what makes a Hofi Hammer so great

[ofafeather]

Can i make two observations without offending anyone? I have read and heard that the Hofi hammer is balanced because all the weight is the middle, how can this be when most of the middle is taken up by the large rectangular hole for the handle? Secondly, I have seen a video where someone is using a Hofi sledge hammer, how does the hammer/technique principal work here as the method of using a one handed forging hammer and a two handed sledge hammer are going to be completely different?

Ian,

It's not that all the weight is in the middle but more that the center of gravity or balance point is in the middle so that if you're working with the full face or pein the balance is the same. Many hammers are weight forward toward the face side which means that it naturally wants to pull straight down. This is useful for some things but not if you're angling the hammer to use the edges as fullers, or for other techniques. Hofi's technique is almost as if you were throwing the hammer - you use your fingers more to guide the hammer than to hold it and the grip is fairly loose. A weight forward hammer would require more grip for any blow angled to the sides.

With a sledge, the same principal applies in that with the center balance you can control the angle of delivery well. I believe most traditional sledges with 2 full faces are balanced that way. The difference is usually in a hammer that has a face and a pein because the mass is not equally distributed on both sides of the eye.

That's my understanding, at least.

[ofafeather]

The Hofi hammer is balanced because the weight of the hammer is distributed more equally on both sides of the eye, not because most of the weight is located in the center of the hammer head. Because of this you can tilt the hammer to the side much further than most any other hammer out there without it wanting to twist in your hand. When a hammer tries to twist in your hand you must counteract it with your wrist. This in turn puts pressure on your wrist and over years can cause problems. I have tested this with several hammers including the Sweedish hammer and there is no doubt that the Hofi hammer has much more control when it comes to rebound. Try it. Why is that important? Because if you think about it, most of the time you are not hammering straight down. You will tilt the hammer in order to lesson the amount of hammer head surface striking the material to in turn move more material.

On a side note. I have talked about what results from putting your thumb on top of the hammer handle.It causes nerve damage which runs up to your neck. I recently did a gate for a neuro-surgeon. We have become friends, he happens to live 2 minutes from me. He confirmed that placing your thumb on top of the hammer handle can in time cause this condition which would require surgery to correct and asked me if I had this problem. I explained how I hold the hammer and strike and he was impressed. I should not have that problem.

Guess our posts crossed - sorry to be redundant.

[Sam Thompson]

I didn't know they knew about or studied ergonomics and vectored physics three thousand years ago.

They didn't need bulls**t, they just got on with it.

[jimbob]

Guess our posts crossed - sorry to be redundant.

your leaving out the most important thing before each hammer leaves Hofi he gives it a Kiss!

[firebug]

your leaving out the most important thing before each hammer leaves Hofi he gives it a Kiss!

That is true. I have seen this personally. There is something about Hofi's saliva that re-aranges the molecular stucture of the steel alloy used in the hammer and also it seems to influence the very laws of physics as well as the space time continuum. {Shrug} I don't know it just works!

[Sam Thompson]

QED!

[firebug]

It has, been proven, I think!

[southernforge]

They didn't need bulls**t, they just got on with it.

There is a line of thought that there is two ways of having experience,
1,000 years of experience or one year of experience 1,000 times.

So the question is: If it is no longer possible to improve upon hammers and hammer techniques,
after how many years of experience did improving the process of hammering end?

Inquiring minds wonder. ;-)

[Sam Thompson]

And how much does it cost to find out?

[southernforge]

And how much does it cost to find out?

My apologies, from your post I concluded that you already knew the answer.

[Ramsberg]

It is not a balanced hammer, it is a hammer with a relatively well balanced head. If the head were square looking at it from the end and solid metal then it would be a "perfectly" balanced head.

A number of years ago I came up with the idea to make a balanced hammer, which I never got around to doing before I moved to a place that doesn't have a shop or provisions for installing one.

Anyways, I had come to the conclusion that a lot of the stress involved in swinging a hammer was produced by the hammer head having leverage on the hand, especially on the up swing. I tested this theory by holding a Babbitt hammer back wards in the same hand as my blacksmithing hammer. That way the heavier Babbitt head was on the opposite side of the hand as the lighter blacksmithing hammer head.

I must say that I was shocked by how much lighter the hammer felt even though the total load lifted was heavier. It is similar to holding one eight foot long 2 by 4 by its end, then doubling the weight by attaching another 2 by 4 to the end that you are holding, so that now you are holding it in the center of the load. Yes the two boards are heavier, but holding them in a balanced way will drastically lighten stress on all of the muscles used to counter the unbalanced load of the single board held by its end. In other words, the two boards could be held with a single finger if balanced in the center, the single board held by its end would require a lot of hand strength and stress to hold onto.

If anyone want to give this hammer idea a try, go for it. A chunk of Babbitt or something lagged into the hand end of the hammers handle would give a lot of balance, it wouldn't need to perfectly balance the head, just help out a bit.

Caleb Ramsby

[John B]

Sorry Caleb, I dont get it, if thats correct, why aren't we all using hammers with a head at each end, its a striking tool, not a twirling stick.

[maddog]

That's an interesting idea. My first thoughts are that having the head counterbalanced will rob the hammer of impact since its center of gravit will be behind the head. Also most of the handle flex will now be in the middle, where your hand is, rather than at the head.

If I understand it, Hofi's technique is to use the rebound, together with a bit of arm motion to rotate the hammer to vertical before lifting from the shoulder. Amit Harlev says about this that getting the hammer to vertical is the hardest part of the stroke. So they seem to agree with you on the main issues in lifting the hammer for a strike.

The blocky shape of the hofi hammer makes it easier to tilt since the mass is compact and also helps to keep the center of gravity above the face when using the edges to fuller.

[Ramsberg]

Hey Maddog,

The force of the hammer strike comes from the inertia of the hammer head, having a ball of babbitt on the other end won't change the inertia of the swung head, so the force of the strike would be the same.

You are right, the rebound of the hammer off of a strong strike should be utilized as much as possible to lift the hammer head.

Think though about how many lift you make of the hammer that are "dead", that is when you are returning to the anvil or after carefully changing the position of the stock that you are working on. Then you have no rebound to lift the hammer, so there is a lot of stress produced by lifting the hammer head on the unbalanced stick.

I wrote Hofi a note about this a year or so back, he didn't like it, to each his own.

Hey John,

I don't know, maybe because it is a bad idea! It could also be that other people have tried and used it before and liked it, but it didn't spread and "take". It is an idea that in ones mind seems very counterintuitive, but the effect in ones hand is very different.

I did the same thing with a very large and heavy fire hook that I made many years back. It was made in three parts, the hook, a three foot section(after hooking it) of 1 1/4" round stock, then two bits of black pipe with their ends flattened and then the handle another three foot section of heavy round stock squared in the middle with some twists. When it was bolted together it was over ten feet long and very difficult to hold by the handle, because of the leverage involved and unbalance of weight. So then I attached some cast iron window weights to the end of the handle(about 25 lbs worth) and the extra weight made the thing much more manageable. Every one called me crazy for ADDING weight to the hook saying that it was already too heavy, but when they tried it out, they agreed that it FELT lighter.

When I had a forge and was blacksmithing I found that the first muscles in my body to tire were my forearms, not my back, shoulders or upper arms, but my forearms. So I decided to investigate and using a dumbbell as practice decided to see what wore out first while I made the same arc of swing that I did with the hammer. My forearm didn't even get tired at all and I had to go to a much, much heavier weight then the hammer to get the same rate of muscle fatigue that the hammer gave me. That experiment pointed out to me the impact that the unbalanced stick(aka. hammer) was having on my body. You will notice that the people using the "Hofi" technique are all griping the hammer rather close to the hammer head, thusly decreasing the leverage that the hammer head has on their hand.

Ahh, it is just an idea, I am not going to try and convert anyone to any given system. Everyone should do things in their own way. . . otherwise the world would be a VERY boring place!

Just having some fun and puting an idea out there.

Caleb Ramsby

[Nakedanvil - Grant Sarver]

Sound like an easy enough experiment to try. I like the way you think Caleb! Actually it's not a different way of thinking, it's just actually thinking..........a lot. I've never found anything wrong with this guys logic. Well, thought I did once, but he educated me and now I listen when he talks. I'll play with it and see what I think.

[Marc]

This topic has gotten interesting. I, too, find my forearms are the parts that get tired. One thing about the counterbalance - When the hammer head hits the steel, it stops, but the counterweight will want to continue. So now you're hand/arm has got to reverse that direction. Still, as Grant says, this is easy enough to experiment with.

[Nakedanvil - Grant Sarver]

Marc: I don't see too much problem there. Your wrist is the last thing to rotate as you swing down, so, being a counter-lever (hmm, must be where cantilever comes from) it's going up relative to your wrist while your arm is coming down, so it probably is not moving much relative to the world.

[Nakedanvil - Grant Sarver]

A similar thing is when you use a small sledge as a hand hammer. Easy enough to bring down, but you would have a hard time raising it with your wrist if it had a short handle. So what I end up doing is letting the long handle extend back so it comes up under my elbow. Now this tells me that Rambsurg's analysis is spot on - my arm can lift the hammer, it's my wrist that has a problem.

[Ramsberg]

Hey Grant,

I like the way that you think too. . . with your brain! HA! It's fun to have fun.

Have fun with the idea, I am rather ashamed that I have never gotten around to doing anything with it, as you said, not that difficult of a project.

Hey Marc,

I think that it depends on the specific swing that one is using, if as Grant says it has a whip of the wrist at its end then the counterweight may actually be rotating up. Anytime the head rotates down then the counterweight will rotate up, so at the point of impact the inertia of the counterweight may actually be trying to lift your hand, which could be usefull.

One thing that I am very curious about is what will happen to the vibrations of the hammer. My experiences with musical instruments tells me that it will probably be deadened by the counterweight. . . especially if a metal rod went through a hollow wooden handle from the head to the counterweight. That of course would complicate the hammer construction a bit and possibly weaken the handle, but it's an idea.

Caleb Ramsby

[divermike]

well in my opinion this is a simple topic to answer, if you like it, it's great and you will use it. If you don't like it, it sucks and you will not. I personally love a short handled hammer, and the shape of the handle is very important to your grip fatigue. As to the swing, his explanation of the mechanics works very well for me, but I had discovered it before I had seen his video, I was taught some martial arts in my younger days, and the cobra strike mechanics teach essentially the same context, the fist is a rock on a stick, but if the stick rotates the head prior to strike, it essentally adds a significant amount of velocity to the strike, and as Mark Aspery explained in a class very well, mass increased with velocity, is better than extra mass, or something like that, in any event, I do not own a Hofi hammer, just a short handled 2 pound cross peen, which is the first hammer I ever forged with, and it seems to make my hand happy, so I stick with it. Although occasionally I will pull out my french pattern 2 pounder with a longer handle, David Robinson uses this type, and got me to trying it. I guess being somewhat relaxed during the forging process is almost just as important, I tend to clench up, if you catch my drift, and just do a better job, with less stress, when I remind myself to relax and let the tools do the work.

[John McPherson]

Grant struck a chord with his observation about a cantilever. Many experienced smiths will tell you that you *have* to use hammer handles as long as your forearm, and hold it by the very end. (One of the many things St. Francis scolded his students about.) But action shots at the anvil almost always show them holding the hammer mid-way down the handle. (Unscientific survey of the gallery here.)

Try if for yourself. Clean up the handle of your favorite forging hammer, get some dirt on your hand, and forge something. See where the dirt ends up.

[fciron]

I noticed I wasn't using the last four inches on most of my hammers so I cut them off. Exactly the opposite of Ramsberg's Modest Proposal, but I prefer them that way.

I do have a box of old hammers. I am gonna make up a double header and try this experiment soon.

[Marc]

I hadn't thought about that whip at the end of the blow. That would rotate the counterweight up and actually add some force to the blow. I have gotten used to the short handle and forged a hammer to the same dimensions as Hofi's, who was nice enough to email me those dimensions. So I think I'll test this counterweight concept with a long-handled hammer. I'll keep my grip choked up so that the counterweight has more leverage and see if my forearms wimp out as fast. I'm a perfect test subject for this. I don't get in the shop nearly often enough to build up endurance, so I'll know in about an hour if it makes a difference.

[Ramsberg]

Hi All,

I can't wait to hear about all of the different versions of the double headed/counterweighted/balanced hammer that you all come up with and the almost assuredly mixed bag of results that arise from them!

I hope that at the least you all enjoy the experimentation with the idea as much as I do the sharing of it!

Sometimes I wonder how the "closed clan" blacksmiths of many years ago would view our ability and willingness to share ideas and techniques. At that time it was in their best interest to keep things under the wrap of "trade secrets" as did the practitioners of almost all of the many trades. Here(in regards to this website) there seems to be a lot more hobby people then business blacksmiths and I doubt that many of the businesses compete head to head in regards to big contracts, so an openness makes a lot more sense.

When my great-grandfather had his blacksmith shop, his(employing three to five people) was one of SEVEN in a relatively small city, Kirkland, Illinois, now a village. Getting off track now.

Caleb Ramsby

[John McPherson]

Ramsberg's idea may not be too far off. A pommel nut on a sword is only a few ounces, but changes the point of balance significantly.

I have tried using a ball peen hammer that came with a severely shortened handle, and just found it clunky.

Blacksmiths swing their hammers a LOT more than a warrior swings a sword, I wonder if anyone ever tried pommel nuts on hammers in antiquity, and was just told "We don't do that here."

Peer pressure is a real force. An Americanized carpenter went back to his old home town in Europe, and his cousins laughed and threw nails at him until he put away his black Titanium hammer and nylon toolbelt, and used the old style.