Re: Single Point Left Hand Threading

m. allan noah

On Sun, Mar 7, 2021 at 8:24 AM Guenther Paul <> wrote:

You can through that book away American and metric thread is 60 degree not 58 you set the compound on 30 degree.
The British withworth thread is 55 degree

Sigh. Think about it. The angle of the compound in-feed does not set
the angle of the thread- the shape of the tool does. The 29 degree
thing is so you always cut a little on the back side, leaving a clean
flank, but do the bulk of the cutting in a direction that keeps the
backlash taken up in the compound. So, the angle does not matter at
all. I thread with the cross feed going straight in, and don't touch
the compound at all, regardless of handedness. I certainly don't make
a 0 degree thread :)


"well, I stand up next to a mountain- and I chop it down with the edge
of my hand"

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