Hank Rearden

Blacksmithing requires a knowing how to move the metal to achieve a desired result. You can drawl the metal, twist it, punch it and upset it to name a few. The pictures below shows a German pattern (top) and a Swedish pattern (bottom) Which one moves metal faster? Examine the photo. Both hammers weigh 1500 gm. or 3.3 lbs.  Assuming the same force is used  the Swedish hammer will move the metal faster. It has a small radius on the face the surface area is smaller. But the German hammer will also move the same amount. What's that you say? You've heard the saying in physics "for every action there is an equal reaction".  it applies here also. The smaller hammer moved a small area further than the German hammer but the German hammer moved more material, only less. If we measured it in molecules the same amount of molecules moved the same distance.  How to apply the results come from hitting hot metal a lot and learning how it reacts to the hammers blow. Also notice the necks of the from the center of the handle to the face of the hammer.  The distance The German hammer is shorter.  continue below image

hammer handle axis radius.png 

Imagine a X-axis up through the handle. We'll  call that the handle axis radius. In your hand that handle axis can rotate left or right. From the center of the axis to the face of the hammer. Let's call this the effective handle axis radius. Which is different than the radius of the hammer face radius itself.  Just know there are two ideas here. When using the German short pattern hammer and bringing down the hammer it twist a few degrees the hammers handle axis radius will be less off the bulls eye target of where you want the blow to land. Because of the shorter distance from the handle radius to the hammers face than if you used the Swedish pattern hammer instead. The example above shows two hammers each with a different handle axis radius.

The German short pattern will have less of the off target movement than the Swedish pattern hammer that has a larger handle axis radius.

Below are some more examples of hammer types

types of blacksmith hammers.png 


 Above left to right. Craftsman 3lbs sledge hammer, Picard German 3.3 lbs. short pattern, Picard Swedish 2.2 lbs. hammer, French pattern .75 lbs. hammer and a Diamond rounding hammer.


Below you can compare the hammers faces in the photos to the broad round face of the German short pattern.

picard german short and swedish pattern hammers.png

The smaller French pattern hammer has turned out to be an excellent hammer for me as I smooth out rougher forge marks because of it's flatter rectangular face. 

german short pattern and french hammer.png


german short pattern and diamond rounding hammer.png    

german short pattern and drill hammer.png 


  

Each hammer has it pros and cons on how it's used and the jobs it is best for in the hand of a blacksmith. Add to that the hammer blows can be more to the toe or heel or left or right edges, creating different results. As a blacksmith you may want to dress your hammer face so it is more universal as well.

Picard hammers are forged c45 steel with tempered faces and peens.


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Skarzs the Cave Troll
Cool information.
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Steve Meyer
Very nice to see them all lined out and the actual differences in one photo.
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Hank Rearden
The rounding hammer was one of the first hammer I got and thought now I'll get good at this because I thought I would move metal faster. I did. Only I moved it back and forth. A lot of work with out a lot of change. That's when I started working on techniques. Paying attention to how each hammer  was different and when a certain style hammer was best suited for the job.

To my surprise the small .75 lbs. French pattern hammer (copper colored hammer in photos) gets me the great results both in drawing out on the anvils edge and creating a smoother finish when used with the anvils face plate.  The face is rectangular and mostly flat with sharp radius edges.


Best of all I can hit fast and accurate because it's so light.  Note the drawing out is done with the larger hammers and the small French pattern hammer is more like clean up.
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jmccustomknives
As Hank just pointed out, control is king.  You can have a well made hammer but if it's to heavy for you to control it won't be as effective.  I have a lot of hammers, from 1lb cross peen to 10 lb sledge (yes, those are one handed).  My faves are the 3lbers, but I use them all.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Duce
In the second picture what is the hammer on the far right? I have 2 of those marked Bell System.
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Hank Rearden
That's a Diamond rounding hammer.
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Duce
Thanks. Now to some this maybe a foolish question, but here goes.
What is a rounding hammer used for?
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anvil
Good article, Hank. Here's my input.

First, I was a farrier for many years and the diamond rounding hammer was my hammer of choice, although I actually used the " flat face for most shaping.

In '79' I went to Turley Forge, and within the first few daze learned the difference in a rounding hammer and what I call a square cut, flat faced, forging hammer.

Square cut means its made, or forged to a square cross section. Flat face means just that,,,, with a small very important note. The face is slightly rounded and the edges are slightly bevelled. Technically this makes it a rounding hammer, but the "slightly" and the reason set the two apart. The reason is not to "round", concave in this case, but to keep from putting unwanted dings in your work. How flat and how much crown? Depends on your skill level and hammer control. Less is best as it moves iron best.

" Forging" means it is meant to change the cross section with greatest control and in the direction you chose. Thus I call this category of hammer forging hammers.

"Rounding" as the name implies means your hammers primary function is just that,,, to round. With the knowledge that we are not making a ball,,, we are forging a concave cross section or concave edge

So,, we blacksmiths are simple folk,,, we name our tools for their primary purpose. And I stress PRIMARY.

Let me explain why this is so.

Consider the most basic of the three blows we can make with our hammer on anvil,, the full faced blow. This blow is when the full face of the hammer strikes the center of the anvil and is parallel to the anvil face.

Imagine one good blow and its cross section.

A rounding hammer leaves a round concave depression

A square cut, flat faced leaves, for our purposes, a square depression with all the material within the same depth.

Let's look at control of direction.

Iron follows the path of least resistance always.

So the material moved by a rounding g hammer moves 360 degrees equally where a square cut hammer moves the material in only four directions(and a small amount on the diagonals). We are already gaining control of our material movement, the purpose of "forging".

Now let's add some basic hammer control and rotate the handle in your hand a bit. Now look at the cross section of each hammer blow.

The rounder is no longer round, its a crescent shape. Physics tells us that due to the shape there is one and only one single point that the force will move iron in a given direction. ( moment of force its called with,, simply stating two components or directions)

That's the center point and it moves forward the farthest and deepest. All other points on the crescent move in two directions,,, forewards and left(or right). These two " moments" add together and will equal the one single "moment" of the center point. The farther you go from the center, the "left" moment grows and the "forward" moment becomes less. Thus the leading edge is concave.

Now look at the same blow from the square cut, flat faced forging hammer.

The depression is no longer square, it becomes a line on the leading edge. Each point on this line moves equally forward,,, liberally. We still have a small amount of lateral movement on the edges, but very little as compared to a rounder. Thus our control of direction is greatest with this shape, or a flat faced cross peen.

Hope this answers the question.

So when do we use a rounder? A specialty tool. Well, its great on horse shoes for making those inside curves when needed.

As a blacksmith, consider say a tapered bar and you don't want straight sides? Think the Eiffel tower. A perfect job for a rounder.

I have three different rounders. Each a different diameter, one is square cut and they all have a different radius. Each fits a special purpose and are well used.

However my go to general forging hammer are my three square cut, flat faced, forging hammers.
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Hank Rearden
Thanks for the follow up "Anvil". I have a small French pattern hammer I enjoy using. "The copper colored one in the pics." It has a rectangular face that's relatively flat. I actually move metal very well with it. That was a surprise the first time used it. I used the rounded edge of my anvil as a fuller and the French pattern to forge. "I like the concept that your hammer is the anvil in you hand." I had more control and was able to drawl the metal out cleaner.

Know that you mentioned the square cut moment of force I'm going to study that the next time I'm forging.

Thanks for your input.
code[Maglio.gif]  Keep the fires burning hot!
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Scrambler82
Hank, Anvil,
Great write up, very informative, especially to a beginner !
Do It Right The First Time !
GrevB
Location: SoCal, USA
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Marc
Has anyone used a Japanese hammer? I never have and always wondered how you keep it from missing every time [smile]
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jmccustomknives
Marc wrote:
Has anyone used a Japanese hammer? I never have and always wondered how you keep it from missing every time [smile]


I feel the same way.  Supposed to make it easier to see what you are doing, but I think it would take a while to get used too.  I'm more concerned with how well it moved the metal.  lol.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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