Cutting oil on lathe bits

[Bob Engelhardt]

The "Thatlazymachinist" on YouTube had a video that explained that the
purpose of cutting oil was to enhance the flow of the chip on the face
of the cutting tool. I posted this comment question, but I'm getting
impatient & I expect that someone here has the answer.

[quote]
If cutting oil helps the chip flow along the face of the tool, it needs
to be ON the face of the tool. But if it is applied to the stock ahead
of the cut, how does it get from the surface of the stock to the face of
the tool? This seems especially unlikely given that the chip is in
constant contact with the face (how would oil get between them?)
[/quote]

Thanks,
Bob

[Jim Wilkins]

"Bob Engelhardt" <BobEng...@comcast.net> wrote in message
news:o1ir2...@news6.newsguy.com...

> get between them?)?
> [/quote]
>
> Thanks,
> Bob

I've wondered about that, and if the oil moves as hot vapor instead of
liquid. There isn't all that much difference between low speed
threading with and without oil. I think oil might improve the surface
finish somewhat and reduce the torque when I pull the belt to run the
bit up hard against a shoulder.

It could be informative to measure the torque to slowly hand crank the
spindle on a roughing cut with the feed engaged, first without and
then with oil. I don't know if a Kill-A-Watt would indicate power
delivered to the spindle clearly enough to be useful.
--jsw

[Cydrome Leader]

Whoever made that quite seems to think oil is like a thin layer of paint
and can't flow at all or something like that. It's a pretty easy test to
do too. Cut something that was oiled. Is the cutter oily? Ok, done.

[Gunner Asch]

>constant contact with the face (how would oil get between them?)?
>[/quote]
>
>Thanks,
>Bob

It flows on. It only takes a thou or two to float a chip


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[Bob Engelhardt]

On 11/29/2016 3:11 PM, Cydrome Leader wrote:
> Whoever made that quite seems to think oil is like a thin layer of paint
> and can't flow at all or something like that. It's a pretty easy test to
> do too. Cut something that was oiled. Is the cutter oily? Ok, done.
>

Good point. I did that, being careful to not get oil on the tool before
starting. And the tool stayed clean! Only makes me more confused.

Bob

[Bob Engelhardt]

On 11/29/2016 10:17 PM, Gunner Asch wrote:

> It flows on. It only takes a thou or two to float a chip

That seems reasonable, but:
- the stock is moving MUCH faster than the oil can flow (100 FPM = 20 in
per second). By the time that the oil starts to flow over the cut edge,
the tool is long gone.
- the tool is constantly cutting, so that the chip is in constant (high
pressure) contact with the tool face. How does the oil get between them?

This idea of putting oil on the stock is making less and less sense to
me. I'm beginning to think that it is done because it's always been done.

What makes sense is to put the oil on the tool before starting the cut.
Putting it on the tool during the cut _might_ work (if the oil could
somehow flow under the chip).

Bob

[Jim Wilkins]

"Bob Engelhardt" <BobEng...@comcast.net> wrote in message

news:o1qsj...@news6.newsguy.com...

You could start a cut dry and then add oil to see how much difference
it makes.

[dca...@krl.org]

On Thursday, December 1, 2016 at 11:30:48 PM UTC-5, Bob Engelhardt wrote:

> This idea of putting oil on the stock is making less and less sense to
> me. I'm beginning to think that it is done because it's always been done.
>
> What makes sense is to put the oil on the tool before starting the cut.
> Putting it on the tool during the cut _might_ work (if the oil could
> somehow flow under the chip).
>
> Bob

One of the things the oil does is cool the tool. So it makes sense even if it never gets to the cutting edge.

Dan

[et...@whidbey.com]

I have been machining metal for over 40 years and still don't quite
understand how the cutting oil on the stock gets between the tool and
the work. But it does as evidenced by improved finish of better chip
control or less chip welding and so on. However, directing high
pressure coolant right at the point where the cutting tool meets the
work is even more effective.
Eric

[edhun...@gmail.com]

You're not alone. No one understands it. <g> It's been studied since the 1920s. There was a lot of research going on in the 1970s. Results were somewhat contradictory -- some studies showed an extremely fast capillary action that draws the fluid in, and others did not.

A few things are known. The edge of the cutting-edge/workpiece interface (the periphery of a bar turned on a lathe, for example) sets up the behavior of the tool in the cut. When that outer edge of the cut is lubricated, the whole cut surface tends to be cleaner.

It's also true that oil lubricates the chip as it flows over the tool, reducing the compression load right at the cutting edge. That may contribute to better finishes.

Some researchers have gone to great lengths to figure this out, including the use of completely clear "tools" made of aluminum oxide, and high-speed photography. Still, the results were not really conclusive.

BTW, there are quite a few phenomena in metalworking that are not completely understood. For another example, no one knows why gage blocks wring. Forget what you may have heard -- I've spent hours interviewing the world's top experts on the subject. They just don't know.

--
Ed Huntress

[Martin Eastburn]

I did some grinding on my lathe some years ago. The stone was sitting
in a pool of oil - and I shook it 'dry'. Tool post grinder cut a nice
clean finish. Small grain showing. The stone naturally shot the oil
outward and got dry so when the other half of the work was ground (it
was in the jaws) - the measurement and even a fingernail ran over the
'edge' between grinding - both smooth but the grain showing was obvious.
The only difference was the oil that worked on the surface.

My take on the whole thing - not oil between but the working surface
isn't as hot with oil pouring over it - without it tends to tear due to
melting temp on the very edge due to heat. It makes for a rougher
surface than when cooled with a flood.

As far as the blocks I always thought it was atomic friction. The
surface is so fine that atoms touch. Rough surface allows only few to
touch.

Martin

[Jim Wilkins]

"Martin Eastburn" <lion...@consolidated.net> wrote in message
news:gFq0A.101591$7J2....@fx03.iad...

>I did some grinding on my lathe some years ago. The stone was
>sitting
> in a pool of oil - and I shook it 'dry'. Tool post grinder cut a
> nice
> clean finish. Small grain showing. The stone naturally shot the
> oil
> outward and got dry so when the other half of the work was ground
> (it was in the jaws) - the measurement and even a fingernail ran
> over the
> 'edge' between grinding - both smooth but the grain showing was
> obvious.
> The only difference was the oil that worked on the surface.
>
> My take on the whole thing - not oil between but the working surface
> isn't as hot with oil pouring over it - without it tends to tear due
> to
> melting temp on the very edge due to heat. It makes for a rougher
> surface than when cooled with a flood.
>
> As far as the blocks I always thought it was atomic friction. The
> surface is so fine that atoms touch. Rough surface allows only few
> to touch.
>
> Martin
>

Do steel (free electrons) and ceramic (bound electrons) blocks wring
differently?
--jsw

[edhun...@gmail.com]

No. Assuming a brand-new finish on each, they wring and hold about the same. We tried this when Mitutoyo was my client. We made stacks of mixed steel and ceramic blocks, and they held together with the same force.

--
Ed Huntress

[pyotr filipivich]

Gunner Asch <gunne...@gmail.com> on Tue, 29 Nov 2016 19:17:26 -0800
typed in rec.crafts.metalworking the following:

>On Mon, 28 Nov 2016 21:58:42 -0500, Bob Engelhardt
><BobEng...@comcast.net> wrote:
>>The "Thatlazymachinist" on YouTube had a video that explained that the
>>purpose of cutting oil was to enhance the flow of the chip on the face
>>of the cutting tool. I posted this comment question, but I'm getting
>>impatient & I expect that someone here has the answer.
>>
>>[quote]
>>If cutting oil helps the chip flow along the face of the tool, it needs
>>to be ON the face of the tool. But if it is applied to the stock ahead
>>of the cut, how does it get from the surface of the stock to the face of
>>the tool? This seems especially unlikely given that the chip is in
>>constant contact with the face (how would oil get between them?)?
>>[/quote]
>>
>>Thanks,
>>Bob
>
>It flows on. It only takes a thou or two to float a chip
>

If memory serves from tech school, the cutting oil doesn't
lubricate the chip, so much as cool the chip & tool. (After all,
where the tool meets the metal,there isn't room for anything else.
Cutting oil is last on the scene.)

FWIW: I first read the subject line as meaning "how does one cut
oil on a lathe?"
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

[Jim Wilkins]

"pyotr filipivich" <ph...@mindspring.com> wrote in message
news:lvm54ctpdc3gqse99...@4ax.com...

http://bbs.homeshopmachinist.net/archive/index.php/t-20828.html
Sulfur isn't a coolant but it bonds to freshly exposed surfaces.
-jsw

[Martin Eastburn]

In my handbook of Metrology Version 1.1 By Nobuo Suga Mitutoyo Institute
of Metrology - America

Metal to ceramic is a no-no. Keep like kinds together. However
it is done...

On page 3-10 or pp 44 - steel gage block wringing to optical parallel,
wring to two Ceramic Gage Blocks (2" and 1") - then two more steel gage
blocks wringing on the end.- 5 surfaces at once.

"High degree of flatness as well as surface "roughness" are required to
achieve this Phenomenon called winging."

"The winging layer between blocks are in the range of 25 nano-meter.
or for the imperial - .000001 in."

Martin

[Bob Engelhardt]

On 12/2/2016 3:38 PM, edhun...@gmail.com wrote:
> You're not alone. No one understands it. <g> It's been studied since the 1920s. There was a lot of research going on in the 1970s. Results were somewhat contradictory -- some studies showed an extremely fast capillary action that draws the fluid in, and others did not.

> ...

Thanks - that's good to know: I can stop wasting time Googling it. Bob

[Bob Engelhardt]

On 12/3/2016 10:10 AM, Jim Wilkins wrote:
> http://bbs.homeshopmachinist.net/archive/index.php/t-20828.html
> Sulfur isn't a coolant but it bonds to freshly exposed surfaces.

Thanks - the reply there explaining the 2 "regimes" of lubrication was
especially interesting.

[edhun...@gmail.com]

On Saturday, December 3, 2016 at 11:03:57 PM UTC-5, Martin Eastburn wrote:
> In my handbook of Metrology Version 1.1 By Nobuo Suga Mitutoyo Institute
> of Metrology - America
>
> Metal to ceramic is a no-no. Keep like kinds together. However
> it is done...
>
> On page 3-10 or pp 44 - steel gage block wringing to optical parallel,
> wring to two Ceramic Gage Blocks (2" and 1") - then two more steel gage
> blocks wringing on the end.- 5 surfaces at once.
>
> "High degree of flatness as well as surface "roughness" are required to
> achieve this Phenomenon called winging."
>
> "The winging layer between blocks are in the range of 25 nano-meter.
> or for the imperial - .000001 in."
>
> Martin

If that photo showing the stack of mixed gage blocks is the one I think it is, it's one I shot -- of Suga's hand. <g>

Mitutoyo's gage-block expert (not Suga; he's head of education) is one of the people I consulted when I wrote about it. The one I quoted is a physicist at NIST, Ted Doiran.

--
Ed Huntress

[edhun...@gmail.com]

That is a really good explanation. I might add one detail: it's not clear to me which types of lubrication are involved, but some lubricants not formulated for cutting (such as motor oil) can cause a cutting edge to skate over the work if the machine isn't sufficiently rigid or if the cut isn't sufficiently aggressive. This is why I cringe when people discuss cooking up their own brews of cutting oil, including the use of ATF. I have no idea how any individual concoctions perform, but the chance you'll get that combination of normal lubrication and extreme-pressure lubrication right seems pretty slim. Unless you use a lot of it and like to experiment, I'm strongly in favor of buying the stuff that's made and tested to do the job right.

--
Ed Huntress

[Martin Eastburn]

On 12/4/2016 2:34 AM, edhun...@gmail.com wrote:
> On Saturday, December 3, 2016 at 11:03:57 PM UTC-5, Martin Eastburn wrote:
>> In my handbook of Metrology Version 1.1 By Nobuo Suga Mitutoyo Institute
>> of Metrology - America
>>
>> Metal to ceramic is a no-no. Keep like kinds together. However
>> it is done...
>>
>> On page 3-10 or pp 44 - steel gage block wringing to optical parallel,
>> wring to two Ceramic Gage Blocks (2" and 1") - then two more steel gage
>> blocks wringing on the end.- 5 surfaces at once.
>>
>> "High degree of flatness as well as surface "roughness" are required to
>> achieve this Phenomenon called winging."
>>
>> "The winging layer between blocks are in the range of 25 nano-meter.
>> or for the imperial - .000001 in."
>>
>> Martin
>
> If that photo showing the stack of mixed gage blocks is the one I think it is, it's one I shot -- of Suga's hand. <g>
>
> Mitutoyo's gage-block expert (not Suga; he's head of education) is one of the people I consulted when I wrote about it. The one I quoted is a physicist at NIST, Ted Doiran.
>

He is holding the set in a cloth (white) glove - on the 2" Ceramic - mid
length in weight I suppose. Thumb finger with two more fingers holding
the weight. - I'm looking at my pdf version not the 3-ring manual in the
shelf.

I missed the class, but got the book. I was asked to attend to IBM's
needs for a month in Bordeaux France. Rough duty. Gained weight.
9-4pm. Hour lunch. When I wasn't there, they ate lunch with their
children if they had any. IBM Cafe was something else. French cooks
and good food, wine and bread.

Martin

[edhun...@gmail.com]

On Sunday, December 4, 2016 at 10:21:40 PM UTC-5, Martin Eastburn wrote:
> On 12/4/2016 2:34 AM, edhun...@gmail.com wrote:
> > On Saturday, December 3, 2016 at 11:03:57 PM UTC-5, Martin Eastburn wrote:
> >> In my handbook of Metrology Version 1.1 By Nobuo Suga Mitutoyo Institute
> >> of Metrology - America
> >>
> >> Metal to ceramic is a no-no. Keep like kinds together. However
> >> it is done...
> >>
> >> On page 3-10 or pp 44 - steel gage block wringing to optical parallel,
> >> wring to two Ceramic Gage Blocks (2" and 1") - then two more steel gage
> >> blocks wringing on the end.- 5 surfaces at once.
> >>
> >> "High degree of flatness as well as surface "roughness" are required to
> >> achieve this Phenomenon called winging."
> >>
> >> "The winging layer between blocks are in the range of 25 nano-meter.
> >> or for the imperial - .000001 in."
> >>
> >> Martin
> >
> > If that photo showing the stack of mixed gage blocks is the one I think it is, it's one I shot -- of Suga's hand. <g>
> >
> > Mitutoyo's gage-block expert (not Suga; he's head of education) is one of the people I consulted when I wrote about it. The one I quoted is a physicist at NIST, Ted Doiran.
> >
> He is holding the set in a cloth (white) glove - on the 2" Ceramic - mid
> length in weight I suppose. Thumb finger with two more fingers holding
> the weight. - I'm looking at my pdf version not the 3-ring manual in the
> shelf.

I don't remember the glove. It must be a different photo.

I was supposed to write that book, BTW, but I got pretty sick and was out of commission for a long time. So Suga did it himself. He's good at English when he talks, and is an extremely smart gentleman, but he needs an editor when he writes.

>
> I missed the class, but got the book. I was asked to attend to IBM's
> needs for a month in Bordeaux France. Rough duty. Gained weight.
> 9-4pm. Hour lunch. When I wasn't there, they ate lunch with their
> children if they had any. IBM Cafe was something else. French cooks
> and good food, wine and bread.
>
> Martin

Gee, it must have been a struggle. <g>

--
Ed Huntress

[Martin Eastburn]

I suspect it was a QA issue - fingerprints kill good gage blocks.
:-)

At work I used to work 16 hours a day partly due to traffic woes. But
my customers in Europe and the East coast could send me email
(We started Sinet) and I'd get it when I got in. Process it during the
day and shoot them a reply with data. They walk in and get their reply.

I was the go to guy for the two Big "I" companies. The French had
me teach Texan along the way.

Martin

[mog...@hotmail.com]

I remember when I was in southwest Germany, I've never been anywhere else where there was such a strong smell of bread baking so often. I'd have loved to invite myself over to whichever house it was.

[dca...@krl.org]

On Sunday, December 4, 2016 at 12:36:20 PM UTC-5, edhun...@gmail.com wrote:

> That is a really good explanation. I might add one detail: it's not clear to me which types of lubrication are involved, but some lubricants not formulated for cutting (such as motor oil) can cause a cutting edge to skate over the work if the machine isn't sufficiently rigid or if the cut isn't sufficiently aggressive. This is why I cringe when people discuss cooking up their own brews of cutting oil, including the use of ATF.
>

> --
> Ed Huntress

Cringe away! For God's sake., do not under any circumstances actually
try using ATF.

Dan

[edhun...@gmail.com]

I don't use it on my lathe for the same reason I don't put sulfated cutting oil in my car's transmission.

--
Ed Huntress

[dca...@krl.org]

On Thursday, December 8, 2016 at 7:36:16 PM UTC-5, edhun...@gmail.com wrote:


> I don't use it on my lathe for the same reason I don't put sulfated cutting oil in my car's transmission.
>
> --
> Ed Huntress

Ah. Tradition.

Dan

[edhun...@gmail.com]

Common sense.

--
Ed Huntress

[dca...@krl.org]

On Friday, December 9, 2016 at 9:04:58 AM UTC-5, edhun...@gmail.com wrote:

> > Ah. Tradition.
> >
> > Dan
>
> Common sense.
>
> --
> Ed Huntress

If it were common sense, you would have tried ATF as a cutting lube and decided on how it performs. It is not as if trying ATF is ooing to contaminate the lathe. No it is tradition in your case.

Dan

[edhun...@gmail.com]

Why don't you just piss on it, Dan, and see how that performs?

And why buy ATF for an experiment when I already have real cutting oil that works?

--
Ed Huntress

[dca...@krl.org]

On Friday, December 9, 2016 at 2:19:02 PM UTC-5, edhun...@gmail.com wrote:

> Why don't you just piss on it, Dan, and see how that performs?

ATF is a low viscosity lubricant good for high pressures and has good antirust qualities. _Pretty much the properties needed for a cutting lubricant. And since it is used in millions of automobiles and sold almost everywhere. So it is inexpensive.

Piss on the other hand is cheaper, but is not good as a high pressure lubricant. And it has no antirust properties. As a cutting fluid it would work for removing heat, but water is cheaper and is better as far as rust is concerned.

>
> And why buy ATF for an experiment when I already have real cutting oil that works?
>

But since you have not used ATF as a cutting libricant, I contend you are not qualified to tell others that that it is not good. So keep using your real cutting oil, but why don't you quit saying it is not good for home shop machining. You admit you do not have any experience with it.

Dan

> --
> Ed Huntress

[edhun...@gmail.com]

I know how experts have reacted when I mentioned that some home-shop machinists use it. It gets an eye-roll.

ATF is a very complex formulation, formulated to do just about the opposite of what you want in a cutting oil. It has to maintain band friction, and the high-pressure function is just about the opposite of what you want. You want high pressure tolerance with HIGH friction under high pressure, which is what you get, more or less, with sulfur and other additives. Otherwise, the tool can skate.

You don't know what you're talking about. It's almost certain that you've never done the instrumented tests on friction, tool load, tool wear, finish, and other tests that the real experts do.

So go use your rat-piss or whatever. It's your lathe. Just don't try to tell us that you have a clue.

--
Ed Huntress

[dca...@krl.org]

But if you have not used it , you are unqualified to comment.

I would not recommend using ATF in a commercial shop. A commercial shop is probably using soluble oil which is mostly water.

Dan

[edhun...@gmail.com]

And you have done no engineering-quality comparison, so you might as well be using tomato soup.

>
> I would not recommend using ATF in a commercial shop.

We're all happy to hear that, Dan.

> A commercial shop is probably using soluble oil which is mostly water.
>
> Dan

As speeds go up and the machining environment becomes more demanding, you go through several performance realms that demand different lubricating/cooling fluids. At the high end, you neither need lubrication nor want cooling. Very high speed hard machining usually is done dry.

--
Ed Huntress