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CA works for #2-56. For #4-40 I tend to use a backer into paper. Where CK used steel, I used brass. Worked spectacularly, but I must say: the T-nuts, above, look pretty slick. I'd get some of those in #4-40 to try out...


I don't have 4-40's yet, 2-56 & 6-32. I have used the 2-56 on 3" body tube and the 6-32's on 5" body tube.

My original design was 4-40 used on 4" body tube. After some experimentation the 4-40's may not be necessary. Would someone like to try some 2-56's on a 4" build? Please PM if interested.

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Other places to get them are Grainger (perhaps there's one near you -- save on shipping), and

Make sure they aren't too long. if you have a digital caliper, that is great for measuring tube thickness. You want them to protrude through the tube a little bit, but not too much. If they protrude too much, you risk getting your chute/harness hung up on them.

1/4" or 5/16" is usually plenty.