Rigid Tapping Feed Rates - STI vs Standard

[mayu]

Hello eM,

For rigid tapping applications, do feedrates change between STI and standard taps?

For example would the feedrate be the same for a 1/4-20 UNC and a 1/4-20 STI?

Thank you

[Leon82]

No

 

Yes

[JParis]

Tap feedrates are ultimately a factor of the "Threads per inch", ie pitch

The larger question is are you feeding tap in IPR or IPM? 

Using IPM.....

If IPM say 500 RPM x .05" Pitch = feedrate = 25.

If IPM say 800 RPM x .05" Pitch = feedrate = 40.

If you change the speed, the feedrate needs to be adjusted

 

Using IPR

If IPR  500 RPM the feedrate is F.05

If IPR  800 RPM the feedrate is F.05

That is constant regardless of the speed change

 

 

[mayu]

Thank you all. This was for a really scary part. The tapping went fine.