Feed and speed?

[Slixmix]

It's early and I'm a little confused. I have some drills that call out specific feeds and speeds. One says .010-.014 IPR (inch per rev?). Is this considered "chip load"? I use this formula to calculate my speed: RPM x "chip load" x # of flutes. Another tool (thread mill) calls out IPT (inch per tooth) .0012-.004. Is that also considered "chip load"? Coffee time!

[Fig sign]

First one is feed per revolution FR

Second one iz feed per tooth FZ

 

FR=FZ*number of teeth

 

Feed per minute is S*FR

[Slixmix]

Okay 1st tool is S1700 and .01-.014 IPR. I got a feed rate of 17. IPM

 

2nd tool is S4000 and .0012-.004 IPT. I got a feed rate of 4.8 IPM.

[Fig sign]

first is

f=1700*0.012=20.4 inch/per minute

 

Second is f=4000*0.0026*2 (if the drill is two-fluted )=20.8 INCH/PER MINUTE

[LEV]

on first one drill: 1700(rpm) x .012(ipr) x 2(# of fluts) =40.8(ipm)

on second thread mill: 4000(rpm) x .0026(ipt) = 10.4(ipm)

 

 

Lev

Westwood Precision Inc.

[Jaz]

Feed for drills are usually called out in Feed per Revolution (IPR), this is NOT the same as Feed per Tooth (IPT). We usually call them both 'chip load' but for drills the number of flutes is already factored in and does not apply to the equation.

1700rmp x .012ipr = 20.4ipm

For end mills one does need to factor the number of teeth into the equation.

4000rpm x .0026ipt x 2teeth = 20.8ipm

[LEV]

oops:

 

I agree with you Jaz.

 

Lev.