OK, so looking at your model I see a couple of problems that make it difficult to get the holes lined up. The first is when you drew the circles for the holes, you dragged out their radii in some random direction instead of on axis. You should make it a practice to draw circles on axis. Here is a screen shot of the hole in your plate. The guidelines are parallel to the edges of the plate and centered on the hole. Notice the guides don’t pass through the vertices on the edges.
Here I’ve redrawn the circle dragging out on axis.
The same problem applies on your bolt with the added problem of the hole not being centered. The guidelines intersect at the center. The guide point marks the center of the circle. The blue axis line also runs through the center of the bolt.
Again, after correcting the hole:
After fixing those things up, it’s easy to move the bolt to align the circles. With the circles drawn exactly the same way in both parts you can use the vertices on the edges for inferencing or their centers or you can use inference points on the outside of the head (corners and midpoints of edges) to make the alignment.
You could edit the bolt component and modify the hex head to be the spacer and the plate.
7mmBolt_withPlate.skp (305.1 KB)
Thank you. I didn’t say that it was created without extensions. Just not that extension. Here’s a thing I did about year ago that shows how I go about modeling them. I suspect you’ll find that the one created the extension you used won’t fit a standard nut very well. At least not without a bunch of fettling. Maybe it’ll still work for your needs, though.