semi wheels

i understand that a semi wheel is 22.5 and that a low pro 22" tire is not the .5 and not recommended for mounting on a 22.5. What are they milling down on the 22" semi wheel to run 22" tires. Are they actually milling them down or are they just running 22" tires. Many other shops will NOT tell me shit. SO i am tryin to figure this out. JC

Its very difficult to explain to you.You almost need a wheel in hand to see.But they mill the bead wheel down so a standard tire will seat into place.You only mill one side of the wheel and its the face side of the wheel.And in some applications they mill the face of the wheel down so they arent as wide.
To make them run closer togther.