the ability to grip sufficently.. but unless yer taken your rod up to 10000 ft. they should work till your tie rods fall off
Sorry, that was really two different question. And, thanks for all the advice in general. I'm think, for the money, I'll just =use new ones.
Watch this video. The guy talking is boring but this explains everything with visual, and scientific proof. It makes nylocks look useless. You will be awed!! Copy & paste: http://www.youtube.com/watch?v=mgwmuZuJ02I&feature=youtube_gdata_player
It may look useless but I have been using these nuts for years in many different aviation applications, from Cessnas to F-15's, and not once had an issue.
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