Cast-in anchor nuts?

Just get some threaded rod and put a 90 degree bend in it, and cut to the length you want.

Why?
What is it you plan one anchoring, and why can you not plan for where it needs to be now?
A simple to install Red Head anchor would work.

Water, dirt, rusty threads, and freezing if in an unheated area; just a few things to think of with threads below grade. As mentioned, I'd go with some manner of J bolt if the exact locations are known at the time the concrete is placed, otherwise Red Head's after the concrete has cured.

I can see what the OP is getting at.....kind of like open floor plan and computer wires before wireless.....e.g. All wires under floor, easily accessible for hooking up whatever wherever. But the points on rust, crap in the threads, are well made. And maybe think about what it is you are going to bolt into place. A table saw? Jointer? Bigger machine?? Most anything except for industrial use is not going to be going UP but mostly sideways....and it doesn't take much to keep things from going sideways.....not like the continuous anchors for bottom plates that need to sink 8" into concrete in my area. So I would personally go for after pour additions. Ron

ront02769 said:

the points on rust, crap in the threads, are well made.

Click to expand...

They are shown to me made out of a Zinc/Aluminum/Copper alloy so they will not rust. They also sell screw in plastic caps to keep the crud out (or you could just put a short screw in it).

Grainger shows them about $205 for a box of 25, in 1/2-13 size.

I don't got a clue what the OP wants to use them for, have to assume he has some reason.