Adjustable leveling wedge (jack wedge)

I made this leveling wedge as a tool in my workshop / garage (I was welding a large metal frame and needed to level it). I made 2 variants:
1] with flat bottom/top
2] with a bottom "tripod" and top "sphere" to be stable on non-flat surface and support a plane.
3 of these should help you to level any plane.

The only size actually available is H 4 x W 4 x L 7 cm and M6 threaded rod + M6 nut. I provided parametric Inventor model, so feel free to modify or let me know and I add the size you need to this collection.

I designed it to use the M6 nut and threaded rod (parametric). The nut is locked inside on the one side. I recommend nylon insert lock nut to prevent spinning of the rod on wrong side. The other side should be accompanied with a washer and wing nut.