percentage of thread

[4AXIS]

What is the difference between the theoretical percentage of a thread compared to the percentage of a full thread. When I use the formula tpi*(tap od - drill od/.01299) I come up with a higher percentage than what is on the drill and tap charts.

 

[mrainey]

Maybe the chart is factoring in a probable oversize condition for the drilled hole.

Manufacturing Freeware and Shareware

http://mrainey.freeservers.com

 

[unclesyd]

Here is website that may be of help.

http://www.newsontool.com/01_08-11.html#thread_constants_for_various_percentages

or

http://www.newsontool.com