We were tipped off to an older video by [AgentJayZ] which demonstrates the proper use of lockwire also known as ‘safety wire.’ In high vibration operations like jet engines, street racers, machine guns, and that rickety old wheelchair you want to turn into a drift trike, a loose bolt can spell disaster. Nylon fails under heat and mechanical lock washers rely on friction which has its limits. Safety wire holds up under heat and resists loosening as long as the wire is intact.
Many of our readers will already be familiar with lockwire since it is hardly a cutting-edge technology — unless you are talking about the cut ends of lockwire which [AgentJayZ] warns will slice up your fingers if you aren’t mindful. Some of us Jacks-or-Jills-of-all-trades, with knowledge an inch deep and a mile wide, may not realize all there is to lockwire. In the first eight minutes, we’ll bet that you’ve gotten at least two inches deep into this subject.
[Editor’s Note: an inch is exactly 25.4 mm, if the previous metaphors get lost in translation. A mile is something like 2,933.333 Assyrian cubits. Way bigger than an inch, anyway.]
Now, those pesky loose bolts which cost us time and sighs have a clear solution. For the old-hands, you can brush up on lockwire by watching the rest of video after the break.
Thank you [Keith Olson] for the tip, and we’ll be keeping an eye on [AgentJayZ] who, to date, has published over 450 videos about jet engines.
If safety isn’t your highest priority, consider this jet engine on a bicycle or marvel at the intricacies of a printable jet engine.
29 thoughts on “Everything Worth Knowing About Lockwire”
Hardly a street racer, the Flathead Ford engine in my old truck has its flywheel secured to the crankshaft by 4 safety wire bolts.
Lockwire, cotter pins, etc.
That’s 6″ deep and 3 miles wide than you very much. :-P
Does the metaphor change if it’s still a two-dimensional shape and the volume remains zero?
“Powder River, 1 mile wide and a half inch deep, too far to swim, and too thin to drink!”
-old cowboy saying
That’s a pretty dumb saying. Regardless of how wide the river is, it’s depth is the problem. You can neither drink it nor swim it due to depth, and it could be any width, and nothing would change. Also, if it was half inch deep, you could probably figure out a way to drink it.
I just hope that anyone endeavoring to use it remembers to wrap it around the fastener the correct direction.
I had to laugh as I saw a few that were wrapped to the wrong side, encouraging the nut to loosen, rather than preventing it!
If anyone is interested in practicing safety wiring skills, poking a few holes in a board and putting a few retention wire ready nuts and bolts through it allows you to easily practice on a fixture at your bench, rather than bend over under the hood of your car, truck, motorcycle, or jet.
This is one of the training and practice fixtures that we used while I was in the Air Force, rather than watching the new guy/gal try repeatedly to secure a hydraulic cylinder or wheel lock ring.
(It also makes the aircrew far less uncomfortable, when the final check is that, rather than one of fourteen, as the new tech is struggling to get it up to their trainer’s standards!)
I’m not saying I saw the wrong-way-’round wires in the video, just in other’s practice work, or pictures of their cars on the internet.
Also, I haven’t been able to listen to the video, and the fixture he is using only has the three bolts, so I don’t know if they mentioned guidelines I was taught regarding not tying more than three bolts together. It makes for far more work to do, if you have to re-work any of the ties, and also gives more chance to have a small mistake in one point cause you to re-wire the whole thing.
Tying a dozen bolts together, only to screw up and put a kink in the wire on the 11th would be a huge annoyance…
It would also require handling a really long wire at the beginning of the run.
He mentions that a pro might be able to do 6 in a row, but about 4 is probably the most you’d want to do because of the work-hardening of the wire.
Fix it on the squawk sheet…
Aircrew: Right landing gear looks like it was wired by drunk trainees
Maintenance: Trainees fed black coffee.
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For the past week I’ve been watching backlog of his videos, they are awesome. Highly recommended.
Weird. I just started watching his videos a few days ago because this very one was recommended.
Thank you so much for the conversions! My heart has warm cockles from that slight dig at the people who act all uppity about speaking 3 languages, but throw fits if they have to convert a measurement. LONG LIVE THE ASSYRIAN CUBIT!
No coincidence, it just means you made “the list”.
ok, and how does the next maintenance technician remove all those lock wires ? Is there an easy method for that, or does it take forever too ?
Small nippers from what I’ve seen, or flush cuts right at the side of the bolt.
and when they’re working on aviation stuff, those little snippets must be collected somehow .. ?
Yep. We all had little bags of the crap by the end of the job.
What would the criteria be to use lockwire over an old fashioned safety lock pin ?
No discrete positions and you can wire the head of a socket head cap screw in a blind hole.
Watching him yank the wire tight would have had our load barn guys screaming bloody murder.
Bolts, schmolts….try safety-wiring rigging turnbuckles just once. The next time you see a picture of a WWI biplane, think of the poor riggers having to keep all that stuff adjusted and wired tight.
Seems a bit laborious and dated, did they not invent something better yet?
In a word, no, frequently the thing you’ve just wired cannot be seen without dismantling something else, it’s totally reliable if done properly which is why the people that teach it are such perfectionists.
I’m not saying this isn’t sturdy and reliable, but if I see his demonstration and the time it takes, then see that engine with hundred of bolts, then think of the many commercial endeavors then you think there MUST be a quicker more economically sound way..
I guess this is why that JSF is so damn expensive eh :)
Nord-Lock washers are a possible substitute. I doubt that any industry that requires reliable assembly practices (aviation, for example) will make the switch. And I’m rather fine with that.
this has been sitting in my “recommended” videos for a good month now, I seen it years ago, now its hunting me here?
Maybe I’m not understanding, but what about the other end of a nut-bolt combination, the nut? I can see that if you have a bolt in a tapped hole, using lock-wire or the cable ties, as in the video, would keep them secure, but what about if you have a through-hole bolt that you want to keep torqued…how do you lock (-wire) in place the nut side? For example, using slotted nuts and cotter pins could provide a little “play” before the pin engages the nut. Any suggestions?
With lockwire holding a bolt, even if the nut vibrates off, the wires are to hold the bolt in its place until the
pilot hears/feels the extra vibration and lands the plane to find out what caused the new vibration.
Also, the bolt may be threaded into something other than a nut, such as a flywheel or holding a propeller onto the crankshaft.
A bolt, being much larger than its nut, is likely to cause a lot more FOD.
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