Rivet questions

[rdsikich1]

I cant find what kind of rivets to use, all the book says is Ms20426-3 but that doesnt tell me the diameter, or if they ar AD hard rivets or soft, could someone help any comments wold be appreciated, and what are the 6-32 nut plates??

[Chewie]

Are you looking at the book or the plans? It seems part of that rivet designation is missing, e.g. MS20426AD3-3.

[LukeS]

The -3 is the diameter in 32nds of an inch. If you look at the individual drawings the rivet spec will show AD when necessary.
These are nutplates---> http://www.aircraftspruce.com/search...PLATES&x=0&y=0
6-32 is the thread size.
These are pretty basic questions, which indicate you will learn a lot while building your project. One resource which has been very valuable to me are Eric Newton's build manuals. They take a lot of the mystery out of the build sequence and will get you headed in the right direction. http://mybearhawk.com/buildermanual.html
Otherwise just keep the questions coming and there are enough folks here to answer them.

[rdsikich1]

thanks but yeah i know thats my problem chewie im looking at the drawings and they only say ms20470-4 for example then theres side notes that say they need to be AD unless otherwise noted which is understandable, i just assumed the drawing must be indicating the -4 as the diameter size and leaving out the length?? not sure i guesse i didnt word my question specifically enough, and yes i have all his manuals but he doesnt give you details like that, but thanks i appreciate the help

[bestbearhawk1231]

The MS20470 stands for the head style in this case a dome head rivet (MS20426 is a flush head) they also go by the old AN number, basically change the MS to an AN and drop the 20
AD is the alloy that the rivet is made of, in this case it is a hard rivet...the other common alloy is the A which is soft and only used in non structural areas. In our case the fuel tanks are the only place they are called for and they are used to hold things in place until they are welded over (A rivets can be welded, ADs cannot)
The first number after the A or AD is the diameter in 32nds, the last number is length in 16ths. The lengths are not given since it is left up to the builder, I would suggest getting a rivet length gauge to help train your eye. I would also get a set of go/no go gauges to check your driven rivets to make sure they are acceptable.

Nutplates come in several varieties...metal locking, fiber locking, floating/stationary, standard size/ minis, corners, one legged...and then there are the sizes... -3s are 10-32 while the rest match the AN sizes

If you have not yet picked up a copy of the 83.13 it will have all of this info in it. I also keep a small handbook in my shop for a quick reference, they are pretty cheap. Jeppeson makes a nice training manual for sheetmetal, basically they take the info out of the 83.13 and make it a little less "dry".

Hope this helps a bit.

[bestbearhawk1231]

Also, the Wicks and Aircraft Spruce and Specialties have a lot of reference charts in them that helps out. Good luck with your project and don't be afraid to ask.

[N3UW]

For the nutplates you typically use #6 countersunk screws. K1000-06 nutplates can be used as eric points out in his manual. Also for a few more $$ you can but the K1100-06 nut plates that are already countersunk. They do make a cleaner install. Van's Aircraft has them a lot cheaper than Spruce. Here is the link. http://www.vansaircraft.com/cgi-bin/...product=nplate

[Chewie]

Joe - What is 83.13? Do you mean 43.13?
John - have you tried using the shallow-head rivets for standard nutplates? I'm curious what people think of these; they have a shallower head that allows flush riveting in .025-ish material without having to c-sink or dimple the nutplate. At least that's how I understand it. NAS1097.
rdsikich1 - I have Patrol plans but here's an example that's close to what you describe. I would say you're correct, for "MS20470-4" they are most likely AD (2117T alloy) and the 4 signifies the diameter, not the length. My plans hardly show any length call-outs. Perhaps Bob's notation has changed along the way; on mine the AD and diameter designators are specified almost every time with no dashes.

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[bestbearhawk1231]

I was off a bit on my numbers...

The reduced head NAS1097s work pretty well for holding nutplates.

[rdsikich1]

yes thanks for all your help guys, Greatly appreciated

[mswain]

I've used the 1097 in a few places. They are handy when you need them.

As far as the MS20426AD3 lengths, on the wings I've primarily used 3.5, 4, and a few 5 lengths. For MS20426AD4 I've used 4 & 5 with a few places requiring 6.

I keep some real long in each size and cut them to length with rivet cutters if I come across the need for an oddball length.

[N3UW]

Hey Chewie. I did use the small head or "oops" rivets for nut plates on access panels and other non structural applications. I have not used them in 0.025 but have used them in 0.032. As far as the tank access panel, I did use standard rivets and dimpled the skins and the nut plates. The oops rivets ups have probably also been fine there since. I just started dimpling before I thought about it.

Joe - What is 83.13? Do you mean 43.13?
John - have you tried using the shallow-head rivets for standard nutplates? I'm curious what people think of these; they have a shallower head that allows flush riveting in .025-ish material without having to c-sink or dimple the nutplate. At least that's how I understand it. NAS1097.
rdsikich1 - I have Patrol plans but here's an example that's close to what you describe. I would say you're correct, for "MS20470-4" they are most likely AD (2117T alloy) and the 4 signifies the diameter, not the length. My plans hardly show any length call-outs. Perhaps Bob's notation has changed along the way; on mine the AD and diameter designators are specified almost every time with no dashes.

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