Wingtip Screws

[tacaruth]

The wingtips on my 7A are attached with stainless steel #4 screws. I just removed one of the wingtips to add an EFIS magnetometer. About 25% of the screw heads were stripped during removal (some may have been damaged during installation). Are there any better fasteners for this use?

Thanks in advance.

Tom, RV-7A N175TJ Flying

[67MK Larry]

use a new phillips head every time and avoid the tendency to strip. also I start and finish with manual driver.

[RV7Guy]

I have no idea who came up with idea of using 4-40's on the wing tips. There are no other 4-40's on the entire airframe, (7's anyway). They are way too small.

I originally used them on my plane during the initial build. When removing the tips for painting I stripped several, phillips head. I had the hardware and replaced them with 1000-6 nut plates. With the help of a friend we did the entire task in 2 hours. Now much easier to remove the tips.

If you are considering using the 4-40's do yourself a favor and go with the larger hardware. You won't be disappointed.

[9GT]

Use the 100* Torx SS from these guys. They were made specifically for aviation purposes.
http://www.microfasteners.com/catalo...Category=FCMXS

[apkp777]

SS screws strip really easily, especially when you can't push really hard (like the wingtips). "back in the day" we used to use Clover Valve Lapping compound on our bits to give them some extra traction. It worked surprisingly well. Some 400 grit will work great. http://www.cylinderheadsupply.com/clovercompound.html

[Snowflake]

If you're using a phillips head screw, it will definitely strip. The only solution to avoid it is to go to a screw with a proper head that won't strip. The Torx screws from Microfasteners are an excellent alternative. I plan to upgrade to non-phillips fasteners every time I remove one on my -6, but I haven't decided between torx and robertson (square). I have to look around a bit and see what's available.

[Greg Arehart]

I agree that the 4-40 phillips screws are not very good. I would use #6 screws if I had it to do over again. I'm going to look into the torx or square drive ones since I don't want to change out the nutplates on the painted wings.

greg

[Bob Axsom]

I have many sets of wingtips that I switch. I went with #8 hardware from the beginning and there have been no problems.

Bob Axsom

[rvmills]

Originally Posted by Bob Axsom

I have many sets of wingtips that I switch. I went with #8 hardware from the beginning and there have been no problems.

Bob Axsom

I don't have as many sets of tips as Bob (workin' on it ), but I too have #8 screws and nutplates and they've been easy to work with. Feels like too doggone many of them sometimes! And they are the same as the ones on my cowl and wing root fairings, so it makes for a little commonality of parts benefit (FWIW).

Cheers,
Bob

[Andy_RR]

How often do people need to pull their wingtip?

I'm planning on pulled rivets, but I'm just wondering...