A local place has these on sale; I could easily mount it on the grinder.

This for small bits - 7x10 lathe.

A local place has these on sale; I could easily mount it on the grinder.

This for small bits - 7x10 lathe.


diamond is the choice for sharpening carbide. If you're talking about
brazed bits, keep in mind that the soft steel underneath EATS diamond. I
have two wheels on my baldor, the green wheel is set to 8 degrees for
ruffing and then the diamond wheel is set to 5 degrees for finish sharpen of
the carbide.

Karl

"jtaylor" wrote in message
...
A local place has these on sale; I could easily mount it on the grinder.

This for small bits - 7x10 lathe.

The problem with using that type wheel is the limited surface available for
doing your grinding, and is likely to yield poor results under normal
circumstances. The typical diamond wheel that's applied for sharpening
carbide lathe tools has the diamond on the side, in a broad area, usually
about 3/4" wide.

Pay attention to the caution already offered on grinding steel. Diamond is
destroyed by steel when applied at high speed----it actually is dissolved
into the steel, cutting its useful life very short by dulling it until it
doesn't cut well. Relieving it on an aluminum oxide wheel at a greater
angle is the typical method of avoiding contact with a diamond wheel. Using
a green wheel presents the same problems that diamond does---it, too, is
soluble in steel. It's silicon carbide.

Unlike HSS, free hand grinding of carbide is not in your best interest.
It's done best with an adjustable tool rest, so you can set the proper
relief angles.

Harold

Pay attention to the caution already offered on grinding steel. Diamond is
destroyed by steel when applied at high speed----it actually is dissolved
into the steel, cutting its useful life very short by dulling it until it
doesn't cut well. Relieving it on an aluminum oxide wheel at a greater
angle is the typical method of avoiding contact with a diamond wheel.
Using
a green wheel presents the same problems that diamond does---it, too, is
soluble in steel. It's silicon carbide.

Harold,

I've gotten fair life out of the green wheel for ruffing brazed carbide bits
on the the Baldor grinder. But I'm sure I'll have to replace it sometime.
I've not seen aluminum oxide Baldor wheels, are they made? Will aluminum
oxide cut carbide at all? I always thought carbide just bounces off.

I've always used the green wheel cause I don't know any better.

Karl

jtaylor writes:

A local place has these on sale; I could easily mount it on the grinder.

I've wanted to try that with my MK-101 wet tile cutter. I think side-
loading a circular saw blade might be a problem. But they certainly make a
smooth cut on the hardest stone, so I would think the carbide is a
possibility.

"Karl Townsend" remove .NOT to reply wrote
in message ink.net...
Pay attention to the caution already offered on grinding steel. Diamond
is
destroyed by steel when applied at high speed----it actually is
dissolved
into the steel, cutting its useful life very short by dulling it until
it
doesn't cut well. Relieving it on an aluminum oxide wheel at a
greater
angle is the typical method of avoiding contact with a diamond wheel.
Using
a green wheel presents the same problems that diamond does---it, too, is
soluble in steel. It's silicon carbide.

Harold,

I've gotten fair life out of the green wheel for ruffing brazed carbide
bits
on the the Baldor grinder. But I'm sure I'll have to replace it sometime.
I've not seen aluminum oxide Baldor wheels, are they made?

I trust you're talking about the steel backed wheels, on which you use the
face to grind, not the periphery. Yes, they're available, but are not
cheap. If you intend to stay with the green wheels for carbide (I don't
recommend it, and if you once try diamond you won't either) it's easy enough
to go to an aluminum oxide wheel on a different spindle to grind the steel
back to avoid contact. You'd do that with a diamond wheel, exactly the same
way. That's what I've always done with diamond wheels, or when I had no
choice but to use the green wheels.


Will aluminum
oxide cut carbide at all? I always thought carbide just bounces off.

You've pretty much got it. Aluminum oxide is a lot softer than silicon
carbide, but grinds steel far better because it *doesn't* dissolve into the
steel the way silicon carbide does. Carbide is slowly ground by aluminum
oxide, but at the expense of dulling the grain prematurely, much the same
way steel does silicon carbide, but for different reasons.

I've always used the green wheel cause I don't know any better.

In the scheme of things, it doesn't make a big difference, Karl. If you
are the typical home shop type that occasionally sharpens some brazed
carbide, the worst case scenario is you'll buy one extra wheel in your life
time because you waste a little when you grind steel. Because green wheels
are bonded softly, they are quite friable and break down quickly, which is
the chief reason they work as well as they do when grinding carbide. Keep
in mind that the silicon carbide is *not* any softer, just the bond. If
they didn't break down, the dulling would quickly bring the grinding to a
halt. When you grind on steel, although it's quite soft, the grains
dull very quickly and are shed, exposing new, sharp grains. That's where
you experience the loss. As I said, for casual use, no big deal. The
only real issue would be a health one, which is silicosis. Breathing the
dust is not a good idea, and you make plenty of it when you shed the wheel.

Harold

On Wed, 09 Feb 2005 19:48:29 -0600, Richard J Kinch
wrote:

jtaylor writes:

A local place has these on sale; I could easily mount it on the grinder.

I've wanted to try that with my MK-101 wet tile cutter. I think side-
loading a circular saw blade might be a problem. But they certainly make a
smooth cut on the hardest stone, so I would think the carbide is a
possibility.

I have one of those MK saws sure beats lugging in a heavy wet saw.
Not long ago I customized it to cut 16" tile , was just .5-.7" short.
It took awhile to figure out how to do it and at the same time bitchen
at the designer. Harold uses diamond , all I know is that I won't cut
steel with any of my blades. I find the oldest beat up one to
customize trowels (seems to be about the only thing that will go
through them) cause they go down hill fast when I go back to tile.

I had to laugh at myself the time I made a segmented blade out of one
with another ! Still have that one. Never did try sharpening metal
cutting tools with them cause even rebar screws them up around me.
Matter of fact the price at least doubles if I see metal sparks while
cutting concrete just to calm me down when I buy new ones. My
father-in-law thinks it's cool to cut steel with them and I just
cringe and shut up.

"Sunworshipper" wrote in message
...
On Wed, 09 Feb 2005 19:48:29 -0600, Richard J Kinch
wrote:

jtaylor writes:

A local place has these on sale; I could easily mount it on the
grinder.

I've wanted to try that with my MK-101 wet tile cutter. I think side-
loading a circular saw blade might be a problem. But they certainly make
a
smooth cut on the hardest stone, so I would think the carbide is a
possibility.

I have one of those MK saws sure beats lugging in a heavy wet saw.
Not long ago I customized it to cut 16" tile , was just .5-.7" short.
It took awhile to figure out how to do it and at the same time bitchen
at the designer. Harold uses diamond , all I know is that I won't cut
steel with any of my blades. I find the oldest beat up one to
customize trowels (seems to be about the only thing that will go
through them) cause they go down hill fast when I go back to tile.

The fact that diamond dissolves into steel, destroying the diamond, is well
known, and published in literature from Norton. Research on the subject was
conducted back in the early 50's, as I recall. Running diamond on steel at
elevated temperature, such as high speed grinding, is death on diamonds.
You're smart to avoid doing so.


I had to laugh at myself the time I made a segmented blade out of one
with another ! Still have that one. Never did try sharpening metal
cutting tools with them cause even rebar screws them up around me.

And now you know why!

Harold

On Fri, 11 Feb 2005 12:11:06 -0800, "Harold and Susan Vordos"
wrote:


The fact that diamond dissolves into steel, destroying the diamond, is well
known, and published in literature from Norton. Research on the subject was
conducted back in the early 50's, as I recall. Running diamond on steel at
elevated temperature, such as high speed grinding, is death on diamonds.
You're smart to avoid doing so.



You _can_ cut steel with diamond. You just have to run it so slow that it
doesn't heat up. The down side of this is that it's slow :-(


Mark Rand
RTFM

"Mark Rand" wrote in message
...
On Fri, 11 Feb 2005 12:11:06 -0800, "Harold and Susan Vordos"

wrote:


The fact that diamond dissolves into steel, destroying the diamond, is
well
known, and published in literature from Norton. Research on the subject
was
conducted back in the early 50's, as I recall. Running diamond on steel
at
elevated temperature, such as high speed grinding, is death on diamonds.
You're smart to avoid doing so.



You _can_ cut steel with diamond. You just have to run it so slow that it
doesn't heat up. The down side of this is that it's slow :-(


Mark Rand
RTFM

Didn't I say that?

Harold

I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?

Martin

Harold and Susan Vordos wrote:

"Sunworshipper" wrote in message
...

On Wed, 09 Feb 2005 19:48:29 -0600, Richard J Kinch
wrote:


jtaylor writes:


A local place has these on sale; I could easily mount it on the

grinder.

I've wanted to try that with my MK-101 wet tile cutter. I think side-
loading a circular saw blade might be a problem. But they certainly make

a

smooth cut on the hardest stone, so I would think the carbide is a
possibility.

I have one of those MK saws sure beats lugging in a heavy wet saw.
Not long ago I customized it to cut 16" tile , was just .5-.7" short.
It took awhile to figure out how to do it and at the same time bitchen
at the designer. Harold uses diamond , all I know is that I won't cut
steel with any of my blades. I find the oldest beat up one to
customize trowels (seems to be about the only thing that will go
through them) cause they go down hill fast when I go back to tile.


The fact that diamond dissolves into steel, destroying the diamond, is well
known, and published in literature from Norton. Research on the subject was
conducted back in the early 50's, as I recall. Running diamond on steel at
elevated temperature, such as high speed grinding, is death on diamonds.
You're smart to avoid doing so.


I had to laugh at myself the time I made a segmented blade out of one
with another ! Still have that one. Never did try sharpening metal
cutting tools with them cause even rebar screws them up around me.


And now you know why!

Harold




--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

"Martin H. Eastburn" wrote in message
t...

I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?

The cutting part of diamond tools is diamond (natural industrial diamond or
vapor-deposited diamond coatings, or, in a couple of rare cases,
vapor-deposited diamond stripped from a substrate and diced into thin
braze-in tips), or diamond bonded in a press-and-sinter operation with one
of several binders (PCD tips). There is no steel involved in the actual
cutting tip.

As someone said, diamond combines chemically with steel or iron much quicker
at high temperatures. It's a very expensive way to carburize a piece of
steel. g

It works Ok for cool lapping, badly for turning or milling, and it's a big
loser in grinding. Still, it has its uses for cutting ferrous metals. You
just have to be aware that you're in for an expensive proposition because of
the chemical action.

A couple of years ago I talked to a scientist at GE materials and I was
surprised to hear him say that cubic boron nitride (CBN, or PCBN) also
combines with steel at high temperatures, but at a much slower rate than
diamond. Chemistry is one of my weak areas so I can't comment but to pass on
what I read or hear.

Anyway, CBN lives as a tool material because of the problem of diamond
combining with ferrous metals in common metalcutting operations, simply
adding to the carbon content of the metal being cut.

--
Ed Huntress

"Martin H. Eastburn" wrote in message
t...

I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?

Martin

They may do that, but are they recommended for the application? Dunno.
I've never used diamond turning or milling tools. If so, do they recommend
specific speeds, to keep the temperature down? That's the critical point.

I'm not convinced I'm the right person to answer the degree of transfer, but
for diamonds that rely on sharp corners to do their work, it takes very
little to change them appreciably. Iron has an affinity for carbon, and it
isn't proud where it gets it. Up to the point of saturation, so long as
the temperature permits transfer, it will absorb it. That tells me that
prolonged contact at high temperature, iron could literally absorb a
complete diamond.

It's not a heat thing alone, nor is it an iron thing. Diamonds will
withstand soldering (re-tipping prongs, for example) with no ill affects,
and they can withstand a constant dressing of aluminum oxide or silicon
carbide wheels, even large ones such as are found on centerless grinders.
They are often 24" in diameter and 8" or more wide. Heat isn't a problem,
but combined with iron, it quickly becomes one. That's about the extent of
what I know, and from experience, I know that contacting diamond wheels with
iron (steel) is a mistake. The typical diamond wheel feels as if it's been
greased once steel has been applied. Sorry I'm not more help.

Harold

"Harold and Susan Vordos" wrote in message
...

"jtaylor" wrote in message
...
A local place has these on sale; I could easily mount it on the grinder.

This for small bits - 7x10 lathe.

The problem with using that type wheel is the limited surface available
for
doing your grinding, and is likely to yield poor results under normal
circumstances. The typical diamond wheel that's applied for sharpening
carbide lathe tools has the diamond on the side, in a broad area, usually
about 3/4" wide.

Pay attention to the caution already offered on grinding steel. Diamond is
destroyed by steel when applied at high speed----it actually is dissolved
into the steel, cutting its useful life very short by dulling it until it
doesn't cut well. Relieving it on an aluminum oxide wheel at a greater
angle is the typical method of avoiding contact with a diamond wheel.
Using
a green wheel presents the same problems that diamond does---it, too, is
soluble in steel. It's silicon carbide.

So you can't grind HSS on a green wheel?

"ATP*" wrote in message
...

"Harold and Susan Vordos" wrote in message
...

"jtaylor" wrote in message
...
A local place has these on sale; I could easily mount it on the
grinder.

This for small bits - 7x10 lathe.

The problem with using that type wheel is the limited surface available
for
doing your grinding, and is likely to yield poor results under normal
circumstances. The typical diamond wheel that's applied for
sharpening
carbide lathe tools has the diamond on the side, in a broad area,
usually
about 3/4" wide.

Pay attention to the caution already offered on grinding steel. Diamond
is
destroyed by steel when applied at high speed----it actually is
dissolved
into the steel, cutting its useful life very short by dulling it until
it
doesn't cut well. Relieving it on an aluminum oxide wheel at a
greater
angle is the typical method of avoiding contact with a diamond wheel.
Using
a green wheel presents the same problems that diamond does---it, too, is
soluble in steel. It's silicon carbide.

So you can't grind HSS on a green wheel?

Not with great success. The green wheel will break down very rapidly due to
dulling of the abrasive by dissolution. Being softly bonded, it readily
sloughs off to expose new bits of abrasive, which, in turn, dull quickly.
By contrast, you can use an aluminum oxide wheel that is softer, but bonded
much harder, and grind without any loss of wheel because the aluminum oxide
doesn't dissolve into the steel. It stays sharp much longer, so it has no
need to slough off, thus a harder bonded wheel. That's the reason tool and
cutter grinder wheels (where cutting tools are made from HSS) are made from
aluminum oxide instead of silicon carbide.

It pays to match the grinding media to the work at hand. You not only get a
better quality job, but the wheels hold up much better and work faster.

Harold

Harold and Susan Vordos wrote:
"ATP*" wrote in message
...

"Harold and Susan Vordos" wrote in message
...

"jtaylor" wrote in message
...

A local place has these on sale; I could easily mount it on the

grinder.

This for small bits - 7x10 lathe.


The problem with using that type wheel is the limited surface available
for
doing your grinding, and is likely to yield poor results under normal
circumstances. The typical diamond wheel that's applied for

sharpening

carbide lathe tools has the diamond on the side, in a broad area,

usually

about 3/4" wide.

Pay attention to the caution already offered on grinding steel. Diamond

is

destroyed by steel when applied at high speed----it actually is

dissolved

into the steel, cutting its useful life very short by dulling it until

it

doesn't cut well. Relieving it on an aluminum oxide wheel at a

greater

angle is the typical method of avoiding contact with a diamond wheel.
Using
a green wheel presents the same problems that diamond does---it, too, is
soluble in steel. It's silicon carbide.


So you can't grind HSS on a green wheel?


Not with great success. The green wheel will break down very rapidly due to
dulling of the abrasive by dissolution. Being softly bonded, it readily
sloughs off to expose new bits of abrasive, which, in turn, dull quickly.
By contrast, you can use an aluminum oxide wheel that is softer, but bonded
much harder, and grind without any loss of wheel because the aluminum oxide
doesn't dissolve into the steel. It stays sharp much longer, so it has no
need to slough off, thus a harder bonded wheel. That's the reason tool and
cutter grinder wheels (where cutting tools are made from HSS) are made from
aluminum oxide instead of silicon carbide.

It pays to match the grinding media to the work at hand. You not only get a
better quality job, but the wheels hold up much better and work faster.

Harold


I would like some input on Drill-Doctor using a diamond wheel to sharpen

HSS drill bits. It works OK.

Ed Huntress wrote:

"Martin H. Eastburn" wrote in message
t...

I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?


The cutting part of diamond tools is diamond (natural industrial diamond or
vapor-deposited diamond coatings, or, in a couple of rare cases,
vapor-deposited diamond stripped from a substrate and diced into thin
braze-in tips), or diamond bonded in a press-and-sinter operation with one
of several binders (PCD tips). There is no steel involved in the actual
cutting tip.

As someone said, diamond combines chemically with steel or iron much quicker
at high temperatures. It's a very expensive way to carburize a piece of
steel. g

It works Ok for cool lapping, badly for turning or milling, and it's a big
loser in grinding. Still, it has its uses for cutting ferrous metals. You
just have to be aware that you're in for an expensive proposition because of
the chemical action.

snip
--
Ed Huntress



Remember the diamond is mounted on a steel or is it Nickel - hum - ring.
The ring is a heat conductor to the main shaft that is cooled. The diamond is
the most efficient conductor of heat - Sapphire is next. So the diamond that gets
hot is rapidly cooled as it is turned at very high speed. In general, cooling
is best at all times, but there hasn't been a scram issue on replacements for the unit
from what I can tell it is still for sale. I have one, and have ground both HSS and
simple steel (if there is one) and even ground a carbide tip drill. My spare
wheel bought at the time of sale is still in the machinist chest where it was saved.
I don't use it often, I use it as a pre-grinder or drill saver. Releaf behind
the grinding edge is not relieved. I save the drill - might split grind it and then
hand grind the fine touches as needed.

The drill Dr. isn't perfect but gives me a well pointed (centered and maybe split) so
my grinder time is for touch up not heavy grinding a chip.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

Harold and Susan Vordos wrote:

"Martin H. Eastburn" wrote in message
t...

I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?

Martin


They may do that, but are they recommended for the application? Dunno.
I've never used diamond turning or milling tools. If so, do they recommend
specific speeds, to keep the temperature down? That's the critical point.

I'm not convinced I'm the right person to answer the degree of transfer, but
for diamonds that rely on sharp corners to do their work, it takes very
little to change them appreciably. Iron has an affinity for carbon, and it
isn't proud where it gets it. Up to the point of saturation, so long as
the temperature permits transfer, it will absorb it. That tells me that
prolonged contact at high temperature, iron could literally absorb a
complete diamond.

It's not a heat thing alone, nor is it an iron thing. Diamonds will
withstand soldering (re-tipping prongs, for example) with no ill affects,
and they can withstand a constant dressing of aluminum oxide or silicon
carbide wheels, even large ones such as are found on centerless grinders.
They are often 24" in diameter and 8" or more wide. Heat isn't a problem,
but combined with iron, it quickly becomes one. That's about the extent of
what I know, and from experience, I know that contacting diamond wheels with
iron (steel) is a mistake. The typical diamond wheel feels as if it's been
greased once steel has been applied. Sorry I'm not more help.

Harold


Diamond is typically grinding and sawing. Sapphire is and Diamond I believe used
in exotic sharp edge cutting of plastics and glass. Typically both fracture
under load if not supported.

Since the diamond is best in conduction - your hand on the far side of a thin diamond
window would feel almost all of the heat on the other side - so when the tool tip gets hot,
it conducts to the base metal - steel and flows off - cooling the diamond.

Continuous heat addition (at one spot ) (as with a flame or arc) would, but a turning
tool and the conduction prevents this. Also the typical use involves a flood of water
based coolant.

Martin

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

"Martin H. Eastburn" wrote in message
...
Harold and Susan Vordos wrote:

"Martin H. Eastburn" wrote in message
t...

I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?

Martin


They may do that, but are they recommended for the application? Dunno.
I've never used diamond turning or milling tools. If so, do they
recommend
specific speeds, to keep the temperature down? That's the critical
point.

I'm not convinced I'm the right person to answer the degree of transfer,
but
for diamonds that rely on sharp corners to do their work, it takes very
little to change them appreciably. Iron has an affinity for carbon,
and it
isn't proud where it gets it. Up to the point of saturation, so long
as
the temperature permits transfer, it will absorb it. That tells me
that
prolonged contact at high temperature, iron could literally absorb a
complete diamond.

It's not a heat thing alone, nor is it an iron thing. Diamonds will
withstand soldering (re-tipping prongs, for example) with no ill
affects,
and they can withstand a constant dressing of aluminum oxide or silicon
carbide wheels, even large ones such as are found on centerless
grinders.
They are often 24" in diameter and 8" or more wide. Heat isn't a
problem,
but combined with iron, it quickly becomes one. That's about the
extent of
what I know, and from experience, I know that contacting diamond wheels
with
iron (steel) is a mistake. The typical diamond wheel feels as if it's
been
greased once steel has been applied. Sorry I'm not more help.

Harold


Diamond is typically grinding and sawing. Sapphire is and Diamond I
believe used
in exotic sharp edge cutting of plastics and glass. Typically both
fracture
under load if not supported.

Since the diamond is best in conduction - your hand on the far side of a
thin diamond
window would feel almost all of the heat on the other side - so when the
tool tip gets hot,
it conducts to the base metal - steel and flows off - cooling the diamond.

Continuous heat addition (at one spot ) (as with a flame or arc) would,
but a turning
tool and the conduction prevents this. Also the typical use involves a
flood of water
based coolant.

Martin

I'm not sure what you're saying here, Martin, but diamond turning and
milling cutters are not used on ferrous metals except in very rare
situations. They just don't last, for the reasons Howard has explained.

In production, diamond is use primarily on high-silicon aluminum. Other uses
include composites, plastics, glass, and other non-ferrous metals.

The development that made polycrystalline synthetic diamond a near-necessity
in production was the use of very high-silicon (hypereutectic) aluminum
casting alloys in automotive applications. Another one of the early users
was Mercury Marine, who used it for machining their hypereutectic outboard
motor blocks. OMC soon followed suit.

--
Ed Huntress

Ed Huntress wrote:

"Martin H. Eastburn" wrote in message
...

Harold and Susan Vordos wrote:


"Martin H. Eastburn" wrote in message
.net...


I think we need to think about this a little.

Diamond cutting tools are steel based and cut steel HSS and carbide
drills and mills. Perhaps there is transference, but not all that
much ?

Martin


They may do that, but are they recommended for the application? Dunno.
I've never used diamond turning or milling tools. If so, do they

recommend

specific speeds, to keep the temperature down? That's the critical

point.

I'm not convinced I'm the right person to answer the degree of transfer,

but

for diamonds that rely on sharp corners to do their work, it takes very
little to change them appreciably. Iron has an affinity for carbon,

and it

isn't proud where it gets it. Up to the point of saturation, so long

as

the temperature permits transfer, it will absorb it. That tells me

that

prolonged contact at high temperature, iron could literally absorb a
complete diamond.

It's not a heat thing alone, nor is it an iron thing. Diamonds will
withstand soldering (re-tipping prongs, for example) with no ill

affects,

and they can withstand a constant dressing of aluminum oxide or silicon
carbide wheels, even large ones such as are found on centerless

grinders.

They are often 24" in diameter and 8" or more wide. Heat isn't a

problem,

but combined with iron, it quickly becomes one. That's about the

extent of

what I know, and from experience, I know that contacting diamond wheels

with

iron (steel) is a mistake. The typical diamond wheel feels as if it's

been

greased once steel has been applied. Sorry I'm not more help.

Harold



Diamond is typically grinding and sawing. Sapphire is and Diamond I

believe used

in exotic sharp edge cutting of plastics and glass. Typically both

fracture

under load if not supported.

Since the diamond is best in conduction - your hand on the far side of a

thin diamond

window would feel almost all of the heat on the other side - so when the

tool tip gets hot,

it conducts to the base metal - steel and flows off - cooling the diamond.

Continuous heat addition (at one spot ) (as with a flame or arc) would,

but a turning

tool and the conduction prevents this. Also the typical use involves a

flood of water

based coolant.

Martin


I'm not sure what you're saying here, Martin, but diamond turning and
milling cutters are not used on ferrous metals except in very rare
situations. They just don't last, for the reasons Howard has explained.

In production, diamond is use primarily on high-silicon aluminum. Other uses
include composites, plastics, glass, and other non-ferrous metals.

The development that made polycrystalline synthetic diamond a near-necessity
in production was the use of very high-silicon (hypereutectic) aluminum
casting alloys in automotive applications. Another one of the early users
was Mercury Marine, who used it for machining their hypereutectic outboard
motor blocks. OMC soon followed suit.

--
Ed Huntress


Ed - I generally agree. But I feel the panic is a bit high.

A diamond on a metal base that is spinning contacts the work for a very very short period
of time. This assumes the tool is spinning and the diamond isn't massive...

I'm assuming a 'point' of fine atomic level that diamond can do. It is the touching / grinding
on a fine point. [ remember the Garnet sanding sheets that shatter as they impact and stay sharp ]
diamond is tougher and stands up to higher pressures.

The 'nano'-second it touches the work it will heat up but starts to cool down as the cutting arc
is swept. The diamond wicks the heat (being the best conductor - far better than metals) to the
work base metal the diamond is loaded into. Which gets hot. (a little anyway).

If coolant is supplied as in mills this would help.

Normally diamond is to expensive to use in a normal work area, other materials have been developed.
Even special process of near zero degree work has been developed for some applications.

Saw blades have diamond pressed into slots on the circumference. These slice through rock and cements...
I have sliced through tons of material. The diamond doesn't absorb into the host material (the tool)
but I suspect the very highest temps are only at the tip where atoms are stolen.

Is it simply a matter of cost ? - the carbon is absorbed a little and the tool becomes used up?

Maybe the data is simply old economics. Diamond drill heads bore through iron cobalt deposits and
other iron rich layers for many years in well drilling. So maybe research needs to look at this
again with a different point of view.

Martin

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

"Martin H. Eastburn" wrote in message
. ..
Ed Huntress wrote:

I'm not sure what you're saying here, Martin, but diamond turning and
milling cutters are not used on ferrous metals except in very rare
situations. They just don't last, for the reasons Howard has explained.

In production, diamond is use primarily on high-silicon aluminum. Other
uses
include composites, plastics, glass, and other non-ferrous metals.

The development that made polycrystalline synthetic diamond a
near-necessity
in production was the use of very high-silicon (hypereutectic) aluminum
casting alloys in automotive applications. Another one of the early
users
was Mercury Marine, who used it for machining their hypereutectic
outboard
motor blocks. OMC soon followed suit.

--
Ed Huntress


Ed - I generally agree. But I feel the panic is a bit high.

A diamond on a metal base that is spinning contacts the work for a very
very short period
of time. This assumes the tool is spinning and the diamond isn't
massive...

I'm assuming a 'point' of fine atomic level that diamond can do. It is
the touching / grinding
on a fine point. [ remember the Garnet sanding sheets that shatter as they
impact and stay sharp ]
diamond is tougher and stands up to higher pressures.

The 'nano'-second it touches the work it will heat up but starts to cool
down as the cutting arc
is swept. The diamond wicks the heat (being the best conductor - far
better than metals) to the
work base metal the diamond is loaded into. Which gets hot. (a little
anyway).

If coolant is supplied as in mills this would help.

Normally diamond is to expensive to use in a normal work area, other
materials have been developed.
Even special process of near zero degree work has been developed for some
applications.

Saw blades have diamond pressed into slots on the circumference. These
slice through rock and cements...
I have sliced through tons of material. The diamond doesn't absorb into
the host material (the tool)
but I suspect the very highest temps are only at the tip where atoms are
stolen.

Is it simply a matter of cost ? - the carbon is absorbed a little and the
tool becomes used up?

Maybe the data is simply old economics. Diamond drill heads bore through
iron cobalt deposits and
other iron rich layers for many years in well drilling. So maybe research
needs to look at this
again with a different point of view.

Martin

Well, yes, it's economics. In turning and milling ferrous metals, the costs
of using diamond tools can be worked out very neatly from wear-life data
that was compiled decades ago. Using diamond cutting tools in chip-making
applications on iron and steel is very expensive business, and the amount of
it that is due to chemical carbon loss has been quantified. I haven't seen
the data since around 1979 or so, when GE was touting its then-new CBN, but
it's out there.

There are some places where it's been used on steel. I think it was
Pneumo-Precision that was using diamond tools for steel on one of their
optical-grade lathes (built on granite bases) back in the late '70s and
early '80s. The applications were optical or optical-grade turning.

It's not that it doesn't work, and it's true that there are some rare
situations in which it's the way to go. But not in general.

Grinding, honing and lapping are another matter. The same principles apply
but the dynamics and the economics are different. Again, I haven't kept up
with this. The last thing I remember was some data from Sunnen on their
plated-diamond, one-pass honing tools that came out in the early '90s. It's
a bit more complex than the situation faced with chip-making tools.

--
Ed Huntress

"Martin H. Eastburn" wrote in message
. ..
snip----


Saw blades have diamond pressed into slots on the circumference. These
slice through rock and cements...
I have sliced through tons of material. The diamond doesn't absorb into
the host material (the tool)
but I suspect the very highest temps are only at the tip where atoms are
stolen.

The host material isn't where the diamonds are mounted. There's usually an
alloy that becomes the bonding agent, and it doesn't have an affinity for
carbon. There is no transfer of carbon for that reason.


Is it simply a matter of cost ? - the carbon is absorbed a little and the
tool becomes used up?

With grinding wheels that are dressed by diamond, the diamond gets dull and
ceases to cut easily with prolonged use. If you're familiar with dressing
grinding wheels, you understand why the typical diamond dressing tool mounts
the diamond at an angle instead of at right angles. That way, all you have
to do is rotate the diamond slightly to present a sharp corner of the
diamond to the wheel so it cuts cleanly instead of burnishing the wheel.
It would be much the same with diamond grinding wheels. The slightest
dulling by absorption renders the diamond far less affective. The diamond
may not be used up, but it gets dulled to the point where it takes
considerable pressure to get it to cut, and you risk tearing the diamond out
of the matrix as a result.

Maybe the data is simply old economics. Diamond drill heads bore through
iron cobalt deposits and
other iron rich layers for many years in well drilling. So maybe research
needs to look at this
again with a different point of view.

Martin

Martin, I think you're overlooking the fact that well drilling takes place
at much lower speed, so low that the critical temperatures are never
approached.

I'm not convinced anyone is suggesting diamond can't be used for cutting
ferrous metals, but there are inherent hazards involved, one of which is the
shortened life of the tool, especially if it's at accelerated speeds. The
lesson that's important for the home shop types to learn is that diamond
grinding wheels should never make contact with iron or iron alloys at high
speeds in order to preserve the diamond. The slightest contact affects a
wheels ability to cut. So much so that the wheel often requires a dressing
in order to restore a wheels ability to cut freely. I'm sure wheel loading
is a part of the reason, but dressing the wheel takes life out of it, so
it's a good idea to minimize dressing. You can do that by avoiding grinding
steel.

Harold

In article , Harold and Susan Vordos says...

The host material isn't where the diamonds are mounted. There's usually an
alloy that becomes the bonding agent, and it doesn't have an affinity for
carbon. There is no transfer of carbon for that reason.

I've actually had occasion to talk to the Kennametals folks who
make things like cutting tools. They also produce fine (micron
particle size or thereabouts) bronze powder. This is an alloy
of copper and tin which is specifically used as a sintering
binder for that application - bonding diamond particles to
steel tooling.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

In article , Martin H. Eastburn
says...

Maybe the data is simply old economics. Diamond drill heads bore through iron
cobalt deposits and
other iron rich layers for many years in well drilling. So maybe research needs
to look at this
again with a different point of view.

I thought that drill heads are continously pumped full of drilling
mud, to carry away the cut material. Because the drills run
immersed in water-based solution I bet the chemistry is a lot
different at the lower temperatures.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

On 15 Feb 2005 05:33:16 -0800, jim rozen
wrote:

In article , Harold and Susan Vordos says...

The host material isn't where the diamonds are mounted. There's usually an
alloy that becomes the bonding agent, and it doesn't have an affinity for
carbon. There is no transfer of carbon for that reason.

I've actually had occasion to talk to the Kennametals folks who
make things like cutting tools. They also produce fine (micron
particle size or thereabouts) bronze powder. This is an alloy
of copper and tin which is specifically used as a sintering
binder for that application - bonding diamond particles to
steel tooling.

Jim

That matrix is the make or break part on diamond blades for "stone" .
If its too hard it won't cut jack **** and too soft and the blade is
down to the steel in no time.

I cringe at the thought of replacing blades to the point of testing
them on the spot. Some times they just sugar coat them and work great
for a couple of jobs and then just stop cutting at the worse possible
moment. Some won't cut the first tile. Bet I could find about 10 junk
ones around here that look like they have lots of life left. I've
often wondered if there could be a way to heat the **** out of it with
out warping it or have it fly apart on the saw to change a screwed up
job into something that will work again. Somehow weaken the matrix
that was made too hard... Hmmm maybe electricity and acid. There goes
that sharpening joke.

Harold and Susan Vordos wrote:

"Martin H. Eastburn" wrote in message
. ..
snip----



Saw blades have diamond pressed into slots on the circumference. These

slice through rock and cements...

I have sliced through tons of material. The diamond doesn't absorb into

the host material (the tool)

but I suspect the very highest temps are only at the tip where atoms are

stolen.

The host material isn't where the diamonds are mounted. There's usually an
alloy that becomes the bonding agent, and it doesn't have an affinity for
carbon. There is no transfer of carbon for that reason.


Is it simply a matter of cost ? - the carbon is absorbed a little and the

tool becomes used up?

With grinding wheels that are dressed by diamond, the diamond gets dull and
ceases to cut easily with prolonged use. If you're familiar with dressing
grinding wheels, you understand why the typical diamond dressing tool mounts
the diamond at an angle instead of at right angles. That way, all you have
to do is rotate the diamond slightly to present a sharp corner of the
diamond to the wheel so it cuts cleanly instead of burnishing the wheel.
It would be much the same with diamond grinding wheels. The slightest
dulling by absorption renders the diamond far less affective. The diamond
may not be used up, but it gets dulled to the point where it takes
considerable pressure to get it to cut, and you risk tearing the diamond out
of the matrix as a result.

Maybe the data is simply old economics. Diamond drill heads bore through

iron cobalt deposits and

other iron rich layers for many years in well drilling. So maybe research

needs to look at this

again with a different point of view.

Martin


Martin, I think you're overlooking the fact that well drilling takes place
at much lower speed, so low that the critical temperatures are never
approached.
Consider a 5000 foot hole - not the deepest by any means. That is 5000 feet
of drill pipe above it. Then the heavy drill head of three rotating cutters.
The pressure is very high. The temperature is static vary high and is boosted
by the grinding of rock with rock. Forced water or fluid is driven down the tube
through the center of the cutter (sounds like a mill doesn't it) and the now
dirty, grimy dust is forced upward around the sides of the drill tube.
I suspect the point contact temperature and pressure is extremely high. Few
really know as much of it is protected under patents. Bound to be some in
theory books and now the web.


I think the whole issue is cost of tool and what one can do without it.
There are very good replacements that can replace diamond.

Martin

I'm not convinced anyone is suggesting diamond can't be used for cutting
ferrous metals, but there are inherent hazards involved, one of which is the
shortened life of the tool, especially if it's at accelerated speeds. The
lesson that's important for the home shop types to learn is that diamond
grinding wheels should never make contact with iron or iron alloys at high
speeds in order to preserve the diamond. The slightest contact affects a
wheels ability to cut. So much so that the wheel often requires a dressing
in order to restore a wheels ability to cut freely. I'm sure wheel loading
is a part of the reason, but dressing the wheel takes life out of it, so
it's a good idea to minimize dressing. You can do that by avoiding grinding
steel.

Harold





--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

On Wed, 16 Feb 2005 06:15:25 GMT, "Martin H. Eastburn"
wrote:

approached.
Consider a 5000 foot hole - not the deepest by any means. That is 5000 feet
of drill pipe above it. Then the heavy drill head of three rotating cutters.
The pressure is very high. The temperature is static vary high and is boosted
by the grinding of rock with rock. Forced water or fluid is driven down the tube
through the center of the cutter (sounds like a mill doesn't it) and the now
dirty, grimy dust is forced upward around the sides of the drill tube.
I suspect the point contact temperature and pressure is extremely high. Few
really know as much of it is protected under patents. Bound to be some in
theory books and now the web.

Ive pulled more than one string of drill pipe to find the bit melted
down because the weight scale on the drilling line was fooked up and a
hell of a lot more weight was allowed on the bit than was proper

Gunner

Rule #35
"That which does not kill you,
has made a huge tactical error"

Kind of supprised that the drill bit doesn't include a system for regulating
the pressure on the working face of the bit.

--
Why isn't there an Ozone Hole at the NORTH Pole?

Bob May wrote:

Kind of supprised that the drill bit doesn't include a system for regulating
the pressure on the working face of the bit.

--
Why isn't there an Ozone Hole at the NORTH Pole?


Ok - think of the extreme pressure - many, many times that on the surface of earth.
Very special capacitors and transistors, resistors..... Pressure and temperature are
very high. Then add the drill temp - tough really.

I in another life years ago consulted with a small company Basin Surveys that made tools
for deep under ground measurements. Later in life, in the 80's and 90's I worked for
Schlumberger in an ATE division - but having degrees in the stuff and knowing what was
going on already, I got to talk to some of the tool designers and developers. I was
working with them on ASIC devices - to work down hole. The amount of atomic and nuclear
physics that goes on during well services is far outside the common thought. Shaped charges
nuclear bombardment and then measure the resultant return impulses. Far out stuff really,
but brings home the bacon and next well.

Then there is the comm line from tools down hole - while drilling - that measure what is
being cut and the speed of cut. It is done with a long wire - the drill stem. Ground is
the other connection. Oh this - the real time cutting and measuring - is less than 10 years
old - I mean it is really new stuff.

Martin

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder