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Nutplates and screws

msmst25

Well Known Member
Am I doing something wrong? I feel like the screws into the nutplates requires much more torque than it should, and they aren't crossthreading. I'm using the K1100-06 nutplates on the elevator and they will go in, but it takes a lot of effort and I'm worried I am going to strip the Phillips heads on the screws.
I'd appreciate any advice
 
Nut plates and screws

When I install nut plates, I usually hold the nut plate With an older used cad plated screw. This usually helps with subsequent new screws where you don’t need so much torque. I find you will need to do this for sure if you use stainless steel screws as they seem to be a fraction larger in diameter.
 
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Nutplates have a locking thread, you can chuck a tap in a drill, dip in oil, and clean them out, or keep the locking feature, but definitely oil whatever screws you use, especially stainless steel screws.. and throw out your Phillips screwdrivers (or give them to somebody you don?t like) and replace them with JIS screwdrivers. The JIS fit Phillips heads so much better, I?m kinda mad that it took me 40 years to learn about them?
 
Nutplates

I have a jig. It clamps into the vise. Every nutplate gets checked. Screw and boelube. When the sacrificial screw gets worn, toss it. If the nutplate seems overly snug, I run a tap in a couple turns. The clamping feature is just a squeezed end. If you look, it's out of round. They don't get them all exactly the same.
 
Nutplates have a locking thread, you can chuck a tap in a drill, dip in oil, and clean them out, or keep the locking feature....

This comes up pretty frequently here, especially when new builders have their first experiences with nutplates, and statements like this Need to be made very carefully. Building an airplane is not like working on your house, or car, or boat, or bicycle - fasteners have locking features in aviation because it is very critical to not have fasteners come loose!

Yes, there absolutely are places in your RV build where running a tap through a nutplate to remove the locking feature is fine - interior trim and floor panels, for example. But when a ?newbie? reads someone?s statement to ?just run a. Tap through it?, they might do so on a critical part - like an elevator hinge retainer - and that would not be a good idea. It?s also not a great idea to have fairings come loose, so blanket statements can be dangerous.

Waxing and oiling screws, using good screwdrivers, and taking your time to do it right are the real answers to this problem.

Paul
 
This comes up pretty frequently here, especially when new builders have their first experiences with nutplates, and statements like this Need to be made very carefully. Building an airplane is not like working on your house, or car, or boat, or bicycle - fasteners have locking features in aviation because it is very critical to not have fasteners come loose!

Yes, there absolutely are places in your RV build where running a tap through a nutplate to remove the locking feature is fine - interior trim and floor panels, for example. But when a ?newbie? reads someone?s statement to ?just run a. Tap through it?, they might do so on a critical part - like an elevator hinge retainer - and that would not be a good idea. It?s also not a great idea to have fairings come loose, so blanket statements can be dangerous.

Waxing and oiling screws, using good screwdrivers, and taking your time to do it right are the real answers to this problem.

Paul

Point taken Paul, I was just explaining his options, and that the tightness is a feature built in, not a defect. Sometimes I like to ?soften? the locking feature, but you are right that I should be more careful with a blanket statement that someone could apply to all nutplates.
 
Thanks

Thanks for the input. I don't remember reading anything about the locking feature of the nutplates. I ordered some Boelube and now that I know that they are supposed to be reasonably tight, I don't have to worry that I'm using the wrong parts together.
 
Burnish the threads

It's the rough surface finish left by the phosphate coating. Run a hardened capscrew lubed with boelube in and out of the nutplate before installation. This smooths up the thread surface without removing metal as a tap would, thus preserving the self-locking feature. I do them in batches with my electric screwdriver. Of course this process can be used on nutplates already in place.
 
JIS is Japanese Industrial Standard. They are similar to phillips heads, but have a little different angle.
The preferred solution would be to not replace AN screws, but to replace the JIS screwdriver.
 
Thanks for the input. I don't remember reading anything about the locking feature of the nutplates. I ordered some Boelube and now that I know that they are supposed to be reasonably tight, I don't have to worry that I'm using the wrong parts together.

FWIW, every fastener in the airframe has some sort of locking feature. Nutplates have a bit of squeeze on them for a mechanical lock. Bolts are locked with nylock nuts or metal locking nuts or castellated nuts with a cotter pin. Rod ends have a jam nut. And safety wire on top of that in some cases and on hinge pins.
 
it's not unheard of to get a nutplate that won't thread. i clamp a screw in a vise and thread each lubed nutplate on it before i install. much easier than finding it bad after it's riveted in place.
 
it's not unheard of to get a nutplate that won't thread. i clamp a screw in a vise and thread each lubed nutplate on it before i install. much easier than finding it bad after it's riveted in place.

+1 whatever you do, check the nutplates before you rivet them on lol.
 
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