Re: Lathe threading

Dan,

We do a tremendous amount of single point threading on my lathes.
For best quality of thread we use full-profile inserts, each pitch
requires a separate insert. A little pricey until you build up a
stock of various common pitches. The good news is the dealers will
sell these inserts in single quantities. 3/8" IC laydown style is
the one I like. They're available in pitches from 8tpi down to 72.

The nice thing about a full-profile insert is it has the correct root
radius and tops the thread so you have a product that approaches
rolled threads in appearance.

The full-profiles are easier to use than plain 60 degreee type. For
instance, on your 1/2-20 thread...you could start with full 1/2"
stock, cut threads until the correct pitch diameter is reached and
the major diameter of the thread will have been brought down to
correct size and bur-free.

We use a 30 degree infeed with the last pass a clean-up with no
infeed. Number of passes used is the control's default which it
calculates based on the programmed depth of the first pass.

Doug

--- In CAD_CAM_EDM_DRO@y..., "Dan Mauch" <dmauch@s...> wrote:
> I was looking up in the Carbaloy catalog to buy a new threading tool
> insert when I can across the various methods of CNC threading. Some
use
> what is called the modified flank infeed, standard infeed, alternate
> flank infeed, radial infeed. So now I understand how your controller
> used a canned cycle for cutting the threads at less than 60
degrees. I
> have deduces that my program just uses the radial infeed method.
> Dan
>