Sammyboy, you don't need to round unless the length is .5 or greater. those lengths are all less than .5 why round up? if your measurements were accurate, you shouldn't need to round up for those lengths.

nowheels, nipples, regardless of length, have the same number of threads.

Pompiere, how can a spoke puncture a tube if it's being laced to a rim that's double walled and has rim tape?