Help Going MAD!

[Arct1k]

I wanted to make some links for my new clod crawler...

So I was told to get:

- 1/4" Ali tubing with .049 Wall thickness i,e, .15" ID
- 6/32 Threaded rod...

Well in Metric that should be:

- 3.81mm Inner Diameter
- 4.76mm Threaded rod

Well I have no idea what is going on because the 6/32 rod and the 6/32 tap measure 3.7mm wide and slide right through the rod! Bloody imperial measurements!

Now an M4 does thread ok but could take more...

What do I need 8/32 rod & tap?

This makes no sense to me...