Nut Plate Attach

[Archer39J]

Something I've been wondering. If the rivets used to attach nut plates are only there to retain it when the covers are off, why are 2 required? I guess it could spin around with a single rivet, but even that seems like it would take some doing. Would that even be an issue if it did? The weight savings would be minuscule, especially because you're not removing skin material, so I'm just thinking about ease of construction and time saving here.

Also, what other methods have people used for attaching nut plates? I recall reading about some folks gluing them on with epoxy, but I don't know if I like that idea...

[Mark Goldberg]

In a few places over the years I have used some stainless ccc-32 pops to attach nutplates. But I would stick to the tried and proven. Or you might find your self having to cut a hole in something to get to the back side where a nutplate has come loose. Mark

[whee]

There is a single rivet version of the nut-plate but they are a PITA and I'd never ever use them. I had them on the wingtips of a previous plane and fought them every annual. The nut-plate bends very easily then the screw cross threads...

[Archer39J]

Both good points, I see why 2 rivets now

[Battson]

One other reason - nut plates have to withstand some shear force in many applications (like a wingtip), and you need to spread that over two rivets to avoid fatigue cracking and bending stress on a single rivet. This is also why aluminium pop rivets aren't always a good idea for attaching nut plates, it depends on the situation.

[Bcone1381]

When attaching those nut plates, I used a different rivet thats widely used by RV builders for nut plates. It called an NAS 1097 rivet instead of the standard AN426.

The NAS1097 is a countersunk rivet with a smaller head than the standard AN426. The advantage of using the NAS1097 rivet is the material that needs to be removed to have the rivet head sit flush to the skin is minimal.

nas1097ad3-2

[Sebastian]

I have used a single attachment on a few nut plates but use is only where space was a problem and where I could get to the nut plate with a finger if alignment was needed. So far the only place was on my baffle system where I can get to everything. Whee is right about them being easy to bend so I would never use them in the blind where I couldn't see or touch the plate while trying to insert a screw.

[Battson]

Be aware that mixing high stainless steel rivets with aluminium, in areas which are likely to get wet, will lead to dissimilar metal corrosion. It lifts your paint and fans out like little fractuals on the metal, it's generally undesirable.

[Flygirl1]

Archer39J, just remembered this post and thought you might be interested in taking a look at these rivitless nut plates--http://www.cherryaerospace.com/product/rnp

[Archer39J]

Flygirl1 Huh, those are pretty darn cool. Like a floating clinch nut... I like it! Looks like they only do #10 and up though, but I'm actually passing that around work now as we might have some applications there. Thanks

[Flygirl1]

Your welcome. Paul Dennington, 4 place plans #1257 originally posted about these. If your listening Paul--did you use them??

[Mark Moyle]

If .032" or thicker sheet.....I cut the counter sink..then AD flush rivet... if .025" thin or less... dimple both the sheet metal and the nut plate...then AD rivets..