Some cool machining aluminum images:
Deforming Undersized Regular threads to fit a Metric T-Ring
Image by nebarnix
It works!
Lathed 12mm Parfocal Extender
Image by nebarnix
33mm to 45mm for quick but amazing lomos.
The surface finish could use a touch up. The tolerances on this piece have been pretty tight and I wanted to make confident it would match ahead of I invested also much time. RMS threads are a bitch.