Machine Tapping
 

I've got this urge to own a tapping head, so I've started doing a little
reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary dramatically
depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That seems
insanely fast to me. Are you guys who do this really tapping holes in a
fraction of a second?

Seems like for small jobs the clamping and positioning requirements to do
that would take longer than tapping a couple holes by hand.

Machine Tapping
 

"Bob La Londe" wrote in message
...
I've got this urge to own a tapping head, so I've started doing a little
reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary dramatically
depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That seems
insanely fast to me. Are you guys who do this really tapping holes in a
fraction of a second?

Seems like for small jobs the clamping and positioning requirements to do
that would take longer than tapping a couple holes by hand.


Oh, heck. They also list aluminum on their chart at 90-100. Now I am
really confused.

At 95 that comes out as 6.175. That makes more sense, but then it becomes a
problem to turn that slow and still apply full power with most machines guys
like me can afford.

And why do they list aluminum at 90-100 and many of the milling sites list
aluminum from 500 to as much as 1200?

I had thought up until this moment SFM was SFM.

Machine Tapping
 

On 12/14/2010 10:29 AM, Bob La Londe wrote:
"Bob La Londe" wrote in message
...
I've got this urge to own a tapping head, so I've started doing a
little reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary
dramatically depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That
seems insanely fast to me. Are you guys who do this really tapping
holes in a fraction of a second?

Seems like for small jobs the clamping and positioning requirements to
do that would take longer than tapping a couple holes by hand.


Oh, heck. They also list aluminum on their chart at 90-100. Now I am
really confused.

At 95 that comes out as 6.175. That makes more sense, but then it
becomes a problem to turn that slow and still apply full power with most
machines guys like me can afford.

And why do they list aluminum at 90-100 and many of the milling sites
list aluminum from 500 to as much as 1200?

I had thought up until this moment SFM was SFM.




It all depends on the tap I would say.. If its a standard HSS tap with
no coatings, we normally run them at 100 RPM with oil in steels, and
coolant in plastic or aluminium. If we get into some type of production,
then we look at better taps so we can get faster feedrates.

We tend not to push a tap too hard, because it is normally a final
operation, and its a bitch to drill them out if they break.

Machine Tapping
 

On 12/14/2010 07:29 AM, Bob La Londe wrote:
"Bob La Londe" wrote in message
...
I've got this urge to own a tapping head, so I've started doing a
little reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary
dramatically depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That
seems insanely fast to me. Are you guys who do this really tapping
holes in a fraction of a second?

Seems like for small jobs the clamping and positioning requirements to
do that would take longer than tapping a couple holes by hand.


Oh, heck. They also list aluminum on their chart at 90-100. Now I am
really confused.

At 95 that comes out as 6.175. That makes more sense, but then it
becomes a problem to turn that slow and still apply full power with most
machines guys like me can afford.

??

95 / (0.26 * 0.25) = 1462

And why do they list aluminum at 90-100 and many of the milling sites
list aluminum from 500 to as much as 1200?

I had thought up until this moment SFM was SFM.

Maybe the operation does matter.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

Machine Tapping
 

"Tim Wescott" wrote in message
...
On 12/14/2010 07:29 AM, Bob La Londe wrote:
"Bob La Londe" wrote in message
...
I've got this urge to own a tapping head, so I've started doing a
little reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary
dramatically depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That
seems insanely fast to me. Are you guys who do this really tapping
holes in a fraction of a second?

Seems like for small jobs the clamping and positioning requirements to
do that would take longer than tapping a couple holes by hand.


Oh, heck. They also list aluminum on their chart at 90-100. Now I am
really confused.

At 95 that comes out as 6.175. That makes more sense, but then it
becomes a problem to turn that slow and still apply full power with most
machines guys like me can afford.

??

95 / (0.26 * 0.25) = 1462

And why do they list aluminum at 90-100 and many of the milling sites
list aluminum from 500 to as much as 1200?

I had thought up until this moment SFM was SFM.

Maybe the operation does matter.


I totally hosed that one hey Tim. LOL.

Machine Tapping
 

I run pretty conservative numbers to make sure my customers have reliability
and efficiency.

Generally, I run taps at 1/3 the drilling RPM and plan on needing 200% of
the HP requirement for drilling. ...Cut tap, HSS.

I use the following chart to estimate those numbers:

http://tinyurl.com/ToolSpeeds
or
http://www.multi-drill.com/drill-speed-chart.htm

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill
TWITTER: http://twitter.com/AutoDrill
FACEBOOK: http://tinyurl.com/AutoDrill-Facebook

V8013-R

Machine Tapping
 

"Joe AutoDrill" wrote in message
...
I run pretty conservative numbers to make sure my customers have
reliability and efficiency.

Generally, I run taps at 1/3 the drilling RPM and plan on needing 200% of
the HP requirement for drilling. ...Cut tap, HSS.

I use the following chart to estimate those numbers:

http://tinyurl.com/ToolSpeeds
or
http://www.multi-drill.com/drill-speed-chart.htm


Thanks, Joe. You those are going in the binder I keep out in the shop.











Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill
TWITTER: http://twitter.com/AutoDrill
FACEBOOK: http://tinyurl.com/AutoDrill-Facebook

V8013-R

Machine Tapping
 

On Tue, 14 Dec 2010 14:06:10 -0500, "Joe AutoDrill"
wrote:

I run pretty conservative numbers to make sure my customers have reliability
and efficiency.

Generally, I run taps at 1/3 the drilling RPM and plan on needing 200% of
the HP requirement for drilling. ...Cut tap, HSS.

I use the following chart to estimate those numbers:

http://tinyurl.com/ToolSpeeds
or
http://www.multi-drill.com/drill-speed-chart.htm


Man, I have a radial arm drill and a heavy duty CNC mill and i only go
about 1/3 of these numbers. IMHO, a typical HSM ain't got a chance
with light equipment at these speeds. Keep in mind these numbers are
for production shops.

Just my 2 cents

Karl

Machine Tapping
 

"Karl Townsend" wrote in message
...
On Tue, 14 Dec 2010 14:06:10 -0500, "Joe AutoDrill"
wrote:

I run pretty conservative numbers to make sure my customers have
reliability
and efficiency.

Generally, I run taps at 1/3 the drilling RPM and plan on needing 200% of
the HP requirement for drilling. ...Cut tap, HSS.

I use the following chart to estimate those numbers:

http://tinyurl.com/ToolSpeeds
or
http://www.multi-drill.com/drill-speed-chart.htm


Man, I have a radial arm drill and a heavy duty CNC mill and i only go
about 1/3 of these numbers. IMHO, a typical HSM ain't got a chance
with light equipment at these speeds. Keep in mind these numbers are
for production shops.

Just my 2 cents

Karl

Karl is mostly right here when it comes to RPM. The charts are conservative
in some respects (lower RPM than some achieve with the same HSS tooling) but
they do presume proper coolant, sharp tooling, rigid set-up, etc.

The numbers work just fine for me on my cheapo drill presseses here in the
shop, but I'm very careful to always use lubrication such as cutting oil,
etc.

As for the feed rate... Most people can't "program" their feed rate so it's
not a huge issue. with almost all materials, a lesser feed rate won't do
much harm. In stainless, the exact opposite is true. A lesser feed rate
causes more heat build up and that is a very bad thing in stainless.

Overall, on a manaully fed drill press with some sort of cutting fluid to
cool the drill, the numbers on that chart should be safe for just about
everything you do.
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill
TWITTER: http://twitter.com/AutoDrill
FACEBOOK: http://tinyurl.com/AutoDrill-Facebook

V8013-R

Machine Tapping
 

On Tue, 14 Dec 2010 08:23:28 -0700, "Bob La Londe"
wrote:

I've got this urge to own a tapping head, so I've started doing a little
reading on tapping speeds. One formula I have read is:

For inch taps
RPM = SFM / (.26 * Tap OD)

http://www.newyorktwistdrill.com/tap...l_data_03.html

A middle of the road SFM for aluminum ( I know it can vary dramatically
depending on hardness, alloy, etc ) is about 600.

When I plug that in for a 1/4" tap it comes up with 9230.769 That seems
insanely fast to me. Are you guys who do this really tapping holes in a
fraction of a second?

Seems like for small jobs the clamping and positioning requirements to do
that would take longer than tapping a couple holes by hand.



Obviously, I do it in a NON home shop enviroment, but in
aluminum....6061, for example, I'll run at between 600 and 800 RPM
with flood water soluble coolant.

For a REAL production run....a few thousand holes, I'll set up the
reversing tapping head on the VMC and spin that at about 2500 RPM

But that is just me....your mileage may vary

Mike

Machine Tapping
 

On 2010-12-16, wrote:
A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at 10,000 RPM.
That's not just me.
Your mileage won't vary.

I don't doubt that at all...I am, however, using a fairly old Hurco
that couldn't spin that fast with a bullet at the set-up dudes
head....that's me, by the way.

And the reason for the 2500 speed is that that is all the faster the
head is rated at. I have a smaller one that I use for taps #10 and
under that will take up to 4500.

At 10,000 RPM, a 20 TPI tap would travel 8.33 inches per second.

At 2,500 RPM, 2.08 inches per second.

i

Machine Tapping
 

On Wed, 15 Dec 2010 22:14:32 -0600, Ignoramus22945
wrote:

On 2010-12-16, wrote:
A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at 10,000 RPM.
That's not just me.
Your mileage won't vary.

I don't doubt that at all...I am, however, using a fairly old Hurco
that couldn't spin that fast with a bullet at the set-up dudes
head....that's me, by the way.

And the reason for the 2500 speed is that that is all the faster the
head is rated at. I have a smaller one that I use for taps #10 and
under that will take up to 4500.

At 10,000 RPM, a 20 TPI tap would travel 8.33 inches per second.

At 2,500 RPM, 2.08 inches per second.

i

Yea, these production guys live in a whole 'nuther world.

All my CNC tapping is at 100 RPM and that's plenty fast. For the one
of jobs I do increasing tap speed from 100 to 10,000 RPM would save a
couple minutes out of my day. And maybe not that, I use machine run
time to set up the next op or clean the shop. Or if its a long
program, start making parts on another machine.

Anyway, if you can do something else while your machine runs; speed is
not an issue for us HSM types. Now breaking a tap in a part IS.

Again, just my two cents. I go slow and try real hard not to **** up
and break ****. Takes less effort in the long run.

Karl

Machine Tapping
 

On 2010-12-16, Karl Townsend wrote:
On Wed, 15 Dec 2010 22:14:32 -0600, Ignoramus22945
wrote:

On 2010-12-16, wrote:
A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at 10,000 RPM.
That's not just me.
Your mileage won't vary.

I don't doubt that at all...I am, however, using a fairly old Hurco
that couldn't spin that fast with a bullet at the set-up dudes
head....that's me, by the way.

And the reason for the 2500 speed is that that is all the faster the
head is rated at. I have a smaller one that I use for taps #10 and
under that will take up to 4500.

At 10,000 RPM, a 20 TPI tap would travel 8.33 inches per second.

At 2,500 RPM, 2.08 inches per second.

i

Yea, these production guys live in a whole 'nuther world.

All my CNC tapping is at 100 RPM and that's plenty fast. For the one
of jobs I do increasing tap speed from 100 to 10,000 RPM would save a
couple minutes out of my day. And maybe not that, I use machine run
time to set up the next op or clean the shop. Or if its a long
program, start making parts on another machine.

Anyway, if you can do something else while your machine runs; speed is
not an issue for us HSM types. Now breaking a tap in a part IS.

Again, just my two cents. I go slow and try real hard not to **** up
and break ****. Takes less effort in the long run.

Karl

I feel the same, yet, the production world is fascinating.

i

Machine Tapping
 

John R. Carroll wrote in
rec.crafts.metalworking on Wed, 15 Dec 2010 17:11:57 -0800:

For a REAL production run....a few thousand holes, I'll set up the
reversing tapping head on the VMC and spin that at about 2500 RPM

But that is just me....your mileage may vary

Mike

A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at 10,000 RPM.
That's not just me.
Your mileage won't vary.

At work we just got two new robodrills. Smaller than CAT 40. And boy
can it move. It was tapping some small parts so fast, you couldn't
see the spindle stop and reverse. If tapping blind holes with a roll
(forming) tap, you have to go slow to give the coolant a chance to
escape. The thing sounds like a dental drill when milling.
--

Dan H.
northshore MA.

Machine Tapping
 

"Karl Townsend" wrote in message
...
On Wed, 15 Dec 2010 22:14:32 -0600, Ignoramus22945
wrote:

On 2010-12-16, wrote:
A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at 10,000
RPM.
That's not just me.
Your mileage won't vary.

I don't doubt that at all...I am, however, using a fairly old Hurco
that couldn't spin that fast with a bullet at the set-up dudes
head....that's me, by the way.

And the reason for the 2500 speed is that that is all the faster the
head is rated at. I have a smaller one that I use for taps #10 and
under that will take up to 4500.

At 10,000 RPM, a 20 TPI tap would travel 8.33 inches per second.

At 2,500 RPM, 2.08 inches per second.

i

Yea, these production guys live in a whole 'nuther world.

All my CNC tapping is at 100 RPM and that's plenty fast. For the one
of jobs I do increasing tap speed from 100 to 10,000 RPM would save a
couple minutes out of my day. And maybe not that, I use machine run
time to set up the next op or clean the shop. Or if its a long
program, start making parts on another machine.

Anyway, if you can do something else while your machine runs; speed is
not an issue for us HSM types. Now breaking a tap in a part IS.

I hear that. Lately my jobs all take hours and even days rather than
minutes. I spent the last week designing and building 3 unique parts for
somebody else and modifying one somebody else made for them so it would
actually work. My anxiety level has been above my eyebrows. If it was not
for having to stop and watch the machines run and go take care of my clients
at my day job I don't think I'ld have relaxed at all. LOL. It's one of the
most fun week I have had in a long time.

Machine Tapping
 

On Wed, 15 Dec 2010 22:14:32 -0600, Ignoramus22945
wrote:

On 2010-12-16, wrote:
A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at 10,000 RPM.
That's not just me.
Your mileage won't vary.

I don't doubt that at all...I am, however, using a fairly old Hurco
that couldn't spin that fast with a bullet at the set-up dudes
head....that's me, by the way.

And the reason for the 2500 speed is that that is all the faster the
head is rated at. I have a smaller one that I use for taps #10 and
under that will take up to 4500.

At 10,000 RPM, a 20 TPI tap would travel 8.33 inches per second.

At 2,500 RPM, 2.08 inches per second.

i

Yeah, about that...one job I do fairly often involves a ew hunderd
#6-32 taps 7/16" deep...

....I spin at 4000 RPM and the feed is about 115 IPM. Perfect world
number is 125 IPM, but I always run the feed just a bit under nominal
so that the tap is always pulling a bit....less chance of
crowding...and the clutch will take care of the rest.

Mike

Machine Tapping
 

John R. Carroll wrote in
rec.crafts.metalworking on Thu, 16 Dec 2010 15:22:48 -0800:

dan wrote:
John R. Carroll wrote in
rec.crafts.metalworking on Wed, 15 Dec 2010 17:11:57 -0800:

For a REAL production run....a few thousand holes, I'll set up the
reversing tapping head on the VMC and spin that at about 2500 RPM

But that is just me....your mileage may vary

Mike

A Fanuc Robodrill (CAT 40 VMC) will peck tap 1/4-20 UNC holes at
10,000 RPM. That's not just me.
Your mileage won't vary.

At work we just got two new robodrills. Smaller than CAT 40. And boy
can it move.

I've seen these walk a long way (relatively) in as little as a single shift.

You mean across the floor? I think ours are bolted down.
I was referring to the speed of the axis movement and tool changes.

It was tapping some small parts so fast, you couldn't
see the spindle stop and reverse. If tapping blind holes with a roll
(forming) tap, you have to go slow to give the coolant a chance to
escape.

Or use taps relieved for this purpose. They have a small (0.020") hole
through the center of them.
The hole is made with a wire that gets disolved out at the end of the
manufacturing process.
You might want to pass that along.

I will! I've seen the taps that have a grove down one side, but not
on the very small ones (4-40 to 0-80). Do you have a brand name?


Something else. Measure the thread depth between holes. Your jaw will drop
when you see how close thay are to being identical.

Should be. But I just look. I'm in the lathe dept.
(I work with two citizen L25s and one M20)

--

Dan H.
northshore MA.

Machine Tapping
 

On Tue, 14 Dec 2010 17:26:03 -0500, Karl Townsend
wrote:

On Tue, 14 Dec 2010 14:06:10 -0500, "Joe AutoDrill"
wrote:

I run pretty conservative numbers to make sure my customers have reliability
and efficiency.

Generally, I run taps at 1/3 the drilling RPM and plan on needing 200% of
the HP requirement for drilling. ...Cut tap, HSS.

I use the following chart to estimate those numbers:

http://tinyurl.com/ToolSpeeds
or
http://www.multi-drill.com/drill-speed-chart.htm


Man, I have a radial arm drill and a heavy duty CNC mill and i only go
about 1/3 of these numbers. IMHO, a typical HSM ain't got a chance
with light equipment at these speeds. Keep in mind these numbers are
for production shops.

Just my 2 cents

Karl

Ill have to check them. I was running a radial arm drill yesterday, but
it only had a 3" bit in it.

Cinci with a 12' arm.....

Gunner

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