Great Question. We ran a lot of these parts. The main threading cycle takes a long time to run. If the tool has worn and the nut doesn't go on, instead of running the main cycle again. Just make the offset adjustment and only run the last 3 passes. Also there was a bit of deflection happening on this part. The last 3 passes allowed me to use the same tool but with a different wear offset to get a consistent result. This also allowed us to machine Taper threads and account for deflection well as wear.
Let me guess, a bolt for some sort of a crane?
No idea. As a machine shop we make lots of different stuff and often don't know the end use.
Why the last 3 threading passes after finish pass on the od? Not spring passes, right?
Great Question. We ran a lot of these parts. The main threading cycle takes a long time to run. If the tool has worn and the nut doesn't go on, instead of running the main cycle again. Just make the offset adjustment and only run the last 3 passes. Also there was a bit of deflection happening on this part. The last 3 passes allowed me to use the same tool but with a different wear offset to get a consistent result. This also allowed us to machine Taper threads and account for deflection well as wear.
@@M3Machining thanks for the answer, that explains a lot.