On the subject of threads, take a real close look at them. They are a "double thread", for each full turn of the rod, 360 degrees, there are two distinct threads cut into the rod. The thread type is called Acme, but this thread has a slight dip on the crown, the pointy top. An Acme thread was designed for power, extra load bearing, and the double thread part for speed. To verify this, use a piece of chalk to mark any one thread's crown while you turn the rod. In one full rotation, you will skip a thread.
Jim