Aluminum frame motherboard standoffs?

[vr.]

I'm looking for some help identifying/locating the motherboard attachments these type of aluminum frame "cases" use:

https://www.amazon.com/dp/B0B8H2VLTY/

Looks like it might be a flat stock with 3 holes?
A screw into one end and the other end, a hex piece eludes me. Is it male on one end, female on the other like the typical brass varieties? What thread might they use?

I'm also interested in other ideas for attaching a motherboard to these aluminum sticks. I could do zip ties I suppose

Edit: I know I linked an atx version. The photos were more crisp than the mitx version I looked at.

 

[Nobu]

The frame is extruded metal (usually aluminum). T-nuts slot into the extrusions, and then you use a male-female standoff with the correct threads for the nuts to attach the motherboard. I'm not sure how the frame is assembled, I guess it depends, but you could probably drill through the side of an extrusion and use sheetmetal screws to screw into the center of an extrusion if it's the right size (or machine screws if you have a tap).

The othet two holes in the t-nut are probably for set screws, to keep the nuts from moving. They probably aren't strictly required, but it will keep the mb from moving if your t-nuts have a lot of free play. You want something like this, although this one only has two, and probably won't be the correct size either: https://a.co/d/eIMlgGt

 

[Nobu]

Alternatively, you could drill a small hole through the extrusion, tap it, and put a set screw to hold the t-nut in place. That would be a bit weaker than having the screw in the harder t-nut, though.

 

[Nobu]

Oh, here's one with three: 3287 Double Slide-in T-Nut, https://a.co/d/gtpNtXE

 

[vr.]

Ok you've got me headed in the right direction, I think.

There looks to be many varieties of 90 degree connections...
https://www.amazon.com/gp/aw/d/B08D6T9CGN
and single hole slotted nuts. I will keep following their Amazon breadcrumbs to find a match.