Milling Aftermarket Wheel Hub Faces?

Man, I am just full of GRM questions this week...

I sent a couple emails to some wheel makers without a response. It's a simple question:

For a given model & size, do most aftermarket wheel manufacturers typically develop a single mold, then machine all the versions to differing offset specs? So, for example, are all of their 16x7 SooperMadTiteYo models at ET20, ET30, and ET40 from the same mold?

Seems to me that this would be the most economical way of doing things, but I have no real concept of wheel manufacturing, and maybe too much material is wasted on a rim that's milled to only ET20 vs. a deeper ET40?

Thanks...

Honestly most aftermarket wheel manufacturers typically don't offer a huge range of offsets. If there is a et40mm it likely has a different mold than an et20. Also many times if they offer different offsets, they are two (or three) piece wheels and they move the centre section relative to the rim shell so they only have to cast one centre section.

I think it would depend on the wheel itself. I have seen some wheels cast with a thick hub and then machined to size. The limiting factor would be is how deep the pocket for the lug nuts is machined or how thick is the hub at that point will determine if the wheel can be machined to change the offset. I would not want it to be thinner then say 25-30 MM right at the hole for the mounting stud/wheel bolt. Since most holes are tapered the hub will actually be thicker, more like 50-70 MM.

They will do that to a certain extent, but if there is more than a half inch or so difference, they will have a different mold. I was part of a group buy on some Rota RBs. Standard option has a 25mm spacing and we wanted 15 spacing. It is obvious by looking at them that there is extra material on the back of the mounting face. So much so, that it makes putting the lug nuts on a real pain because they are cut so deep inside the hub.