[tdonsker]

Hello all, this is my first post so please be kind (chair)

I'm a furniture designer with an architecture background (meaning I cheated my way through physics so I could design my silly building longer). But, I am willing to do some math now!

Heres the deal:

I'm drilling a 1/4" hole in 16gauge cold rolled steel 1"x2" tubing. In the past I would slip a female threaded fastener (with a washer for added area) through the hole and then attach the male and call it a day. However, I would prefer not to do this. Instead, I'd like the female permanently attached (welded?) so that I could remove the male to make manufacturing easier.

So my question:
I would like to tap the tubing, but I don't feel comfortable with the very minuscule wall thickness. I have tested it in an amateur fashion by mounting a piece of 2x4 to the bottom and jumping on it (around 180lb) and it did not budge. But, to sleep better, can anyone calculate or tell me how to calculate the max pull out strength before failure? The male threaded end is AISI 316 material (stainless steel), and as mentioned above the female is .0598". Would switching to 14 Ga. (.0747") add significantly more strength? If so how much? I assume that the max load on this will reach 200lb, with a typical load around 100-150lb.

Thank you!

[tdonsker]

I'm considering using rivet nuts . I also read about the flow drill which is interesting, but my drill press is .75hp and it needs 1.3 for my application.