How do you determine which size lugs are needed to mount the wheels on a rear axle? The length is easy to determine, the problem is the knurled portion of the stud. Summit, for example, has 1/2 inch lugs with a .594 knurl, a .615 knurl and a .625 knurl. Obviously, the knurled area must be larger than the hole in the axle flange. The question is how to determine how much larger does it need to be to properly fit.

some disagree with my thoughts, but i try to shoot for a .010-.015 difference in the hole to knurl size. i also use a press instead of a BFH to install the studs with a properly supported flange to prevent the flange from bending. if replacing studs with the same diameter knurl, it's possible to use a nut and washers to draw the stud in, but i do not care for that method because of the very good possibility of stretching the stud threads. just me. your results may vary.