The only semi truck lugs that were left hand were for the old style nut located wheels. They used a inner nut on duals that was threaded on the outside as well, and a normal looking nut on the outside wheel, left threaded on the left side of the truck. The inner nut secured the inner wheel, then you put on the outer wheel, and the normal looking nut secured the outer wheel. I've had the studs break off and actually used the inner and outer nuts in that spot so you couldn't tell the stud was broken! The inner nut was a square head while the outer nut was a normal hex head. Modern wheels on semi's are are hub piloted, so you only use one nut, the wheel faces sit on one another where the old two piece nut wheels rode on the cones on the nuts.