Flange nuts (also known as weld nuts) can be used to help secure your railbuttons to your rocket.
They come in several different sizes.
8-32 threads for 1010 Railbuttons
When installing the flange nuts inside your rocket, depending on the thickness of the body tube, a portion of hte flange nut may protrude.
Spacers are available to place over the protrusion when mounting the railbutton on thinner body tubes.(Below)
Available in a package of 4 for $1.00
or a package of 10 for $2.25