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Nordlock vs Safety Wire

erich weaver

Well Known Member
Safety wiring my Whirlwind 200RV prop is a pain and I dread it. Is there any reason why Nordlock washers couldn’t be substituted? The promotional YouTube videos indicate they perform as good or better than safety wire in vibration tests and would certainly save time and aggravation.

Erich
 
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I view them as two different things: The Nordloc washers prevent the bolt from making minor movement that will allow it to loose it's elongation. The safety wire keeps it from turning if it were to come loose. Safety wire is not going to do much to prevent very minor movement, so the integrety of the fastener relies on the bolt elongation. The safety wire is more there as a "Safety" Back-up.
I would think the best practice is to use a nordloc washer and then safety wire it.

What is it that you are finding difficult with the safety wire? If you watch a few You Tube videos you will pick up some tricks that make it quite simple and fun.
 
Vans' answer to this question, at least for the RV-12, is in a post currently a few lines down titled "safety wire".
 
0.041 safety wire on my prop bolts. Positive thinking may help, think: "maintenance is fun". :)
 
Sensenich specifies/supplies Nord-lock washers for their propeller installation on my carbon fiber GA prop, including certified versions of these props.
 
Whirlwind

Their GA200L FP prop/spinner kit use nordlock. I also used them on brake calipers as well.
 
We have been seeing the use of nordlocks on props, brake calipers, etc for quite a while now, and have been using them ourselves on brake calipers regularly. Saves time and seems to be very secure.

Vic
 
Nordlock

We have been seeing the use of nordlocks on props, brake calipers, etc for quite a while now, and have been using them ourselves on brake calipers regularly. Saves time and seems to be very secure.

Vic
I have not yet tested them, and they look great. Where's the best place to buy them? The few places I've seen are kind of expensive...
 
We have been seeing the use of nordlocks on props, brake calipers, etc for quite a while now, and have been using them ourselves on brake calipers regularly. Saves time and seems to be very secure.

Vic

Have you tried them on the wheel pant axle bolt? That would speed up wheel pant R&R .... maybe I need to buy a few Nordlocks and give them a try.

Paul
 
A side question - how many times can Nordlocks be reused, if at all? The manufacturer's website says they can as long as some resistance is felt when removing the associated fastener. OTOH, Matco recommends replacing them after one use on their brake calipers.

??

Dave
 
We reuse Nordlocks pretty routinely on the vibe tables at work. The locking design is implemented by the angle of the teeth, so unless you severely mangle the teeth, they'll still provide a locking function. They deform slightly during install/uninstall, but not enough to really affect how they work.
 
Safety wiring my Whirlwind 200RV prop is a pain and I dread it. Is there any reason why Nordlock washers couldn’t be substituted? The promotional YouTube videos indicate they perform as good or better than safety wire in vibration tests and would certainly save time and aggravation.

Erich

....I agree about it being a real pain! Especially with this particular propeller, as it appears the
relief cuts milled in the hub, where the nuts go, aren't deep enough to allow clearance for the
safety wire. We have installed many of these, and I now do this simple modification to the
nuts by machining a clearance groove a bit larger than the safety wire (see pics) prior to the
first installation. This can save you many hours of frustration, and your finish job will be neater
and cleaner, I promise. Thanks, Allan--:D
.

.
 
Wheel pant axle bolt

Have you tried them on the wheel pant axle bolt? That would speed up wheel pant R&R .... maybe I need to buy a few Nordlocks and give them a try.

Paul
I put Nordlocks on the wheel pant axle bolts last time around. I can lie on my side and safety wire the brake caliper bolts rather easily, the Hartzell prop bolts are a minor aggravation, but the wheel pant axle bolts have gotten ever more challenging for my knees and back.
 
Nord lock

YES! On brakes and wheel pant. Worth every penny. I hate saftey wiring and my tech counselor told me to go to them. Been flying with them for several years now and it makes it so much easier to really inspect and replace as necessary my brakes. Now if I could just find a really easy quick way to pull the bottom cowl to just look more often.
 
What is Hartzell's position on nordocks?

There aren;t any washers involved in installing. Hartzell C/S prop - it doesn;t early have “bolts” exactly - more of a nut pinned on a threaded rod with a split pin. I don’t know where you’d put the Nordlock in this installation.
 
There aren;t any washers involved in installing. Hartzell C/S prop - it doesn;t early have “bolts” exactly - more of a nut pinned on a threaded rod with a split pin. I don’t know where you’d put the Nordlock in this installation.

...You have to un-pin the nuts and bolts from hub, then
reassemble them with the washers in place and re-pin.
I did a couple, seemed to work OK Thanks, Allan
 
Safety wiring my Whirlwind 200RV prop is a pain and I dread it. Is there any reason why Nordlock washers couldn’t be substituted?
Erich

Does your Whirlwind prop have an aluminum hub? If so, the Nordlock washers could work very well.

I don't think Nordlock washers would work at all with a one piece wood or composite prop since the hubs on these props can change with time and humidity (Isn't Catto and Hertzler now recommending belleville washer with their props?).
 
Dunno, but their position on safety wire is "option", they don't recommend it, but say it is ok for the airframe manufacturer to add the safety wire.

That’s correct. I know, because my DAR made me look it up. Their manual, wrt safety wire, says, ‘Follow airframe manufacturer’s guidance’.
 
That’s correct. I know, because my DAR made me look it up. Their manual, wrt safety wire, says, ‘Follow airframe manufacturer’s guidance’.

Maybe true, but I have worked with numerous Hartzell engineers doing propeller flight testing and I have never seen a single one of them take the option of not installing safety wire. Even when the prop was only to be installed for a couple of hours of testing.
 
...You have to un-pin the nuts and bolts from hub, then
reassemble them with the washers in place and re-pin.
I did a couple, seemed to work OK Thanks, Allan

Yeah....but that is going to leave you a couple threads shorter on engagement on the prop flange bushings. I have no idea if that is OK or not - would want to see whomever designed the interface bless that configuration. There’s probably tons of margin - but the margin belongs to the designer, not the guy in the field!
 
The whirlwind prop also uses pinned nuts on studs, so the same concern regarding the degree of engagement would apply if Nordlocks were added. A call in to Whirlwind may be in my future.

Erich
 
I would think the little wedges of the washer would eventually screw up the flat matting surfaces.............
 
Some of us on Legacy RV-12's are now using Nord-Locs under the 4 screws that hold the Gascolator bowl in place, in lieu of safety wire, during Inspections
 
Some of us on Legacy RV-12's are now using Nord-Locs under the 4 screws that hold the Gascolator bowl in place, in lieu of safety wire, during Inspections
Ditto on my 2007 RV7. I check tightness every couple of hours and there's no movement.
 
Yeah....but that is going to leave you a couple threads shorter on engagement on the prop flange bushings. I have no idea if that is OK or not - would want to see whomever designed the interface bless that configuration. There’s probably tons of margin - but the margin belongs to the designer, not the guy in the field!

... I still like the little nut modification I posted in this thread. It really takes the hassle out of doing the tie-wire job, and doesn't change anything dimensionally. Thanks, Allan --:D
 
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What about the oil sump finger filter screen? That is the most difficult safety wire install for me. That would save me an hour on every condition inspection. Could you use it with crush washer?
 
What about the oil sump finger filter screen? That is the most difficult safety wire install for me. That would save me an hour on every condition inspection. Could you use it with crush washer?

That is a great idea! Hardest location to install safety wire for me, as well. I’ll have to look into sizes available.:)
 
What about the oil sump finger filter screen? That is the most difficult safety wire install for me. That would save me an hour on every condition inspection.

Thread drift but that’s a big reason I got a DMC Safe-T-Cable system.
 
What about the oil sump finger filter screen? That is the most difficult safety wire install for me. That would save me an hour on every condition inspection. Could you use it with crush washer?

No, Nordloc washers will not act as a gasket, and they require fairly high torque to set them relative to the torque used on a crush washer.
 
I sent Whirlwind an email this morning asking for their input on the use of Nordlocks with their props. Jay Williams at Whirwind got back to me saying they do not recommend it. No further explanation which was disappointing, but that was their answer. Hmmm.

Erich
 
Nord Lock - It's Gitchy

How long has safety wire been around? I don't know, but I can say that I've cut .032" safety wire in 2014 that was installed in 1956.

Safety wire is cheap and it's got a really really long shelf life and it fits a lot of things.
No safety wire I've ever installed has failed - never.
Safety wire comes in stainless, monel, and inconnel (at least)
I don't really need to "check the torque" of something I've saftied.
Safetying a Hartzell CS prop with .041" takes 10 minutes tops.
You ever try to break .041" by turning the bolt?
If I drop a can of safety wire on the ground, I can easily find it within a couple of minutes.
.041" safety wire will go through the tip of your thumb with no problem (lets see a Nord Lock do that)
Safety Cable is an option to safety wire and it's that much quicker.

Most of all Safety Wire Just Looks Cool (when it's done right)
 
I would think the little wedges of the washer would eventually screw up the flat matting surfaces.............

The wedges on the washer don't contact the mating surface on the engine or prop. The washers are used in pairs, with the wedges facing each other. That leaves the flat sides exposed on the outside, and it's those flat surfaces that contact your engine/prop/bold head.
 
The wedges on the washer don't contact the mating surface on the engine or prop. The washers are used in pairs, with the wedges facing each other. That leaves the flat sides exposed on the outside, and it's those flat surfaces that contact your engine/prop/bold head.
The outside seems to have ridges. I've never used one so no idea if they "damage" the surface that they are touching, I would guess so.

nord-lock_technology_wedge-locking.jpg

https://www.nord-lock.com/nord-lock/technology/
 
Thread drift. See post #1. Let me know when there is a YouTube video of someone safety wiring a WW 200RV prop in 10 minutes.

Erich

Sorry, I thought the title of the thread was Nordlock vs. Safety Wire. But, if you find safety wire too difficult or time consuming and WW doesn't recommend nordlock, you should probably look into safety cable as another option or you can pay someone $20. https://www.dmctools.com/products/safe-t-cable/
 
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But, if you find safety wire too difficult or time consuming and WW doesn't recommend nordlock, you should probably look into safety cable as another option or you can pay someone $20. https://www.dmctools.com/products/safe-t-cable/

Nice tool. Better be at $560 plus the cost of the cables.

If someone is willing to safety wire my whirlwind prop for $20 I’m all ears. Apparently they would be willing to work for less than minimum wage.

Erich
 
The outside seems to have ridges. I've never used one so no idea if they "damage" the surface that they are touching, I would guess so.
Hey, good catch. I am familiar with the technology but haven't used them before so i've never held a set. I thought the person was asking about the "large" wedges that made up the locking mechanism, I didn't know they had tiny ones on the outsides too. It looks like they are angled to slide nicely while tightening the fastener, but to bind in if you try to undo them. That suggests you wouldn't want to use them in a location where regular removal for maintenance is needed... It looks like you'd remove a little material each time you undid them.

Oddly enough, in the photo at the top of that page, angle alpha looks to be less than angle beta...
 
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