Hammer size vs Anvil Size

[Mr Smith]

One thing I came across is the effect of pressure - defined as force / area.

A chisel will place more pressure on the face of the anvil than *any* hammer will ever be able to, therefore, more deformation or damage.

Also, when you double the size of any one face of a square-faced hammer, if the hammer is kept in proportion, the weight increases by a factor of eight.
eg 1x1x1 = 1, but 2x2x2 = 8. There is also a non-linear increase in weight with cylindrical hammers, but it is not as pronounced.

What does this mean for the anvil? Well, most times the hammer strikes the anvil, it will be at an angle - giving the familiar "hammer mark". Because the length of the hammer mark caused does not have a linear relationship with the mass of the hammer, it follows that a larger hammer exerts a greater pressure on the face of the anvil when you miss the workpiece.

Therefore chisel = very bad - sledge = bad - hammer = less bad

Not sure if there's any reason why a small anvil should be any more / less resistant, other than the post made by Rantalin, but like I say, all of the info keeps coming back to "be careful and take care of your anvil"

[Rich Waugh]

A couple of things that were brought out in the anvil/hammer discussion on Anvilfire weren't mentioned here, and are definitely cogent.

In making a wrought iron/tool steel anvil, the rate of heat abstraction is definitely affected by the mass of the anvil. That is obvious. As mentioned, anvil makers used a water stream flowing over the anvil face to quench it. I have seen no mention anywhere that any anvil manufacturer had several differing volumes/flows of water for different sizes of anvils, and it stands to reason that they didn't. Just not that easy to do when you're dealing with diverting flow from a millrace into or near a forge area. They probably just worked with what was reasonable to do, and it was a bit much for a very small anvil and a bit too little for the really big ones.

The cube/square law appolies in anvils, meaning that there's a vast difference in mass for not a lot of difference in surface area. That mass is what necessitates more and faster ehat abstraction if you're goin gto get effective quenching.

Most importantly though, a factor that *was* in the discussion on Anvilfire that hasn't been raised here, is that you expect a big anvil to used with strikers using big sledges. Big sledges mean big forces when a blow is missed. That means that if your big anvil has a really hard face, one missed blow with a sledge will knock a really big chunk out of the anvil's edge. That gives anvil makers a bad reputation if it happens more than once, I would think. Seems reasonable to me that bigger anvils, destined to be used by strikers, would have be made with a more forgiving face hardness.

ON the matter of anvil v hammer mass, you can't can't ignore physics. If you want to resist the hammer's *force*, you need sufficient mass, since the anvil has no velocity.

[HWooldridge]

Rich,

The sledging on large anvils is a very good point as a full overhead swing that misses could be catastrophic. Another issue with regard to quenching is that faceplates did not seem to differ drastically in thicknesses. I have seen many smaller anvils in the 3/8" range but few big anvils with 3/4" or 1" plates. I haven't seen every anvil so maybe they exist but perhaps the shear steel was an expense to be kept to a minimum. After quenching, a thicker plate should result in a hard top surface with some amount of natural tempering farther down due to the thermal mass. This would resist hard strikes better than a somewhat brittle, thinner plate.

However, the 'executive summary' of this thread is "don't miss"...LOL

R, I edited in light of your well placed comment:-)

[Rich Waugh]

Hollis,

Au contraire, mon ami. The executive summary is, "DO miss the anvil!" (big grin)

Hit the hot stuff and all is well; hit the cold anvil and all goes awry. From time to time, I wind up doing a bit of quick forging using the O/A torch for heat and my welding table (mild steel plate, 3/4" thick) as an anvil. Never marks it as long as I keep the hot iron between the hammer and the table.

I'm not advocating mild steel anvils though, don't get me wrong. I love my 250# Fisher. It has pretty much the mass required to just sit there, even when I'm using the 8# hand sledge for upsetting. I sure can't say that about the 112# Peter Wright.

One other thing that comes to mind is hammer hardness. There isn't any real need for a hammer face to be harder than a hardened anvil face. Hammers are much easier to dress than anvils. A slightly softer face will spall less and is less likely to skate off the striking end of a chisel or top tool.

[Ed Thomas]

Woody: You have exactly described almost all older anvils... "a slab of tool steel on a secure mount". The base of the anvil was welded in some manner to provide a secure platform for a steel plate. If you can duplicate the efficiency of that support some other way, then you have a decent anvil. Now, of course, it is cheaper and easier to cast or forge the entire anvil from some alloy and heat treat it so that the surface is the hardest part.

I am not sure what part of my post you misread to draw your conclusions from it.

[Glenn]

We have been talking about anvils, but what about the smithing hammer? Can you wear out a hammer from normal use?

Is the hammer face expected to mushroom out much like a chisel with use? How does the dressing of the hammer effect the working face? Does it need retempered after dressings, or several dressings?

[Woody]

In most of the old time blacksmith shop photos if you look at the anvil or anvils, they are fairly large in size. These old time smiths didn't have money to burn and probably weren't into a Freudian mine is bigger than yours contest mode. They were in business to make money and in doing so used the mose efficient tools available. They would not have purchased a big anvil for the bragging rites. Some seem to be more concerned with the surface damage that might be caused by an errant hammer blow than the internal structural damage that can be done by using a hammer that is too large for the anvil. Like I said I have knowledge of a anvil that weighed in excess of 100 lbs being broke from face to base into 2 pieces by people using a 10 lb sledge to work large pieces of metal on it. This was not a surface ding, the anvil was ruined completely. There is a definate corolation between hammer size and anvil size, it can be exceeded occasionally without harm, but if you pound steel on too small an anvil with too big a hammer too long, you are eventually going to do serious damage to the anvil regardless of how or what the anvil is mounted on even if you never miss the steel and hit the face of the anvil with a hammer.

[irnsrgn]

In all my years of attending blacksmith meetings in old time shops where the anvils were used on a daily basis for sharpening plow lays, and other work, usually 8 to 10 hours a day the anvils were in the 100 to 150 lb range. Only one shop had a large anvil, a 500 lber and it was a machine shop and light mfg business. My grandfathers one and only anvil is a 115 PW that I still have and he used a 4 lb hammer constantly on a daily basis for over 40 years . My father and uncles anvil a 150 lb trenton was used with a 4 lb hammer daily from 1941 untill my father died in 1979 and my uncle retired in 1980 and I bought his half. The anvil I use all the time is a 125 lb blackjack that I bought when a smith died and his shop was auctioned. and he used a 4 lb also. They all are in good shape. I guess they were the cream of the crop so to speak and extra care must have been taken in their manufacture. And also these anvils have had strikers working on them with 8,10 and 12 lb sledges.

Old timers were frugal with their spending and if they didn't do a lot of very large work were strikers where needed, they would not spend the money for a large anvil when a reasonable size would work.

[Chris Pook]

when you talk about oldtime shop the anvils you'd find here in North America and what you'd find in Europe are different story's.

An Friend of a good friend of mine who is a German trained blacksmith had his master give him a 350lb german patterned anvil from the 1800's when he finished his apprenticship and was going off to work in other shops.

I personally prefer the biggest anvil I can get, and am hoping to get a 600lb german patterened anvil my friend produces

[HWooldridge]

Glenn,

I definitely believe the hammer should be somewhat softer than the anvil for the reasons you cited.

My shop-built hammers are made from 1060 - only because I scrounged a good-sized, labelled drop some years ago at the scrap yard. I have experimented with several different styles and the one I now pick up almost always before the others is a square face, 2-1/2 lb, "French pattern". When making a hammer, I usually try to harden only the peen and face, while leaving the eye softer in the quench, then draw the whole thing to a purplish blue. This is harder than mild steel or even the 1060 as normalized but will dent slightly on the edge of the anvil if I miss with a hard blow. Over time, the edges will mushroom a bit so this hammer has been redressed twice in about 10 years. I also had the face spall a bit but it was a weird break, right in the center and almost like there was a small hidden pocket in the steel. It was only about 1/32" deep so I simply reground that spot. This break occurred in normal use, not because I was hitting chisels or missed the mark. In fact, I use a 4 lb, cast steel soft hammer for most of my set tools so the forging hammer is used only for that purpose.

[matt87]

It's often said that using too heavy a hammer on too small an anvil can/will damage the anvil. I've also heard that this is a myth. What is the truth to this? I have a 55lb double-horned hammer-welded anvil with a c.1inch thick steel face, am I likely to damage it by forging with a 4lb hammer? How about having a striker use a sledge? I'm not in the habit of forging iron cold. Does the anvil being welded-up or sold cast or forged steel affect things?

[Ian]

Matt, I pulled this from over the road at Anvilfire....

''Quote has been reworded:
The anvil and hammer should be of reasonable size for the work being done. A ratio of 1:50 hammer weight vs anvil weight is the norm. This translates into a 2 pound hammer for a 100 pound anvil."

part of a larger article on selecting an Anvil. It's an ineresting read.


I have deleted the quote from the Anvilfire site as Jock Dempsy of Anvilfire has stated that NO amount of material or text can be copied from Anvilfire and used on another site. I have however rewritten the material and inserted it as a reworded quote

[Dave Budd]

I didn't realise it was a damage thing. I thought that it was more about energy efficiency and the amount of bounce causd by a hammer versus the mass of the anvil?

[philip in china]

Amazing. A British posting with 2 British answers.

My understanding is that is to do with efficiency. It is possible to break an anvil but it happens very rarely. So don't use it if the temperature is very low- unless you warm it first. If you kake hardie tools put a collar on them so you aren't driving a wedge into the hole etc. Most of it is comon sense.

I suppose if you are using a small anvil with a big sledge ensuring the anvil is firmly anchored would be a help. That would stop it dancing around under the hamer blows. I use a couple of 280 pound anvils and can't imagine I am ever likely to break either o those!

[Glenn]

Hammer size vs Anvil Size
This is a previous discussion on the topic.

I have combined the two threads as they were on the same subject. Those who have not read the previous material should take the time to do so. It is an interesting discussion.

There is another thread on IForgeIron on anvil weight and the weight of the anvil stand, which is another interesting discussion. Use the forum search engine to find it and other related topics.


The IForgeIron archive.
When a new post is made to an old topic, that topic comes to the front for additional discussion. Many times we can combine two discussions on the same topic onto one thread with no loss of information. In this case the discussion was archived from July 2006 to Feb 2009 and now continues with a total of 39 posts in the discussion. You can read the entire discussion from beginning to end in one place.

[blksmth]

I realize this is a little late in this discussion, but here is my comment anyway: In answer to HWooldridge's post, the German Company in the article was the August Refflinghaus Co. They made the forge welded wrought iron anvils with a forge welded steel plate until about 1955. From then until about 1975 they used a cast steel body with a forge welded face plate. Since that time they make an all cast steel anvil and are of the opinion that it is the best anvil they have ever made as well as being cost effective. The article HWooldridge refers to was originally posted in the California Blacksmiths Association Magazine and has since been reproduced and published in Richard Postman's Book Anvils in America. Now the Ernst Refflinghaus Co. (Ernst Refflinghaus - Home) is still producing anvils using some of the same equipment and in the same location shown in the article, although much of the old equipment has been placed in a park for public viewing. Ernst Refflinghaus anvils can currently be purchased from the Shady Grove Blacksmith Shop, in the USA.

[Ian]

Having reread the entire thread I'm drawn to the following conclusion:


Although there is no true 'one size fits all' ratio for hammer vs anvil there is a definate and common sense approach that can be taken:

If it 'LOOKS' wrong, then chances are it 'IS' wrong. Your biggest concern should be ensuring the work and NOT the anvil takes a beating irrespective of the size of the hammer.

As for anvil size:

The function of an anvil (IMO) is to provide a SOLID and IMMOVABLE mass for hot steel to rest on whilst being struck with the hammer. This is important because the more immovable the mass in the anvil is the more kinetic energy can be imparted into the piece being worked.

You have to imagine the hot steel is acting as a shock absorber when struck, taking the kinetic energy from the hammer and deforming under the blow as energy is REFLECTED from the mass of the anvil back into the piece instead of moving through. Although some kinetic energy will be lost to the ground the larger portion will be used to deform the steel.

In theory if you had a section of 4'' square bar four feet long and buried it on end you would have a larger mass under your hammer than if you used an anvil on a stand with a 4'' face.

You'd move more on the square bar if everything else was equal.

A personal observation:

I was out in the yard today forging coat hooks on my 2cwt Brooks anvil. It stands on a composite wooden stump thats exactly the size of the anvils footprint. Where I work the ground is a little uneven and the anvil was rocking maybe a mm or so. I found that if I struck near the horn the anvil rocked a tad and rang a lot, but if I struck just off the middle of the face on the heel end it didn't rock at all and it barely tinged. In fact it produced a dull boom from the concrete the stump was resting on and my piece moved a lot more. Everything felt 'solid', exept the iron. I reckon thats what I should be after ALL the time.