[tyconnell]

Greetings,

RV-9 empennage, fiberglass attach points: I?ve drilled / dimpled the skins for the CS4-4 rivets per the plans. Now I?m rethinking that. I *think* a #6 screw is a slightly larger hole. Is it possible at this point to convert these CS4-4 holes so I can attach the fiberglass tips with screws instead?

Not a big deal if not, I?ll just continue with what I have.

 

[az_gila]

A good printable reference chart here -

https://littlemachineshop.com/images/gallery/PDF/TapDrillSizes.pdf

The #6 screw clearance hole is only .019" larger diameter.

Drill the existing holes out with a #27 drill and re-dimple and countersink with the #6 sized tools.

 

[sbal0906]

Would you need to use platenuts to screw into?

 

[DaveO]

You need something to screw in to. I would use nutplates.

 

[tyconnell]

A good printable reference chart here ...

That?s a great reference, thanks!

And to answer the other question, yes platenuts.