Hi therookie, thanks for the suggestion! The feature request for an internal thread milling calculator has been logged. We'll let you know here once it's available.

Thanks for the suggestion.

We've logged this feature for implementation.

The main challenge is that the calculation depends on knowing the actual geometry of the thread mill. The nominal cutter diameter alone is not enough — the crest flat or radius, thread pitch, and flank angle affect the effective pitch diameter of the cutter. Manufacturer specifications don't always provide all of this information, so some dimensions may need to be entered by the user.

There is also an additional complication: a thread mill follows a helical path rather than simply reproducing its 2D profile. This can introduce some profile distortion, particularly when using a relatively large cutter compared with the thread diameter.

The planned implementation would roughly work as follows:

Enter/select the desired thread and target pitch diameter.

Enter the thread mill diameter and crest flat or radius.

Calculate the effective pitch diameter of the cutter from its geometry.

Calculate the required toolpath diameter for the desired thread pitch diameter.

Ideally, compensate for the additional geometric error caused by the helical toolpath.

I'll likely add this calculator to either the Geometry or Threads tab.

The basic calculation should be fairly straightforward. The main thing I'll need to investigate is how far to take the helical-profile compensation and what cutter information can reasonably be expected from manufacturers/users.