[fourperf]

Hi guys. I have been cutting non standard size threads (eg 2.75 - 12) for some things I have been making. are there formulas to figure out major and minor dimensions for different pitches that someone can share. I am self taught and find the machinists handbook overwhelming.

Thanks a lot

[78nova]

I do not have an exact answer but take a look at;

http://www.skilledtradesmath.com/fil...ad_Cutting.ppt

maybe you can find what you are looking for.

[basalt]

I just posted my thoughts etc. on thread cutting. Basically if you are cutting a UN or UNR thread the external depth of thread is .61343 X pitch measured from the exact nominal ouside diameter. The internal depth of thread is
.57252 X pitch measured from the exact basic minor diameter which is BASIC MINOR DIA. = basic O.D. – (2 x .54127P). Hope this helps,
here is the link to my site.
http://un-unr-unj-threads.tripod.com/index.html
Colin

[fourperf]

thanks a lot guys

mark