coxsteve, sure what you say is true, and it will result in a really strong diff...but until i see a 1200 break an R31 axle that is done this way i'll have to stay a firm believer that there is nothing wrong with doing like this

it is how alot of diff shops do it and its only if they get billet axles that it is done differently...but even then i'd assume the spline is still cut on not rolled

ive never seen or heard of an axle failing coz the spline has been stripped off it, its always axles actually snapping. so the thread rolling vs cutting cant really be that much different in the real world