Re: steel thickness for home made trailer
If you are using HSS (hollow structural section), then you will have a limited, but acceptable wall thickness.
For example, a 2"x2" square HSS will come in 1/8", 3/16" or 1/4" thickness.
Like Bond-O suggested, the 3/16" will be your better choice, for strength and ease of use (welding, drilling, etc).
Tubing comes in more sizes.
2"x2" square tubing can be found from 16 gauge (.065") up to 7 gauge (.180"), and also 1/4" (.250W).
The size of HSS or tubing for the tongue should match your intended hitch mount, which comes in a variety of widths and ball sizes.
Don't skimp on this part, a strong tongue that runs front to back makes for a strong reliable trailer.
As Bond-O mentioned, 1/8" thickness for tubing is acceptable. Just don't ask too much of the structure by limiting the amount of gussets, cross members, etc.
Good luck!
