03-31-2012, 07:45 PM
The problem with the cresting inserts Ed, is that they make this too easy.
Let's say you were making a 1/2-13 UNC thread. Now normally you would turn the diameter to something less than .500, so perhaps .496/.494 as that's the recommended diameter. With the cresting inserts you would leave the pre-threaded diameter at .500, and let the insert bring the O.D. down to finished sized. When you reach it, the pitch diameter is done too. Works every time.
You'd learn to love the beautiful, burr-free smooth threads such as you see here in the 316 stainless steel motorcycle axle I made for a friend:
![[Image: IMG_0398-r.jpg]](http://img.photobucket.com/albums/v466/kenm10759/wheel-adapter/IMG_0398-r.jpg)
Let's say you were making a 1/2-13 UNC thread. Now normally you would turn the diameter to something less than .500, so perhaps .496/.494 as that's the recommended diameter. With the cresting inserts you would leave the pre-threaded diameter at .500, and let the insert bring the O.D. down to finished sized. When you reach it, the pitch diameter is done too. Works every time.
You'd learn to love the beautiful, burr-free smooth threads such as you see here in the 316 stainless steel motorcycle axle I made for a friend: