On 1/26/2017 6:39 PM, Bob Engelhardt wrote:
I ordered a 20 degree cutter. 20 degrees seems the mostly likely angle.
...

I've posted this question on the HSM forum and a fellow there (Paul
Alciatore) played with my high-res 4-tooth scan and showed that my gear
has 20 PA _stub_ form teeth. I never hear of stub form teeth, but
they're regular teeth with the root & crest shortened. Makes them
stronger, they say.

His post is on page 3 of the HSM thread:
http://bbs.homeshopmachinist.net/thr...re-angle/page3