DIY Locknuts





Introduction: DIY Locknuts

Locknuts are great because they resist loosening from vibrations and torque. They offer an all in one solution to keeping bolts on tight (no lock washers, threadlocker solution). But what if you don't have any locknuts?

This Instructable will illustrate the steps to transforming any nut into a locknut. It is simple, easy and might save you a trip to the hardware store when you are in the middle of a project.

Step 1: Materials

You will need these materials:

  • nut(s) that you want to make into locknuts
  • glue- I have tested CA glue and rubber cement with success
  • toothpick or cotton swab

Step 2: Apply Glue to Threads

Start by cleaning off the threads on the nuts to make a quality bonding surface for the glue. Use a toothpick or cotton swab to apply a dab of glue to the nut. The glue should be retained to one half of the nut- if you cover up all of the threads, it will be hard to start a bolt.

Depending on how much holding power you desire, you can either put a small drop on the threads, or cover an entire half of the nut. When you have finished applying the glue, set the nut on end and allow to dry per glue instructions.

Step 3: Use!

Once the glue has dried, try threading the nut onto a bolt. You should find that it is very hard to tighten- you will probably need a wrench. If you are still able to hand tighten the nut, add more glue and try again. Anything more than hand tight should be able to resist most vibrations and stray torque.

I noticed when I was experimenting with these homemade lock nuts that it is best if you do not mess with them more than necessary. The more you loosen/tighten the nut, the less locking power it will have. The glue will start to wear off after a couple of times threading.

Thanks for reading this Instructable. Let me know if you have any suggestions or questions.

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    84 Discussions

    I have been using this stuff recently called bondic. Its like glue but only hardens under uv light. And it hardens instantly! Very handy to keep in the toolbox and fix sloppy threads. You can even start the screw, harden, then use the uv and the threads are now set.

    6 replies

    Get the bondic kit then lookup "LOCA GLUE" on eBay or Amazon keep the lamp and syringe refill the product in a dim room, afterwards seal the hole you make to refill with something black (nail poslish) to keep light out of your refill. Oh, sunlight cures this stuff fast too. Used LOCA for years used to call it glass glue by 3m also found in windshield repair kits and rearview mirror re-attach kits.

    i saw it on Amazon and wondered about it ... what projects did you find it useful for, what kind of bonding besides teeth :D I know the taste too.

    Any light mending really. I keep it in my tool box and tool drawer. I've used it to repair threads before. I've used it to temporarily "solder" wires together or even insulate them after soldering if shrink wrap or electrical tape doesnt't fit. My girlfriend works at an optometrist and they use it all the time for fixing glasses. It's better for building up something rather than gluing really. I dont find it all that sticky and even if it cures on your fingers it just falls off. If you need to stick 2 things together I would use superglue. For everything else, bondic.

    hmmm sounds like a perfect addition to Superman's tool belt! I bet it would work well on remodeling eyeglasses frames like when it cracks around the lens, or slips on the nose. Gonna get me some for creative solutions kit I always keep handy. Thanx

    Some of us are very familiar with that type of adhesive, because it has been in our mouths for years at a time (the adhesive used for braces is a very similar variety, cured by UV). IT TASTES TERRIBLE!

    I wish I could get my hands on that stuff my only gripe with bondic is that it is painfully weak unless you use a lot of the stuff. Also haven't tried tasting bondic so I can't say how similar the taste is lol.

    Another simple way to make a locknut is to make a sawcut half way through the side of the nut, about 25% from the end.

    Then hit the flat side of the nut with a hammer. This closes up the sawcut, and the top part of the thread acts as a locking device.

    I've been using ca glue for years, but I prefer the liquid version of ca. I tighten the nut, then apply a small drop of ca at the threads. There's also an alternative to locktite by Bison. It's cheaper and safe to use with plastic.

    2 replies

    Yeah i thought about locktite too. There's the blue and the red. Blue is alright if you need to loosen/tighten the nut again, but red will lock the thing for good.

    This is a useful guide for "safely" replacing a locknut if you don't have a new one to use. (i.e. you decide to fix your garden chairs on a Sunday). CA glue will do its job TEMPORARILY, it's not a permanent solution. I also use CA but only when health and safety is not an issue. I wouldn't use this method to secure my blender's blade, or my bike's brake caliper. Temporary solutions tend to fail catastrophically after a while.

    There's also an issue with the fumes. CA glue produces fumes that are toxic and will stain any plastic parts they come in contact with.

    There are lots of commercially available thread lockers. Some are fairly cheap, others are quite expensive. There's even thread locker for gas pipes and fire extinguishers. A commonly available thread locker where I live is the Bison metal lock. It costs 6,5 euros for a 10ml bottle and it's good for up to 250-300 M2.5 screws. It's not volatile to plastic, it will unfasten when you want to and it can handle temperatures up to 150 C. I use it in notebook repairs (nobody wants a wobbly screen or a creeking notebook after a month of use) and it does the job perfectly.

    Tools and materials have certain purposes. CA glue is a fast curing contact adhesive, not a plastic filament. If a locknut is needed, then a locknut should be used for a safe and long-lasting repair. You shouldn't replace a locknut with a common nut, the same way you shouldn't use a knife to unfasten a screw.

    Rubber cement is an interesting idea.

    I have successfully used plain old nail polish (raid wife/Gf's not used supply) in non-critical applications, as a Loctite replacement - also in comes in pretty colours :).

    Nail polish also works well to hold in wood screws that you don't want loosening (eg. IKEA stuff assembly) - would use "Clear" polish if results are potentially visible

    1 reply

    You can also get a perfect colour match.
    Titanium screw in titanium glasses, with colour matched nail polish preventing it coming undone.


    Another less expensive way is to distort the nut slightly using a ball peen hammer, Seat the ball of the hammer on the nut and with another hammer tap it just enough to distort a few threads. CAUTION: don't belt the hammers together to hard because they're hardened steel and will chip off like a bullet if hit to hard.

    2 replies

    Hammers don't break like that. Haven't you ever seen Mythbusters? They busted that myth TWICE.

    And yet it still happens. Very rare though. More common is mushroomed bits coming off a bolster or similar.

    E-6000 Adhesive works like a champ. Not too brittle and bonds well to metal.

    It will be awesome for drones :D

    I have weights that were always clainging and moving so I got some silicone and put a bead on the rod and between each weight and they are nice tight and best of all sillent.

    Thanks for the tip. Also in the past I have used a two-step method with silicone.( I work on older motors, All of which are Bow-Tie) Put a "skim/light coat of silicone on the piece you are going to bolt to. Alow to sit for an hour. Apply a "proper" amount of silicone (a bead) to the part. Wait about 45 minutes till it's almost hard at the surface. Install the part.....and tighten till half of the bead starts to spread out. Of course use a pattern of tightening that ensures an even draw of the part to the maiting surface, to keep even. Wait an hour. Torque it home. Finished.
    You have found a good part......but....if you are stuck again.....,Now you can work with that handy tube, you are likly to have...before extra gaskets kept on hand. Thanks again for the gasket tip....what engine were you working on....just for my "FYI"