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Speed and Feed for 1/16"-27 NPT (01 Steel)

dalt.deuel

Plastic
Joined
Apr 19, 2018
Can anyone help me with speed and feed for a 1/16"-27 NPT tap.

Currently running it at

S20 F0.625


Using a .246" (D) Drill going Z-750

and running 1/16"-27 NPT tap Z-.350

Material is 0-1 Steel


Does that seem correct? I have not been getting that good of results with these Speeds and Feeds. Is my tap drill size correct?

Need to know for Monday morning, anything helps!!

-Dalton
 
Can anyone help me with speed and feed for a 1/16"-27 NPT tap.

Currently running it at

S20 F0.625


Using a .246" (D) Drill going Z-750

and running 1/16"-27 NPT tap Z-.350

Material is 0-1 Steel


Does that seem correct? I have not been getting that good of results with these Speeds and Feeds. Is my tap drill size correct?

Need to know for Monday morning, anything helps!!

-Dalton

20 rpm? :eek: that's like 1 sfpm.
Go with 50sfpm or so.
 
I calculated a feed of .7407 inch per minute with 20 rpm.

I agree. Dalt, are you using a tension/compression tap holder or rigid tapping? And is this lathe or mill? I'd consider thread milling if that's an option, I figure you get better thread forms when cutting tapered thread over using a tap.
 
tension/compression. i can use rigid tapping as well. Just have had problems the its pulling the threads out when it retracts. No option to use thread milling. this is being ran on a Haas Mill.

Will try at S20 F.7407 and report results Monday morning. thanks!
 
tension/compression. i can use rigid tapping as well. Just have had problems the its pulling the threads out when it retracts. No option to use thread milling. this is being ran on a Haas Mill.

Will try at S20 F.7407 and report results Monday morning. thanks!

Why are you running so slow? 20 RPM???? Haas Mills do rigid tap, I'm guessing your painfully slow RPM is tearing the threads, not the retract. Taps suck for tapered threads. Why is Threadmilling not an option?

Annealed O1 is gummy. Try tapping fluid and 500 RPM. If you don't know how to figure a Feed from that...you might have the cart before the horse.

R
 
Can anyone help me with speed and feed for a 1/16"-27 NPT tap.

Currently running it at

S20 F0.625


Using a .246" (D) Drill going Z-750

and running 1/16"-27 NPT tap Z-.350

Material is 0-1 Steel


Does that seem correct? I have not been getting that good of results with these Speeds and Feeds. Is my tap drill size correct?

Need to know for Monday morning, anything helps!!

-Dalton

you rpm to feed slightly off. many old machines have trouble stopping spindle and it turns extra and screws itself further in. when tap come out of hole you often see it snap back with the spring cause it was in extra into hole.
.
some steels you need to use a thick tapping fluid. that is coolant is not enough to prevent rough threads. trim tap heavy is a honey like thickness thats doesnt wash off with coolant easily. if applied and coolant used when done you will normally need to wipe off as its still on part. hard to describe but it works with some steels that tend to give rough threads easily
.
programming when M0 used it turns spindle and coolant off normally and you have to program turning spindle and coolant back on after M0
 
tension/compression. i can use rigid tapping as well. Just have had problems the its pulling the threads out when it retracts. No option to use thread milling. this is being ran on a Haas Mill.

Will try at S20 F.7407 and report results Monday morning. thanks!

I would be thread milling. Any tapered threads or any thread above 3/8" get thread milled here using Haas mills. Learning thread milling is very, very valuable.

Where are you in MI?
 
99% of time rough threads with certain metals is just need tapping fluid instead of coolant.
.
and obviously going slow rpm has nothing to do with problem as hand tapping is always done slow. although machine might have more trouble stopping at certain rpm
.
extension compression holder the spring force needs to be appropriate to the size of tap. you do not use a spring made for a big tap on a small tap. just saying a heavy spring used for a 1" dia tap is not the best to use with a 4-40 tap. if rpm to feed ratio is off or machine turns spindle extra when stopping then when tap leaves hole the spring tends to want to pull tap out of hole. this tap snap back when coming out of hole is often easily noticeable on some machines. if spring is too strong then it can pull out tap too hard when exiting hole
 








 
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