Father tries to help, ends up gouging threads on reciver....

[sharpshooter]

Please explane the hobbing operation of a receiver before threads are cut.

Hobbing is not done before the threads are cut. I think you misinterpreted what I said. Thread milling is a CNC operation, and before they used CNC equipment, they used a hob mill. A hob mill works the same way, only mechanical.

[stangfish]

Hobbing is not done before the threads are cut. I think you misinterpreted what I said. Thread milling is a CNC operation, and before they used CNC equipment, they used a hob mill. A hob mill works the same way, only mechanical.

OK, We used to hob gears at a shop I worked in durring the early 80's. The thread hobbing on an Id I could not picture. .

[Captlink]

Hobbing is not done before the threads are cut. I think you misinterpreted what I said. Thread milling is a CNC operation, and before they used CNC equipment, they used a hob mill. A hob mill works the same way, only mechanical.

I used a gear hobber as a apprentice machinist but have never seen them used for threading.I know how bad threading can be no matter how they are formed and a truing operation is SOP in my experience.I hope the op can have the problem repaired in a cost effective way.