I have Robert Sorby threading tools. I made a case for them. I have 10,16 and 20 threads per inch. For the olive I used 10 TPI. I'm no good with the tool support bar, so it stayed in the case for this project.
I have found MDF is good for practice. It's no good to use in threaded project, but it feels the same as wood chasing threads.
I want to do right, but not right now. Gillian Welch