:thumb: Belg is correct !!! P2k, for example, has brass wheels and plastic axles and as a result, you'll find one now and then that has flaws. On the other hand, IM wheels are brass and so is the axle with a plastic collar around one end of the axle. You won't find too many of these that are flawed.
FYI, about 7 years ago, MR. did a survey and IM wheelsets won top honors, hands down, over all other brass wheelsets. They cost more but if you can afford them, they're worth the extra bucks. They retail for $78 if you buy 100 at a time. You can shop around and find them for $50 to $55 for 100.
Dick
Texas chief