Power hammer anvil info

[Mainely,Bob]

There was a post about a 150 pound hammer for sale that bounced off the rails over in the IFI store section but it did offer up some very valuable information and myths about power hammers in general and hammer anvils in particular.
I have no idea if this info can be harvested and posted where it`s easy to find but I think it would be very much worth the effort for someone like me who is building a hammer to be able to refer to it in the future.

That being said and now that you know where to find said info,someone there asked if adding a thick base plate under an existing hammer was a viable way to increase the anvil to tup ratio which seems to be a widely accepted minimum of 10:1 for acceptable performance under general conditions.
Some folks say the anvil consists of only the single piece of steel that supports the dies.Others said that anything contained within a triangular area flaring out at 45 degrees from the bottom die(tentatively called the "cone of influence")counts toward the weight calculated in that ratio.

What then are your thoughts on proper anvil construction and the ratio of tup to anvil?Please be willing to back your statement with fact,personal experiences that can be either verified or duplicated or the ever popular video.

Gentlemen,the floor is open and I both await and thank you in advance for your responses.

[arftist]

I am not familiar with the terminology. For the uninformed, like me, please define "tup". Thank you very much.

Here is my understanding, as explained to me by Frosty;

Tup is the striking part or hammer

Sow block is the anvil

[Timothy Miller]

I have been told that the tup is the ram, upper die and die key. Basically all of the parts moving up and down doing the striking. The anvil or anvil block is the part of the hammer that the sow block and lower die is attached to that receives the energy of the downward blow. not all hammers have a sow block.

[Mark Wargo New2bs]

I talked with Clay Spencer over at a Mississippi Forge Council event in July and he said that a 4:1 anvil to hammer ratio was fine.

Mark

[Timothy Miller]

question: would the leaf springs from which my head is suspended from be considered part of the tup-weight?

I don't think so because they don't have a rigid connection to the ram. The link arms that connect the ram to the spring would though. Another way to look at is what is the falling weight of all of the parts.

[arftist]

I will contribute my understaning of the physics behind the problem and let the engineers and hammerologists correct me.

The ideal anvil would be firmly bonded directly to the bedrock of the largest (heaviest tectonic plate on the earth, in addition to having almost ifinite mass (weight). Blows struck on this anvil would penetrate or flatten the work more than the exact same blow on any other anvil in the world. Since this is usualy not the case, the closest one can come to this scenario the better, limited only by money, space or location. Minus this connection to the earth, the anvil may as well, if you consider the most extreme veiw possible, be floating freely in space, including the weight of its base, footing or slab, and in a sense the weight of the entire machine, if it be a power hammer anvil. The majority of the work which occurs during a hammer blow against an anvil is a result of the inertia of the anvils total mass, its own ability to resist moving away from the hammer blow's impact.

Bob, you asked for experiencial evidence. In my attempts to find the ideal dampening medium for my power hammer (on the cheap of course) I tried gasket material from the hinged body joint of a dumpster truck. About 1" thick rubber but pretty soft. Ended up making a great seal for the garage door bottom, still there. I tried to whack some metal, but something was wrong. Everything was working fine, heck the machine was almost brand new still. In spite of a 75 pound hammer at ful throttle, aroun 210 blows per minute, with over 11" of stoke, I coundn't even splinter a wooden broom handle. It would dent a bit, but even minutes of hammering wouldn't split it. Cured it by replacing the foam rubber with 1/2" thick conveyor belt. When I get it bolted to a 3 or 4 ton heavily reinforced block it will hit harder. Using the 45 degree "cone of influence" theory, the entire concrete block will add to inertia. It will not make up for much of the lacking caused by too small an anvil though, because some of the advantage on a large steel anvil is due to the elasticity of steel, it's ability to return to it's original shape after deformation, thereby walloping the work, again, from underneath, when it reacts to the impact of the hammer blow.

[Timothy Miller]

second question: my bigger triphammer, a williams and white, is a one-piece casting, with the "anvil" not differentiated from the rest of the casting for the hammer, how do you calculate the anvil weight for such a hammer, or must I guesstimate?

I think it would have be a guesstimate. Unless you were to dip it in tank of water and see how much it displaces than calculate that the weight in that volume of cast iron. But that looks like a very robust hammer I doubt it was under built .

[Timothy Miller]

I will contribute my understaning of the physics behind the problem and let the engineers and hammerologists correct me.

The ideal anvil would be firmly bonded directly to the bedrock of the largest (heaviest tectonic plate on the earth, in addition to having almost ifinite mass (weight). Blows struck on this anvil would penetrate or flatten the work more than the exact same blow on any other anvil in the world. Since this is usualy not the case, the closest one can come to this scenario the better, limited only by money, space or location. Minus this connection to the earth, the anvil may as well, if you consider the most extreme veiw possible, be floating freely in space, including the weight of its base, footing or slab, and in a sense the weight of the entire machine, if it be a power hammer anvil. The majority of the work which occurs during a hammer blow against an anvil is a result of the inertia of the anvils total mass, its own ability to resist moving away from the hammer blow's impact.

Bob, you asked for experiencial evidence. In my attempts to find the ideal dampening medium for my power hammer (on the cheap of course) I tried gasket material from the hinged body joint of a dumpster truck. About 1" thick rubber but pretty soft. Ended up making a great seal for the garage door bottom, still there. I tried to whack some metal, but something was wrong. Everything was working fine, heck the machine was almost brand new still. In spite of a 75 pound hammer at ful throttle, aroun 210 blows per minute, with over 11" of stoke, I coundn't even splinter a wooden broom handle. It would dent a bit, but even minutes of hammering wouldn't split it. Cured it by replacing the foam rubber with 1/2" thick conveyor belt. When I get it bolted to a 3 or 4 ton heavily reinforced block it will hit harder. Using the 45 degree "cone of influence" theory, the entire concrete block will add to inertia. It will not make up for much of the lacking caused by too small an anvil though, because some of the advantage on a large steel anvil is due to the elasticity of steel, it's ability to return to it's original shape after deformation, thereby walloping the work, again, from underneath, when it reacts to the impact of the hammer blow.

I have often wondered if you had two rams one striking up and one striking down both hitting the stock equally what would that work like? No anvil needed.

[Grant]

Good morning All

Is there an efficiency argument to be made for a larger mass anvil. If one is not driving the anvil through the planet does a 150 lb anvil offer more resistance to the iron than a 75 lb one? -grant

[JNewman]

I have often wondered if you had two rams one striking up and one striking down both hitting the stock equally what would that work like? No anvil needed.

We recently discussed this across the street. It's called a counterblow hammer. Counterblow hammer <link

[Nakedanvil - Grant Sarver]

Good morning All

Is there an efficiency argument to be made for a larger mass anvil. If one is not driving the anvil through the planet does a 150 lb anvil offer more resistance to the iron than a 75 lb one? -grant

Just try hand-hammering on a 20 pound anvil compared to a 200 pound anvil! Even a block of concrete under it doesn't help much. As arftist pointed out, it's not just weight, it's the weight combined with the elastic properties of iron/steel.

[Dave Hammer]

For Grant from Colorado... The short answer is YES... The greater to mass of the anvil (up to at least 20-1) when compared to the mass of the ram (or hammer), the greater the efficiency of moving metal.

[arftist]

Just try hand-hammering on a 20 pound anvil compared to a 200 pound anvil! Even a block of concrete under it doesn't help much. As arftist pointed out, it's not just weight, it's the weight combined with the elastic properties of iron/steel.

Grant, allow me to show my ignorance. How does the elasticity of steel compare to that of cast iron, which is what I asume you mean by iron. I would guess that steel is much more elastic.

[Nakedanvil - Grant Sarver]

Grant, allow me to show my ignorance. How does the elasticity of steel compare to that of cast iron, which is what I asume you mean by iron. I would guess that steel is much more elastic.

Elasticity is inherent in iron. The elastic limit is different in differing alloys. Cast iron is elastic but has a lower elastic limit than steel, as does pure iron. Comes down to pounds per square inch. You can make a good anvil from cast or wrought iron IF you securely attach a steel plate to the top that resists deforming and spreads the load out, transferring the concentrated hammer blow out onto a larger area. Some (small) deformation can still take place as witnessed by anvils that become swayed over time.Don't believe I've ever seen that on a cast steel anvil.

[arftist]

Elasticity is inherent in iron. The elastic limit is different in differing alloys. Cast iron is elastic but has a lower elastic limit than steel, as does pure iron. Comes down to pounds per square inch. You can make a good anvil from cast or wrought iron IF you securely attach a steel plate to the top that resists deforming and spreads the load out, transferring the concentrated hammer blow out onto a larger area. Some (small) deformation can still take place as witnessed by anvils that become swayed over time.Don't believe I've ever seen that on a cast steel anvil.

Could that have anything to do with cast steel anvils being so much newer than wrought iron/steel anvils, therefore not having had enough time to become swayed?

[Grant]

Just try hand-hammering on a 20 pound anvil compared to a 200 pound anvil! Even a block of concrete under it doesn't help much. As arftist pointed out, it's not just weight, it's the weight combined with the elastic properties of iron/steel.

Thanks Grant. I'm not trying to promote my sophomoric ideas I am trying to understand the forces involved and I'm a firm believer in anecdotal evidence. But, it is hard for me to imagine that the steel/iron in an anvil is deflecting with the blow. I am not saying it is not true; it is just hard for me to image it. -grant

[Nakedanvil - Grant Sarver]

Could that have anything to do with cast steel anvils being so much newer than wrought iron/steel anvils, therefore not having had enough time to become swayed?

Ask me that question 50 years from now! But probably not, the physics suggests it probably won't happen, or might take considerably longer. Course some anvils get used with one or more strikers, be a whole lot different than one that was only used with a four-pound

When the elastic limit is exceeded the material deforms. A solid cast steel anvil will have a higher elastic limit all the way through.

[Nakedanvil - Grant Sarver]

Thanks Grant. I'm not trying to promote my sophomoric ideas I am trying to understand the forces involved and I'm a firm believer in anecdotal evidence. But, it is hard for me to imagine that the steel/iron in an anvil is deflecting with the blow. I am not saying it is not true; it is just hard for me to image it. -grant

Don't worry, your questions are on target. Yes, hard to imagine.

So let's start with things that are easier to imagine. You drop a rubber ball on concrete and it bounces back up. Why? It's elastic of course. When it hits the concrete, the bottom of the ball stops and the weight of the rest of the ball causes it to compress. Being elastic it returns to it's original shape. It can't expand downward so it's energy re-expands it upward so it now has upward inertia, hence it bounces. Try that with an inelastic material like soft clay and it just goes splat. So if a rubber ball can do that and even a bowling ball can do that, is steel any different?

A steel ball will bounce the same way IF is strikes a surface that is as hard or harder. Any deformation (such as a hard ball striking a piece of mild steel) will take energy away from the bounce. Also if the surface it hits can move away it will rob energy.

So, if a hammer acts the same way it probably is doing the same thing (and is in fact). It's easier to imagine if we put a coil spring on a handle so it looks like a hammer. Strike something with with it and that spring compresses then re-expands pushing it off of the surface and makes it bounce. Springs work only because steel is elastic. A solid steel hammer is doing the exact same thing. When it hits an unyielding surface, it compresses and springs back to shape. You can't see this happen, because compressing something the size on a hammer even a few thousandths of an inch requires a great deal of energy and happens very fast, but it happens nonetheless.

[todoned]

I have a Kinyon style hammer I built and it is what it is. One thing that continues to surprise me, is there seem to be a large number of variables that result in a well performing or poor performing hammer. It seems as if there are some foundations that cause a lot of problems (I would have thought arftist's 1" rubber would be fine), or mysterious tuning that has to be done, etc. Everybody raves about the Iron Kiss and I may buy one some day, it looks great...but the one time I had a chance to see one in person (2008 Ashokan in NY) it was bouncing around like crazy on a concrete foundation and my perception (could be wrong) was that John left early because his hammer was not performing well (quite poor actually). I have seen Little Giants that awe me with how much metal they can move, others that are quite anemic. Maybe the mystery is why we are all so fascinated with the subject! I've attached a photo of my hammer -- one thing I haven't heard discussed much before, is the approach I used -- purchasing a linear slide used off of Ebay. There was a time when I didn't want any competition from others looking for such slides (they don't come up that often) but at this point I don't think I'll be building another one anytime soon. Have others tried this? Maybe it won't hold up, I don't know -- I hope it does! So far so good, after about 5 years of somewhat infrequent usage.

-Tod

[monstermetal]

I have not done it... But I bought a couple of big linear bearings to try it.... I started reading what the bearings would take and thought maybe it was not the best thing... they will take straight loads very well... but a little side load and they dont do so well

[forgemaster]

I have often wondered if you had two rams one striking up and one striking down both hitting the stock equally what would that work like? No anvil needed.

Already been invented, called a counterblow hammer, they are normally always a closed die hammer.

Phil

[Timothy Miller]

wonder if you configured the two rams horizontally and added some sort stock rest what that would be like. Obviously the rams would need to be synchronized could you make a much more powerful machine that weighed a lot less. Just really thinking out loud.

[Grant]

A solid steel hammer is doing the exact same thing. When it hits an unyielding surface, it compresses and springs back to shape. You can't see this happen, because compressing something the size on a hammer even a few thousandths of an inch requires a great deal of energy and happens very fast, but it happens nonetheless.

Thanks Grant -It would seem that some "unyielding surface" is less unyielding than others. -grant

[Mainely,Bob]

wonder if you configured the two rams horizontally and added some sort stock rest what that would be like. Obviously the rams would need to be synchronized could you make a much more powerful machine that weighed a lot less. Just really thinking out loud.

You might want to look a some of the videos of the shops that made things like shovels and other garden tools.
They flattened stock by placing it between 2 constantly moving syncronized rollers.These rollers had large flats machined in them that allowed the operator to stick the hot steel between them once every revolution.Unlike rolling mills, the rollers were turning toward the operator and the work was pushed back toward him so there was little danger of being drawn into the machine.
I was impressed by how quickly the stock was transformed by this process.

[pkrankow]

Ask me that question 50 years from now!

I hope we all can do just that!

Phil