I think he had it right. The pin on my schon is a fair amount longer than the pin on my brothers old Joss. So the internal threads in the Shon shaft are deeper to accomadate the extra schon pin length. The Joss, with a shorter pin, would need less threads in the shaft to seat. So, theoretically, a Joss shaft could very well bottom out on the pin of a schon before the joint seats.