Originally Posted by Ex Pres

I don't know if there are any markings on the hub to tell you, but having a set of thread pitch gauges can be helpful in many cases, as well as a digital caliper. And these aren't expensive, like $10-$15 for the calipers and probably less for a set of the thread gauges (mine were included in a tap and die set). I use both of these tools extensively on my bikes.