I just ordered a new timken Hub\Bearing (Part # SP450201) assembly for my 2001 Ranger 4x4, and according to its spec sheet it has M12 x 1.75 threads for the wheel studs, but when I shop around for new lug nuts everybody is trying to sell me nuts with a 1/2-20 threads. Whats the deal hear?
(I haven't used a caliper and pitch gauge on the existing studs yet because of in climate weather)

 

Your truck should be 1/2-20. I'm betting that spec sheet is either incorrect or the M12x1.75 is the size and pitch for the bolts that hold the hub to the spindle.

 

correct the studs are 1/2-20