faced with having to cut a short length of M12x1.75 onto a 12mm bar, and
finding that the (cheapo) M12x1.75 die wasn't really up to it, I had a go at
getting the lathe to cut threads.
after a certain amount of discussion, calculation and guesswork (a mate of
mine was around at the time) we decided on which setting on the gearbox
would do 1.75mm pitch (oddly, it's not labelled - various other metric
pitches are, and the gearbox is metric-or-imperial).
I then ground up a 60-degree pointy tool, as I don't have a suitable thread
chaser, and, putting a bit of spare material in the chuck, set forth to see
if I could cut threads, which, after a few false starts, I did get it to do
a rather rough and 'orrible job, which I could then clean up with the
The main problem seems to be getting it to cut smoothly - I was operating at
very low speed, 'cos otherwise it's difficult to control, particularly as I
was only aiming to produce about 12mm or so of thread; just enough to screw
a nut onto.
Apart from having a proper chaser, any hints and tips about the process of
cutting threads on the lathe?
15 years ago