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Anvil stand mass and stiffness

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In thinking about anvil stands, it seems like the mass of the anvil stand would only add to the effective mass of the anvil if it is solidly supporting/attached to/backing up the anvil.

For instance, If you set a 66# cheap steel anvil on top of a 300# anvil, it might work like a striking plate on a 300# (or 366#) anvil, but if you put the same 66# anvil on top of a 300# box of sand, or a 300# spring contraption, it might work just like a 66# anvil.  Added weight in the stand that isn't as nearly stiff as the anvil might help with stability and ringing, etc, but wouldn't necessarily add to the anvil mass at the instant of impact.

Or another way to think of it--if the connection between the anvil and stand isn't good, isn't it somewhat like the delaminated face of a dead anvil?

Wouldn't a big hunk of cast iron, like an old engine block, make a solid stand that added to the effective mass of the anvil?

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There are solid steel stands for anvils around, and yes, they do add to the overall mass of the anvil. This is why a stump anvil can function at all. This is also why small anvils well fixed to a solid base can work. Joey has a lot of video's on the tube about this ; for example: 


But other than sheer mass; there's also something like resonance; I don't claim to understand the fysics behind this; but the more rigid your anvil is connected to it's base, the better it will work. I tested this once with industrial glue; and that experiment is still holding up without problems: 


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Yeah, I was thinking about the way that "mass", "resonance", and "working" are different issues.  Epoxy deadened your ring, but you have the same mass.  Did epoxying make any other difference than the ring?

Resonance-wise, I have a shiny #66 Acciao anvil and it rings brightly. Geeking out like an engineer, I worked out the natural frequency of a similarly-sized steel beam (https://www.engineeringtoolbox.com/structures-vibration-frequency-d_1989.html ) and it doesn't seem too far off from the tone. I can quench the ringing with a magnet, gripping a horn in a fist, clamp, a plumbing T, or jamming a chunk of 2x4 over it.  I also clamped the base to a flimsy bit of 3/8" plywood with some wood clamps, and that also quiets the ring somewhat.  Setting it in a bed of sandy dirt on the ground didn't seem to do too much to the ring.  

Joey's tiny anvil was moving around under the clamps with each hit--A small anvil might "work" for a short job, but people really seem to think the big ones are worth it.  Would a 66# anvil epoxied to a 66# box of sand work like a 132# anvil on a stool?

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On 3/5/2021 at 8:57 PM, Dave F said:

Yeah, I was thinking about the way that "mass", "resonance", and "working" are different issues.  Epoxy deadened your ring, but you have the same mass.  Did epoxying make any other difference than the ring?

Joey's tiny anvil was moving around under the clamps with each hit--A small anvil might "work" for a short job, but people really seem to think the big ones are worth it.  Would a 66# anvil epoxied to a 66# box of sand work like a 132# anvil on a stool? 

Well, actually, yes. The one where I glued the wood stump also to the concrete with the same glue; it feels "heavier" under the hammer. You feel the hit in your feet through the concrete. The other one doesn't vibrate in your shoes :D 

I think - and take this with a grain of salt - that the harder you fix your anvil down, in combination with the reduction in resonance-difference between anvil and foot; the more energy will be reflected into the deformation of your work.  This is also why a steel tripod with a really strong fixation works so well. I found an article about it once; someone tried to find out how to mathematically find out how heavy an anvil had to be to be "optimal" for a power hammer, in this article they described resonance, vibration; and plastic deformation of the workpiece. They experimentally measured this; and found that from a 1/20 ratio between hammer/anvil; the increases in mass of the anvil didn't really increase deformation proportionally. Below 1/20; it was usefull to get a bigger anvil. They also found that the fixing method of the anvil to the frame mattered in noise, but not in deformation. If I'd find it again, I'd link it. :D Hence forth power hammer anvils' mass are between 1/5 to 1/20 .

Do the experiment of the stump anvil; and you'll be amazed. Take a sledgehammer head; weld a square spike on it; go outside; and beat it in a stump of wood preferably still with roots. You'll be amazed how "heavy" the tiny anvils feels. It's virtually impossible a part of the "experienced mass" doesn't come from the base. 

But; I have learned to NOT overthink a lot of things, as I tend to do that (a couple good whisky's usually fix that problem :D. Sometimes it's more important to just "do"; and don't worry. A small anvil is no excuses for not delivering good work; and having a massive workshop with all the tools, presses and tons of anvils is no excuse either to not deliver good work. It starts with your mind, you motivation, and flows from there. And once you start working on something, improvise. Half the fun (for me at least) of blacksmithing / bladesmithing is experimenting with stuff. Sometimes it's a bad idea, sometimes it's a good idea. Just like anvils. Try a different foot, try a different fixing method ... in the end you'll find what works best for you; and that's what matters. 

Yup, I had a bad day, and a good Talisker port rouge in front of me now :D

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The mass of the stand is far less important than how the anvil is connected to the stand and how the stand is connected to the earth.

All things considered, if those two connections are "perfect", you now have the mass of the earth under your hammer blow plus that of the stand and the anvil. 

I use a wooden stump cut to fit my anvil and buried 2'-3' into the ground. I inset my anvil into my stump and the inset is deep enough to lay in fine sand to level my anvil. The fit of anvil to stump is tight. I have very little loss to vibration or movement. 

Oh, and the sand deadens the ring of the anvil.

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Only if Earth were solid under you. 

Solidly connected is good, the weight of the stand beyond what's needed to not flex or bounce around is pretty insignificant. 

I've yet to see ANYBODY provide evidence a heavy stand makes a difference, not opinion, actual test data. 

Frosty The Lucky.

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My stand plus the anvil weight is close to 1700# and has performed great. The immobility of the unit helps with bending, upsetting and heavy striking. I can “cold bend” 5/8” sucker rod in the pritchel hole. 
That being said, the stand took three solid days to build and it was well worth it IMO. 
If you are getting a stand together I would aim for “immobility” under and usage and then move on from there  


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Pushing forward to good-enough, here's my 66 lb Acciaio anvil on a 130# Cherry stump.  Sitting free, it hurts my ears.  Wedged down, it quiets a bit.  Adding magnets, the ring is mostly a click:



At 20:1 anvil:hammer weights, (with lots of simplifying assumptions, like a perfectly inelastic collision where the work's deformation absorbs all of the rebound, and the anvil floats free in space and doesn't pass any energy on to anything else) the energy after the collision is only 4.5% for noise, wobbling and everything else. With my 2.5# hammer vs a 66#, it's 3.7% leftover, 40:1 would be 2.4%, 80:1 would be 1.2%, 100:1 would be 1%.

If my stump-wedge setup acts like 130# of steel perfectly welded to the bottom of my anvil, the best I'd possibly get is 99.42%

I'm sure I'm not skilled or conditioned enough to notice a 3% difference lost, so I think it's good enough for now. 

I think I like my wedge setup -- I can tighten it with a tap, and break it down with just my hammer and put the anvil into the shed in less than a minute. The only trick is to cut the wedge first, and use it to mount the 2nd dovetail.



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Overthinking things, here's a table of hammer:anvil ratios, and, assuming your anvil is mounted on soft springs, and a clay-like workpiece deforms and absorbs all the energy it can to decelerate the hammer and accelerate the anvil into a perfectly inelastic collision:

Anvil   eff     eff
ratio   work    non-work
   1:1  50.00%  50.00%
   2:1  66.67%  33.33%
   5:1  83.33%  16.67%
  10:1  90.91%   9.09%
  15:1  93.75%   6.25%
  20:1  95.24%   4.76%
  30:1  96.77%   3.23%
  40:1  97.56%   2.44%
  50:1  98.04%   1.96%
  60:1  98.36%   1.64%
  70:1  98.59%   1.41%
  80:1  98.77%   1.23%
  90:1  98.90%   1.10%
 100:1  99.01%   0.99%
 120:1  99.17%   0.83%
 140:1  99.29%   0.71%
 160:1  99.38%   0.62%
 180:1  99.45%   0.55%
 200:1  99.50%   0.50%
 500:1  99.80%   0.20%
1000:1  99.90%   0.10%

The lost non-work% (the motion of the anvil into the springs) is the energy that is available to be recovered by a better, stiffer stand. Elasticities in the hammer, anvil, or workpiece would come out of the effective work % assumed to deform the workpiece, and that loss would end up as kinetic energy in rebound, or noise.  It's interesting to think that the colder and more elastic the work is, less deformation and more rebound will happen--at 40:1, you could easily lose more energy to bouncing off cold material than to a sloppy stand.

Frosty, yes, it seems like rapidly diminishing returns above 20:1 or 40:1.    

The mass of a stand can add to the effective mass of an anvil, but only if it is stiff enough to return the energy back into the workpiece while it is still being deformed.  500# of soft springs might eventually return the anvil to position, but they won't be fast enough to do useful work during the ~0.0005s the hammer is deforming the steel. Steel bolted to the anvil would add mass, but maybe a sand filled leg or box would add mostly sound damping and stability.

Noise-wise, clamping the anvil well can change the natural frequency, and the coupled stand can also dampen the vibrations.  There's probably complicated frequency-dependent impedance matching issues at the interfaces between anvil, stand, and floor if they are different materials.

BsnNFrnt Stability-wise, I was first worried about moving around or safety from falling over.  I can see that real immobility can be good for more than that. 


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What did I say about not overthinking things ? It hurts the noggin' after a while, and you get less work done. :D 

Nice cherry stand though; I'd make sure it's as dry as desertsand; remove the bark; and then add some straps around it to prevent it from cracking. And if you keep it dry; you'll have a functional forging setup which your grandchildren can still use.

I also like the wedging idea ... It's like how they clamped down sharpening stones; just bigger.

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Aw, overthinking it this way puts bounds on how much time to waste doing things.  How about a picture or two:



The bigger the anvil:hammer ratio, the less energy goes into moving the anvil and more goes into moving the work.  Up past 40:1, a bigger anvil (or stand that adds to the responsive mass of the anvil) works on the last 2.4%.

Now I should quit and start working on the bands, or better, a forge or, a roof over the stump.


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Lol, you need to check your premice. It fails because you never set your anvil on any kind of spring. Your goal is zero movement between anvil and stand and zero movement between stand and ground. If these are maxed, the mass under your hammer equals the mass of the earth. 

This may be a hobby for many, but it's not a hobby horse mounted on springs.  

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Check my premise? It's springs all the way down--solids, from diamond, through steel, concrete, wood, rammed earth, bedrock, wood, silicone caulk, all have elastic coefficients. The energy that propagates far (2 meters?) into the earth due to movement won't be return in time to deform the workpiece.

My assuming a negligible hobby-horse spring suspension as the worst possible stand gives an upper bound on how much better a better stand could be.   The other bound is the zero kinetic energy in a perfectly solid, mass-of-the-earth, zero-movement, anvil+stand.  The space between those two bounds is the kinetic energy lost due to the anvil moving due to any motion or springiness in the anvil+mount.

Impact-wise, if you set a 300# anvil on a platform with 300 1# springs and hit a workpiece with a 1# hammer, it can't perform more than 0.33% worse than if you cast the base directly into 1,000 tons of cast iron. If your mount is better than some negligible springs, you get extra credit for the extra mass effectively coupled to your anvil.  The cast base will perform better, but there really isn't much energy that can make it through a heavy anvil into a stand. For a light anvil, a good base could make a huge improvement.

You could neglect that materials act like springs and dampers, but as you get down into paying money, time and effort for improvements, the material properties may begin to matter.  At the light end of things, couplings and support materials might matter much more than at the heavy ratios, like how one might hold up a rivet dolly against a 1# hammer, versus a monster anvil sitting on a shop floor.


-- looks like a stake anvil in a log steadied by a foot. A good log probably matters there.

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It may also be a situation similar to how my late father-in-law (a medieval history professor) described an artist's depiction of an elephant, "He may have seen an elephant once but it was a long time ago and from a distance."  Here the carver may have been depicting what he recalled from a visit to a blacksmith shop but his memory was a bit faulty. Or, the hammer face may have detached from the rest of the carving over the centuries.

"By hammer and hand all arts do stand."

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I'd go for broke off too; with the amount of carving on that building I'd wonder how many carvers were involved and who did the design work.

I have two single lung bellows paired for use for Y1K demos; they do take a separate person for effective work. (I call them the "bellows thrall".)  One of the neat things is that with proper pumping you don't need a check valve on the nozzle as the out flow from one overpowers the inflow from the other, especially as there is a larger inlet valve on the base board.  This is especially the case where there is a gap between the nozzle and the tue pipe. 

This is seen in archaeological finds and Rehder, ("Mastery and Uses of Fire in Antiquity"), theorized that it was to entrain more air; but did the math to show it didn't work.  I corresponded with him pointing out how it kept the nozzle from pulling small bits of burning charcoal into the body of the bellows where it is a right pain to extinguish! (Jamming the nozzle into a quench tub and snorting water up into it and shaking it about works, but is time consuming if your bellows is fastened down for easier use.) Experimental Archaeology for the win!

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Again, check yet premice and read yer books. When you strike an object, what happens at the other end of the object(the stand)  is instantaneous with your initial blow, and their is no "return". 

You have loss of force at every change of material. This includes the air your hammer travels thru, the material and hardness of your hammer, the material and hardness of your anvil, the quality of your connection between anvil and stand and finally the quality of the connection of your stand with the earth. The better your connections, the less loss of force. Thus the more initial force which can be applied to your hot iron. 

The "elasticity" or distortion between a properly heat treated hammer and anvil is neglible. The elasticity of iron at a yellow heat between said hammer and anvil is appreciable. 

Hammer rebound isn't caused by force returning from some distant point, it is the difference between force transmitted at the point of contact and the initial force applied. What remains is what balences the equal and opposite reaction equation and is measured as hammer rebound. A 90% rebound means a 10% "loss of force. This 10% is not " lost". It has been converted into another kind of energy, usually heat.

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Which premise is wrong?  I'm trying to say that the energy you lose to a real-sized anvil & stand has to be bound between the real-sized anvil free-floating in space and a perfect, earth-sized anvil, and that any losses at the changes of material between the anvil and the stand, the stand and the earth, or to the cruddy materials the stand is made out of, or the soft, peaty earth under my log, all must fit within those bounds.

Those losses at every change of material are the elasticity and ductility of the material, and the impedance mismatches between the differences in densities and propagation speeds at the interfaces.  The quality of those connections are measured in well they reflect, transmit, or transform energy.  

The instantaneousness of the impact depends on the ductility (and elasticity) of the work.  You can measure the force-time impulse with expensive sensors, but the quick & dirty way is to divide the depth of the deformation by speed of the hammer per-impact--If you let a hammer drop 1 meter onto your yellow heat steel, it will be going 8.85m/s, if it makes a 1mm deep divot, the impact took ~0.001m/(8.85m/s)=0.113ms.  The shallower the divot, the faster the impact (at zero depth, it's how long it takes to compress your elastic hammer or anvil like a spring).

I used a premise of 0% rebound, as if I hit a chunk of sticky, soft lead, doing the maximum possible about of work to the workpiece, to focus on the energy that is transferred into the anvil system.

Using those premises, doing the physics 101 inelastic collision math reproduced the result that a 40:1 anvil:hammer ratio is pretty good, and puts numbers to just how good it is (97.6%) relative to heavier or lighter ratios.  The first is well known, but the I thought the second was pretty interesting: This measure of anvil efficiency is basically 1-hammer_mass/(hammer_mass+anvil_mass)   You can get some extra anvil_mass credit for better support, and a 150# dead, delaminated anvil might work like a 10# anvil poorly coupled to a 140# base.

I'm not claiming that the sound energy propagating down through the steel, stand, earth, and bedrock will rebound back up to deform the workpiece, I'm claiming that depending on the size of the anvil, there's limits on how big the losses between the anvil & stand and between the stand & earth, and how much stand improvements or any possible voodoo can make an anvil "work" like a bigger anvil.

If you think my tables and graphs should bend differently because I've got the premises wrong, please tell me.


There's other important criteria for stands, like portability, noise, stability, immobility, maintainability, functionality, and carvings.

Noise-wise, I might experiment with caulk, but I think this double-horn Acciaio might be shaped like a tuning fork, and improved holding of the handle of the tuning fork might not solve it.

Here's a time-spectrogram of my movie above, (using "Audacity") showing the frequencies of the paired taps on the loose, wedged, and magnet-ized anvil.




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Well; if you really wanna overthink this; the power and mass of the magnets also matter; the tiny ones you are using produce the "click", if you would be using really strong heavy magnets, that would even go away :-)

I use those on-of welding type square magnets; about 2 pounds each under one horn, and my cleaning brush under the other horn; that usually deafens an anvil completely.


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Out of curiosity, where on the anvil did you put the point of impact when you took that spectrogram? Not trying to send you down a rabbit hole, I'm just personally curious in your data since you went through the trouble of collecting it :P

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BartW: Yeah, mass on the horns do a lot for noise.  I was surprised how much just gripping a horn in a fist quieted the ring.

Twigg: I tapped near the center of the face.  It was a spectrogram of the audio track from the iPhone video posted on Youtube.  The entire documentation of my data collection procedure is contained within the video. 

Since it's somewhat awkward to extract the data from Youtube, I attached an MP3 file of the audio data.  I opened the video file with Audacity audio editor (free from https://www.audacityteam.org/ ) and clicked the Track's downward-triangle to choose "Spectrogram".  One could also use Audacity's Analyse/Plot Spectrum tool, but the spectrogram gave a pretty decent overview.

I just noticed that the "MultiView" option is cooler:





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