I am thinking of taking my old anvil to work and using the surface grinder
to flatten it out.
Are old anvils heat treated, or just hardened by use?
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

If the anvil is made of steel, not cast iron, then it's face has been
hardened. "old" anvils would be plain carbon steel, somewhere between
about 1070 and 1095. Even though they were usually water quenched, the
section is so thick that the actual face hardness varied a lot. Some
are still almost hard as glass and some are so soft that the face has
actually been deformed toward the edges by the hammer blows and dished
out by use. This dishing is often called the "sweet spot" and some
blacksmiths (not me!)like it for straightening things, since when you
smack the part over the dished area it can overbend enough to exceed its
elastic limit, in a controlled sort of way.
Try filing on an edge to see how hard that one is. The horn and
everything BUT the face should be mild steel or even wrought iron if it
is old enough.
Modern anvils are often made of solid tool steel, 4140 being a
popular choice. They, of course are heat treated through and through.

I grind anvil faces for people on an old G%L model 35 (3hp spindle). I
push it real hard and take 2 to 3 thou per pass at .050" feed and medium
table travel speed. Lots of coolant. You probably know more than I do
about this, but the face of old anvils are almost NEVER parallel with
the base. I have seen them off by as much as 1/4". Attempting to
indicate them in can be frustrating since the face can be sooooo poor.
I have a piece of ground tooling plate that I lay upon the face when I
first sit the anvil on the table. I look for obvious humps and grind
them down with an angle grinder. Once the plate sits more or less in
the same plane as the face, I indicate on the plate and shim the base to
that. That way I have less metal to remove before the face is trued up.
Think about the actual use for the anvil and don't take any more
stock off than you need. A few dings in an area that you won't use
often is preferable to taking so much off that you get down in a softer
area of the face.
And don't be too concerned about the edges. Farriers want sharp
edges all around the anvil, but blacksmiths actually need rounded edges
to prevent cold shuts when shouldering.
So you may want radiuses of 1/8" or so up by the horn end tapering back
to nice and square back by the hardy hole or thereabouts. I try to
leave the edges on the heel sharp for hot cutting.

I never have been able to find out how much weight the table on my
surface grinder can take. Even calling the company 10 years ago or so
didn't get me any help. My machine is an 8" X 20" model and I can get
14 or 15" under the spindle. I try to limit it to about 140 pound
anvils. I don't know what I'd do if I "blew out" the hydraulics!

Pete Stanaitis
------------------------

Stupendous Man wrote:
I am thinking of taking my old anvil to work and using the surface
grinder to flatten it out.
Are old anvils heat treated, or just hardened by use?

Thanks. the thing is pretty hard, gives a nice "bouce", and it's not bad, I
was considering truing it to mallet sheet aluminum out flat, but have a
better plan. I found a 6x24 inch slab of 3 inch steel plate in my garage
that I will surface grind one side of for a benchtop sheet metal anvil. I
don't have a torch big enough to heat treat that monster, so will just
re-grind as necessary.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

"Stupendous Man" wrote in message
...
I am thinking of taking my old anvil to work and using the surface grinder
to flatten it out.
Are old anvils heat treated, or just hardened by use?
--

Old anvils were cast with high carbon iron/steel, then quenched in water.
Fishers were cast with a high carbon face. Then quenched in a stream. Very
hard, but edges chip easily.

Modern anvils are now tool steel and more extensively heat treated.

On Sep 22, 6:10*pm, "Stupendous Man" wrote:
I am thinking of taking my old anvil to work and using the surface grinder
to flatten it out.
Are old anvils heat treated, or just hardened by use?

Resurfacing an anvil, I'm told, is done with welding to build
up a surface of good hard steel, THEN beating or grinding it flat.
The core of the anvil might not be good steel, grinding down
to the core wouldn't be helpful.

Stupendous Man wrote:
... I found a 6x24 inch slab of 3 inch steel plate in my
garage that I will surface grind one side of for a benchtop sheet metal
anvil.

That's cool! Better add handles on the ends - that's a heavy sucker.
I'd like to find a piece like that - you have a better garage than I do
BG.

I don't have a torch big enough to heat treat that monster, so
will just re-grind as necessary.

And if you only use a soft mallet (wood, plastic, leather), you'll never
have to re-grind.

Bob
--
Nota for President

On Sep 22, 9:10*pm, "Stupendous Man" wrote:
I am thinking of taking my old anvil to work and using the surface grinder
to flatten it out.
Are old anvils heat treated, or just hardened by use?
--
Stupendous Man,

I fly-cut the top and bottom of the anvil in the mill first to make it
sit flat on the mag chuck. It weighs only 0-1-8 Lbs so it didn't
overstress the grinder. The top plate is harder than the wrought-iron
body but a file does cut it. It's an English 'Wilkinson', no first
name or logo stamp implying Joshua Wilkinson made it (?). Being so
small it wasn't damaged by heavy use and I only ground the center
smooth, leaving a few small dents and the rounded edges which are
useful for shaping strong rather than decorative tools. The remaining
dents have shinier rings around them which look like the skin of cast
iron after grinding a cross-section of it, so apparently there is some
work hardening.

On Sep 22, 9:55*pm, spaco wrote:

I grind anvil faces for people on an old G%L model 35 (3hp spindle). *I
push it real hard and take 2 to 3 thou per pass at .050" feed and medium
table travel speed. Lots of coolant. *You probably know more than I do
about this, but the face of old anvils are almost NEVER parallel with
the base. I have seen them off by as much as 1/4". * Attempting to
indicate them in can be frustrating since the face can be sooooo poor.
I have a piece of ground tooling plate that I lay upon the face when I
first sit the anvil on the table. *I look for obvious humps and grind
them down with an angle grinder. * Once the plate sits more or less in
the same plane as the face, I indicate on the plate and shim the base to
that. *That way I have less metal to remove before the face is trued up..

Since you want to retain as much of the top (hardened) surface as
possible, why not place the anvil up side down on the mag chuck and
grind the (unimportant) bottom face to match first?

Once the bottom is true to the average of the top, then flip the anvil
and minimum grind the top.

Figuring out how to retain the meat you need is an important skill in
toolmaking. Many times blocks are machined non-ideally (read: the
machinist ****s them up) and then the heat-treat process warps them
even further away from ideal. Rework on a machined/hardened block is a
real pain...

Regards,

Robin

Nice post, Pete. Thanx. FWIW I heard that a good test of a steel anvil was:

Drop a 1" diameter ball bearing from a height of 10". It should rebound back up to 9" if the anvil
surface is properly heat-treated. I'm not sure I believe this. Can someone confirm?

Bob Swinney
"spaco" wrote in message
...
If the anvil is made of steel, not cast iron, then it's face has been
hardened. "old" anvils would be plain carbon steel, somewhere between
about 1070 and 1095. Even though they were usually water quenched, the
section is so thick that the actual face hardness varied a lot. Some
are still almost hard as glass and some are so soft that the face has
actually been deformed toward the edges by the hammer blows and dished
out by use. This dishing is often called the "sweet spot" and some
blacksmiths (not me!)like it for straightening things, since when you
smack the part over the dished area it can overbend enough to exceed its
elastic limit, in a controlled sort of way.
Try filing on an edge to see how hard that one is. The horn and
everything BUT the face should be mild steel or even wrought iron if it
is old enough.
Modern anvils are often made of solid tool steel, 4140 being a
popular choice. They, of course are heat treated through and through.

I grind anvil faces for people on an old G%L model 35 (3hp spindle). I
push it real hard and take 2 to 3 thou per pass at .050" feed and medium
table travel speed. Lots of coolant. You probably know more than I do
about this, but the face of old anvils are almost NEVER parallel with
the base. I have seen them off by as much as 1/4". Attempting to
indicate them in can be frustrating since the face can be sooooo poor.
I have a piece of ground tooling plate that I lay upon the face when I
first sit the anvil on the table. I look for obvious humps and grind
them down with an angle grinder. Once the plate sits more or less in
the same plane as the face, I indicate on the plate and shim the base to
that. That way I have less metal to remove before the face is trued up.
Think about the actual use for the anvil and don't take any more
stock off than you need. A few dings in an area that you won't use
often is preferable to taking so much off that you get down in a softer
area of the face.
And don't be too concerned about the edges. Farriers want sharp
edges all around the anvil, but blacksmiths actually need rounded edges
to prevent cold shuts when shouldering.
So you may want radiuses of 1/8" or so up by the horn end tapering back
to nice and square back by the hardy hole or thereabouts. I try to
leave the edges on the heel sharp for hot cutting.

I never have been able to find out how much weight the table on my
surface grinder can take. Even calling the company 10 years ago or so
didn't get me any help. My machine is an 8" X 20" model and I can get
14 or 15" under the spindle. I try to limit it to about 140 pound
anvils. I don't know what I'd do if I "blew out" the hydraulics!

Pete Stanaitis
------------------------

Stupendous Man wrote:
I am thinking of taking my old anvil to work and using the surface
grinder to flatten it out.
Are old anvils heat treated, or just hardened by use?

Nice post, Pete. Thanx. FWIW I heard that a good test of a steel anvil
was:

Drop a 1" diameter ball bearing from a height of 10". It should rebound
back up to 9" if the anvil
surface is properly heat-treated. I'm not sure I believe this. Can
someone confirm?

I have never heard that one before. My anvil says "chrome alloy" on it, but
no name. I just happen to have a box of ball bearings up to 3 inches on the
shelf behind it. A one inch ball bounces back 7.5 inches on mine.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

Stu sez: "I have never heard that one before. My anvil says "chrome alloy" on it, but
no name. I just happen to have a box of ball bearings up to 3 inches on the
shelf behind it. A one inch ball bounces back 7.5 inches on mine."

That seems to lend a bit of credibiity to what I think I heard. Upon further reflection, I wonder
if my source wasn't referring to a specif heat treat on a specific anvil.

Bob Swinney

"Stupendous Man" wrote in message ...
Nice post, Pete. Thanx. FWIW I heard that a good test of a steel anvil
was:

Drop a 1" diameter ball bearing from a height of 10". It should rebound
back up to 9" if the anvil
surface is properly heat-treated. I'm not sure I believe this. Can
someone confirm?

--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

On Wed, 24 Sep 2008 16:50:27 -0500, "Robert Swinney"
wrote:

snip
Drop a 1" diameter ball bearing from a height of 10". It should rebound back up to 9" if the anvil
surface is properly heat-treated. I'm not sure I believe this. Can someone confirm?

I've heard of building your own hardness tester using this
method.

You need some known items of hardness for calibration
though. Find some glass tubing maybe 10-20 inches long that
you can make marks on and your steel ball will easily slip
into. Using a known surface drop the ball (from the same
height) and note (mark) how high it bounces up. Repeat
several times and take the average. Repeat process on
another known item. Test your unknown item and note how high
the ball bounces.

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On Thu, 25 Sep 2008 13:00:56 -0400, Leon Fisk
wrote:

On Wed, 24 Sep 2008 16:50:27 -0500, "Robert Swinney"
wrote:

snip
Drop a 1" diameter ball bearing from a height of 10". It should rebound back up to 9" if the anvil
surface is properly heat-treated. I'm not sure I believe this. Can someone confirm?

I've heard of building your own hardness tester using this
method.

You need some known items of hardness for calibration
though. Find some glass tubing maybe 10-20 inches long that
you can make marks on and your steel ball will easily slip
into. Using a known surface drop the ball (from the same
height) and note (mark) how high it bounces up. Repeat
several times and take the average. Repeat process on
another known item. Test your unknown item and note how high
the ball bounces.
See: http://en.wikipedia.org/wiki/Schmidt_hammer
Just before I retired, the technical data centre manager showed me one
and asked if it was worth keeping or if I wanted it, wish now I had
taken it instead of explaining (and showing him on one of the exposed
building columns) how it was used to estimate the strength of
materials.
Gerry :-)}
London, Canada

On Sep 25, 1:00*pm, Leon Fisk wrote:
On Wed, 24 Sep 2008 16:50:27 -0500, "Robert Swinney"

Drop a 1" diameter ball bearing from a height of 10". *It should rebound back up to 9" if the anvil
surface is properly heat-treated. *I'm not sure I believe this. *Can someone confirm?

I've heard of building your own hardness tester using this
method.

You need some known items of hardness for calibration
though. Find some glass tubing maybe 10-20 inches long that
you can make marks on and your steel ball will easily slip
into. Using a known surface drop the ball (from the same
height) and note (mark) how high it bounces up. Repeat
several times and take the average. Repeat process on
another known item. Test your unknown item and note how high
the ball bounces.

--
Leon Fisk

My scleroscope rebounds to 4 of 10 off my anvil, which definitely has
a plate welded on the top. A carpenter's hammer reads the same, a HSS
bit held in the milling vise reads 6. The anvil can be filed with some
difficulty. It's fine for hobby work.

It's quite difficult to get the same reading repeatedly off small
samples even when they are clamped in a vise, and this is a
professional instrument, although an old one in suspicious condition.

I would hold the glass tube upright with a level to minimize friction
and record the rebound against a ruler with a digital camera video.

Jim Wilkins