Hammer Shape and Its Effect on Precision

[JHCC]

The following discussion began as comments on photos I posted about a new, rather slender rounding hammer I'd just finished.

4 hours ago, C-1ToolSteel said:

As far as precision goes, I have always preferred a farrier style hammer, because the faces are extra close to the eye (if you turn your wrist a tad, the consequenses are much more subtle than with a really long face). Thoughts?

2 hours ago, jlpservicesinc said:

I’ve personally found this type of hammer for general forging to be a little more taxing on the wrist as it needs more stabilization at the handle on impact thus wanting to twist the head with each hit..  

It seems to me that if we analyze this question, it really comes down to two important angles: the angle of the face of the hammer and the angle of the path of the hammer strike, both measured relative to the workpiece. For example, in the first these two drawings, the face of the hammer is parallel to the workpiece, but the path is different.

Here, the hammer is angled, but the paths are again different. 

With each of these, the metal will generally move in the direction of the hammer blow, with the angle of the hammer face having a secondary effect on its flow. 

As far as precision goes, a longer, thinner hammer both will have a smaller striking area and will be easier to aim.

However, unless the path of the hammer blow is precisely aligned with the long axis of the head, there will be more torque on the handle. In other words, the mass of the hammer head and the force of the blow will combine to form a lever with the impact point as the fulcrum. 

Whereas with a shorter, fatter hammer (like a farrier’s rounding hammer), the center of mass is going to be closer to the point of impact, creating a shorter lever with less torque. 

In sum, the longer, narrower hammer would theoretically be better for delivering at targeted blows at precise angles, so long as the path of the hammer head is in line with its long axis. The shorter, thicker hammer can strike along a variety of paths and would be more forgiving of hitting off-center or off-axis. 

Thoughts?

[Charles R. Stevens]

Pictures of two crosspeins to ilistrate your point

 

The degree of crown also effects the sense that the hammer is trying to twist as well. My rounding hammers came dead flat, and were very hard on the risks and contributed to a death grip as they jumped if the blow was the slightest off center. 

[Frosty]

OOH good subject John well done! I can just feel some good well thought out arguments brewing! My kind of discussions. 

Your second drawing is a good illustration of a common myth.  This kind of striking is a huge waste of effort and energy EXCEPT for smal small final corrections in specific conditions. Say unrolling a curled edge rather than just filing or grinding. This is my opinion based on personal experience and observation and is NOT a set in stone rule. 

I have other experiences and observations of course, yesterday's club demonstration being a perfect example of using the right for the desired results and how proper preforms make BIG differences. 

Frosty The Lucky.

[jlpservicesinc]

Yes, what you wrote is a "Yes"... 

 

Here becomes the problem...     If you only use the hammer in a direct up and down motion..  This doesn't mean a straight line of flight.. This means keep the hammer in line during a hit..  Or keeping the hammers mass in line over the complete arc so the hammer hits in line or in other words.. It has to travel with the energy traveling completely through the center line of the hammer to prevent a twisting or leveraging of the hammer handle.. 

Which you shown excellently in your drawings.. "Thanks you very much".. Drop MIc""        This longer style hammer needs to have a consistent force in line with the hammers length.. 

This leveraging effect can take it's toll in the wrists and hands to stabilize this action..  And was what I found.. But..

And since as a Blacksmith I rarely hit the metal ever in line with the mass it didn't work for me..    I always swing my hammer in the direction I want the metal to move..  or with a heel, peen, or side of a angled face..  

All the smiths I have seen today  at meets, Youtube..etc etc.  Always move the hammer straight up and down.. (arc or no arc its still up and down with no lateral movement of the hammers face or peen) Unless hitting or chasing a top tool or the like..  I'm not saying people don't do it..  But I have seen videos where the guys are telling everybody not to do it..   Wrong..       Drawing a clip on a horse shoe is an example as is the video on forging tapers..  

In the last taper video I show pictures of which way the hammer is moving and in terms of off angle hammer strikes against (left/right) vs fore/aft is where for me the problem come in.. 

The longer hammer can in theory have a more effective hit because there is more mass in line vs that of a shorter hammer which is more squaty..  this means if it is not in line it will want to twist more away from the pivot point which for all intensive purposes is the handles eye and handle since your hand is grabbing it.. 

My reference with angling of the anvils face was down and away thus creating a level left to right but lets the hammer fully drop with still being in line with the natural arc or the swing for the longer area away from the eye..   

A lot of the Japanese hammers have the shafts bent at a 45degree or so because the anvil is mounted on the ground..  Kind of the same thing but different.. 


As for accuracy of a hammer blow..     It's not that a narrow hammer will be more accurate in swinging it, it is the fact that it will cover less material or effect less material as the face is smaller,  it is also that the force will be directed into the work differently..  

A smaller hammer will also allow for a person to choose a target more easily with ones MIND because the larger hammer will obscure more of what we see when we hit vs the narrower and longer hammer..  

I always split a hammers face into 8 quadrants..  Front, heel, left, right, front left, front right, heel left, heel right...   Each of these can be used to good merit or differently based on how one swings a hammer.. 

Accuracy with a hammer at the anvil can be constrained into 3 categories really..   (yes there are more, but these are the 3 that I see needing to be dealt with the most)

Repeat blow accuracy:   This is where the first blow is delivered and then we adjust the accuracy with the second or even 3rd blow.. 

 

Bio mechanical Accuracy:   This is where you position your body and use your skeletal limitations to deliver the blow..   Bent elbow, tucked into your rib cage. back straight.. Each blow will fall exactly each time if you keep everything in the right position..  (yes there are variations but its the feedback from the body)

Eye, hand Accuracy: This is where one trains the body to see the target and then with enough training accurately hit that target...  


Then lastly:: : WE look at the combining of all of these...  This separates out a lot of how people swing a hammer as there are thousands of variations. LOL.. 

I can't hit a carpentry nail when framing a wall to save my life.. Yet can hit a number 3 slim shank race nail with a hammer that only has a 3/8" X 3/8" face. upside down and backwards with nailing on an aluminum Race plate on a moving horse.  This is because I am using the skeletal method mentioned above.. 

At the anvil because I swing a hammer in many directions and pull or push the hammer as it swings it completely changes the effect or how these methods take place..  Being skilled at all is what it takes to be effective and efficient..    

learning methods that take into consideration how your body moves can help substantially..  

In one of the videos I talk about moving my left arm under to my right hip with the metal on the anvil so my swing with the right hand is now locked into my body.. 

30 minutes ago, Frosty said:

OOH good subject John well done! I can just feel some good well thought out arguments brewing! My kind of discussions. 

Your second drawing is a good illustration of a common myth.  This kind of striking is a huge waste of effort and energy EXCEPT for smal small final corrections in specific conditions. Say unrolling a curled edge rather than just filing or grinding. This is my opinion based on personal experience and observation and is NOT a set in stone rule. 

I have other experiences and observations of course, yesterday's club demonstration being a perfect example of using the right for the desired results and how proper preforms make BIG differences. 

Frosty The Lucky.

I disagree Frosty...     Its the reason we all have a strong side vs a weak side when we work with a hammer..    I'm sure over the years you have noticed that if you simply swing the hammer there will always be a side that seems to draw out more easily like when making leaves or bevels and such....  

Again, i always forge or I should say 90% of the time I forge with moving the hammer in the direction I want to the metal to move....  

John On the 2 long pictures..   Both would render the same results as  in hammer deflection at the handle...    I personally would have to swing at a complete angle to the work and anvil to keep the mass of the hammer in a long enough geometry to deliver, recover and swing again which would be nearly at a complete diagonal.. 

This for moving metal would be a tough venture even double jointed..   Now If I were laying on my side with a spacer to have enough arm room it might work.... 

 

Frosty.. If the hammer face were completely flat to the metal in picture 2 or if the angle of pull was not appropriate than I would agree.. 

[jeremy k]

This is a great subject - although - before one can pick apart the mechanics of hammer position and angle - one first has to have a very accurate hammer control (muscle memory) from lots of hammering. Once someone has a definite consistent hammer control, then they can improve by seeing the problems from that initial consistency, and only then can change things to improve their hammer control. Do keep the topic in controversy!!!!

[Charles R. Stevens]

If that framing nail was moving you would hit it every time...

[JHCC]

26 minutes ago, jlpservicesinc said:

The longer hammer can in theory have a more effective hit because there is more mass in line vs that of a shorter hammer which is more squaty.

In other words, the force exerted by the hammer blow follows the rule for pressure: mass divided by area. A 2 lb hammer with a 1" square face and a 2 lb. hammer with a 4" square face will both hit with the same total force, but the hammer with the smaller face will have that impact concentrated on an area 1/4 the size of the larger.

[jlpservicesinc]

24 minutes ago, JHCC said:

In other words, the force exerted by the hammer blow follows the rule for pressure: mass divided by area. A 2 lb hammer with a 1" square face and a 2 lb. hammer with a 4" square face will both hit with the same total force, but the hammer with the smaller face will have that impact concentrated on an area 1/4 the size of the larger.

Yes and no.. Since we are not machines and we never have a consistent output..    We only can put out a general sense of what is really being generated....   When working with students in martial arts I show them the difference between the power of a training punch which is about 3% of what I can produce total.. this is enough to make them sit in a chair and even the biggest guys to rethink  what or how..  Yet to generate a punch at 100% power even if it is all I practiced at for 10 years would only be able to achieve 100% power, maybe 3% of the time in full motion sparring..  The variables are just to large..   At the anvil I rarely if ever get to just stand in one spot and swing a hammer as hard as I can..   If its not because of  metal width/thickness requirements, it's because I simply can't keep it up..  With this accuracy becomes key..  

it's not just the swing of the hammer that equals the work produced...    Heat, metal type,  cross section,  hammer size, anvil size vs effective ratio...    Accuracy of the hammer blow becomes the true metal mover...    It's one of the reasons  1/2 on 1/2 off works so well.. there is a bunch of room for mistakes...  It eliminates having to be accurate as working at a deep shoulder..    or making a tang like in the Ladle video...  Forging a 4" wide plate, pulling off a 2" section without creating a cold shut or peeling off a sliver into the main part and keeping it centered... 

This is where fuller come in..   Or do they??  Power hammer perhaps? 

Hammer accuracy, endurance while swinging a given hammer.  Understanding how or why you are hitting it where you are hitting it and how that will effect where it is hit next playing into a larger segment..    

A skilled smith can make with very few tools what an unskilled smith would need in a fully equipped shop.. 

I never bring my own hammers to someone elses shop when I go to help...   I use what ever is there..   Same with forge, vises, anvils... .   The quality of work is about the person doing it..   Not the tooling...  With this said, I will also make suggestions as to what they might find better or easier..

Good tools  are always a work and time saver... But, working when things are not ideal can show where a persons skill set could use a little be more tidying..  

 

You could look at the mass in a narrow hammer a lot like a ball bearing test.. Or putting a rail road track upright vs on it's side...  

Again the problem I had or have is that length just plays havoc with my wrists..   I have a 12" long leaf hammer which is designed properly and if I use it for to long it also bothers my wrists.. 

 

[jlpservicesinc]

If this is the type of hammer your Mentor is using.. Go for it...   It's time like these that can make a golden memory..  And to be taken under someones wing that is knowledgeable and willing to show it to you is awesome..  

[jlpservicesinc]

1 hour ago, jeremy k said:

This is a great subject - although - before one can pick apart the mechanics of hammer position and angle - one first has to have a very accurate hammer control (muscle memory) from lots of hammering. Once someone has a definite consistent hammer control, then they can improve by seeing the problems from that initial consistency, and only then can change things to improve their hammer control. Do keep the topic in controversy!!!!

Accuracy is the shaa bang...  of forging..  

I think this is where..  An up and down motion only in the hammer can lead to better accuracy for newer smiths as they make these adjustments... I could barely swing the 2.5lbs hammer more than just a few strikes at a time when I started.. I was very much a hit straight person as the hammer was wild... You could be over at the neighbors house and you'd have to duck when i was forging...         It took me maybe 7 years or so to start to seeing the advantages to hitting in directions vs just up and down.. 
 

1 hour ago, Charles R. Stevens said:

If that framing nail was moving you would hit it every time...

LOL.   

I knew a carpenter who could sink a 16Penny  framing nail in 3 whacks  each and every time.. Yet he could never hit the same spot twice when forging..  One time he threw the 2lbs hammer I let him borrow across the shop.. That was the last time he forged, he was so angry about the whole thing..    Still makes me chuckle.. He was so upset about it..   

As pointed out the hammer face shape, as well as flat vs crowned vs  rounded head to heel (like in swedish hammers) plays in..   Some nice hammers there.. What does the Cats eye weigh?   Is this your clipping hammer?   I had seen an old one that had a peen on the side of it also...  What is the measurements on that Colonial? 

[JHCC]

39 minutes ago, jlpservicesinc said:

If this is the type of hammer your Mentor is using.. Go for it...   It's time like these that can make a golden memory..  And to be taken under someones wing that is knowledgeable and willing to show it to you is awesome..  

 Well, that was 35 years ago, and I may be fuzzy on the details.  The proportions are about the same, but I think Fred’s was a cross peen. 

[Charles R. Stevens]

The cats eye and rounding hammer weigh in at 3# handled wile the long cross pein weighs in at 2 1/2#. Have no idea what it was originally, it’s a Asian made hammer or good steel and respectable hardness.I found it on a used tool dealers truck with a loos handle for $5. Reset the handle and off we went. 

[MC Hammer]

This is pretty interesting.  Being a flintknapper, I have been able to master swinging a percussion tool and hitting a rather small area consistently to remove flakes to make a sharp blade..  Shifting to blacksmithing didn't  pose a problem hitting where I intended and in fact I thought it was oh so much better because if I hit the hot iron in the wrong place or the results weren't what I wanted I can just reheat the metal and do it again.  In flintknapping, a wrongly placed hit can cause irreparable damage, break the piece entirely, or take off material you can't put back on.  I say all this because I think it is relevant here on two points:  1)  hand eye coordination is vital in blacksmithing.  We may feel that is a "duh" point, but those that lack it will suffer learning to move metal.  2)  The master flintknappers I learned from always told me that you never change the angle of your swing and that it must remain a consistent arc and that you change only the angle of the piece of flint you are holding.  I've learned that is not true and my masters still shake their heads when I adjust the angle of my swing to project the force of the strike a different direction through the flint.  One of those things where I learned the rules so well I could see where they could be broken to gain better results.  I think JLP is making that point in some degree in the fact that you change the angle of the hammer to move metal in different directions.  

I also second JLP's notion about the efficiency of experience.  The master flintknappers I've known can take many fewer flakes to achieve a better looking result than someone with much less experience.  Slow is smooth and smooth is fast.  Making each hammer blow to it's near full work potential saves time, energy, and wear / tear on the the body.  I've always felt crafts like blacksmithing, flintknapping and the likes are of the vein of working smarter and not working harder.  That notion is hard to teach the younger generations that never popped popcorn on the stove or reheated food in the oven or had to get up to turn the channel on the TV.

 

[ThomasPowers]

Note two that folks generally talk about this flat on flat,  When you start working curved pieces then the hammer starts being used in odd directions.  Lets say you want to dish the bottom of an old fire extinguisher tank about 6" across and 6" deep---probably can't reach the bottom with the cat head hammer...

Armourmaking is a great excuse for collecting hammers---the one that's good for peening rivets in the top part of a spangen helm is NOT the one for forging out a breast plate!

[Frosty]

Perhaps I misinterpreted the sketch I referenced.  I was not talking about angling the hammer to match the face of the piece being forged nor the direction of the blow. A person would have a lot of trouble drawing a taper if they tried keeping the hammer face parallel to the anvil. I've never considered that thought to be serious enough to address, it's frankly silly.

What I was referring to is the intuitive thought that striking a glancing blow somehow makes the steel move in the direction the hammer is sliding. Pushing or pulling the hammer so it glances towards the edge of a bevel is wasting energy. 

A basic principle of forging is, Any steel not backed by the anvil is bent not forged. Glancing or sliding blows are directing energy along the surface rather than into the stock. Any movement of the stock by this action if ANY would be more properly called galling. Laying a rolled edge flat is bending rather than changing the material's thickness. It is not By definition forging.

Steel is forged by PSI. Of course a smaller contact area for the same given weight and velocity of the hammer moves THAT area of stock farther. Come ON folks, this is BASIC physics! Do you need to be told why swords are pointy on ONE end and why you don't hold THAT end?

Who thought THAT needed arguing? It's frankly embarrassing. Remember boys and girls push on the BIG end of the thumb tack!

Rounding hammer peins move steel more efficiently than the face because the initial impact point is minute compared to the diameter of the hammer. Just to be clear, for the purpose of discussion I use Pein to delineate the shaped side of a hammer or top too. Conversely I use Face to delineate the "flat" side.  

A cross or straight pein acts like a wedge in the steel. The radiused contact point is a tiny % of the total cross section so it penetrates much more effectively and as it does it directs the movement of the plastic steel mostly in two directions 180* opposed. The smaller the radius the deeper and narrower the groove it makes. It allows more control to the user in directing the direction the material moves. Taken to one extreme is a chisel or scalpel edge, the other extreme is the large end of an anvil's horn. Top and bottom fullers come or are made in many radii. We radius the edges of our anvils to prevent them from cutting the piece being worked and to allow us to shoulder a piece with precision.

A ball pein moves the material in 360* but more deeply than the face because it's impact point is a VERY small % of the overall hammer dia. so the PSI is huge. Think of them like an extreme rounding hammer, they work the same way they just effect a smaller area so the impact crater is smaller dia. but deeper requiring ore work to smooth it out for the desired finished surface.

Frosty The Lucky.

[JHCC]

2 minutes ago, Frosty said:

Remember boys and girls push on the BIG end of the thumb tack!

If only I'd learned this sooner, how many fewer punctures I might have had on my thumbs!

[jlpservicesinc]

6 hours ago, Frosty said:

Perhaps I misinterpreted the sketch I referenced.  I was not talking about angling the hammer to match the face of the piece being forged nor the direction of the blow. A person would have a lot of trouble drawing a taper if they tried keeping the hammer face parallel to the anvil. I've never considered that thought to be serious enough to address, it's frankly silly.

What I was referring to is the intuitive thought that striking a glancing blow somehow makes the steel move in the direction the hammer is sliding. Pushing or pulling the hammer so it glances towards the edge of a bevel is wasting energy. 

A basic principle of forging is, Any steel not backed by the anvil is bent not forged. Glancing or sliding blows are directing energy along the surface rather than into the stock. Any movement of the stock by this action if ANY would be more properly called galling. Laying a rolled edge flat is bending rather than changing the material's thickness. It is not By definition forging.

Steel is forged by PSI. Of course a smaller contact area for the same given weight and velocity of the hammer moves THAT area of stock farther. Come ON folks, this is BASIC physics! Do you need to be told why swords are pointy on ONE end and why you don't hold THAT end?

Who thought THAT needed arguing? It's frankly embarrassing. Remember boys and girls push on the BIG end of the thumb tack!

Rounding hammer peins move steel more efficiently than the face because the initial impact point is minute compared to the diameter of the hammer. Just to be clear, for the purpose of discussion I use Pein to delineate the shaped side of a hammer or top too. Conversely I use Face to delineate the "flat" side.  

A cross or straight pein acts like a wedge in the steel. The radiused contact point is a tiny % of the total cross section so it penetrates much more effectively and as it does it directs the movement of the plastic steel mostly in two directions 180* opposed. The smaller the radius the deeper and narrower the groove it makes. It allows more control to the user in directing the direction the material moves. Taken to one extreme is a chisel or scalpel edge, the other extreme is the large end of an anvil's horn. Top and bottom fullers come or are made in many radii. We radius the edges of our anvils to prevent them from cutting the piece being worked and to allow us to shoulder a piece with precision.

A ball pein moves the material in 360* but more deeply than the face because it's impact point is a VERY small % of the overall hammer dia. so the PSI is huge. Think of them like an extreme rounding hammer, they work the same way they just effect a smaller area so the impact crater is smaller dia. but deeper requiring ore work to smooth it out for the desired finished surface.

Frosty The Lucky.

I totally disagree... With your statement.. It's not just physics.. And its also not just PSI..    As humans don't produce that way.. Or register in PSI when they work metal..  If it were so, big strong guys would always move more metal no matter what their skill set is..  

Foolish is, or believes as foolish does and the concept that a glancing blow does little can be foolish..   This statement is in reference to believing something is so because of never having seen it else where.. 

I wrote a whole response to your statement and then deleted it all....  It comes down to believing what ever you choose... I feel badly that someone would take on such a limited view of a skill set that is useful..  

I gave to examples of such a use with the video and they speak for themselves..   I planned on doing a peening video or directional forging before this thread was started but after your comment I went out and did a few directional peening sessions...  This wasn't about making a finished product.. Just to move the metal only in 1 direction with no correct or starting with an offset shoulder to skew the results.. 

These were drawn with the peen of a hammer..  4 different hammers all with a pulling motion to the stronger side.. My stronger side which is towards me... 

Again, you can use your physics or your PSI formula but when you need to move the metal in only 1 direction it moves faster if you pull the metal into place... 

Normal peening will not get you the results in these photos..      They were all thinned evenly.. You can see the difference with the different weight hammers.. The top one was done with a 900gram swedish cross peen.. this was peened on the uphill side first and then the metal was pulled the opposite direction..     1/4 X 1.25" 1018 HR was the starting material.. 

These examples were simply done on the end of a bar  and the width was 1.25 which is the metal width.. Thus I pulled the 1.25 out of the parent bar.. The length will be in the video, but the top 1 was only 3/4" to the right side of the bar with nearly 2.5 " pulled out of it..  

 

[Frosty]

7 hours ago, jlpservicesinc said:

I totally disagree... With your statement.. It's not just physics.. And its also not just PSI..    As humans don't produce that way.. Or register in PSI when they work metal..  If it were so, big strong guys would always move more metal no matter what their skill set is..  

Foolish is, or believes as foolish does and the concept that a glancing blow does little can be foolish..   This statement is in reference to believing something is so because of never having seen it else where.. 

I wrote a whole response to your statement and then deleted it all....  It comes down to believing what ever you choose... I feel badly that someone would take on such a limited view of a skill set that is useful..  

I gave to examples of such a use with the video and they speak for themselves..   I planned on doing a peening video or directional forging before this thread was started but after your comment I went out and did a few directional peening sessions...  This wasn't about making a finished product.. Just to move the metal only in 1 direction with no correct or starting with an offset shoulder to skew the results.. 

These were drawn with the peen of a hammer..  4 different hammers all with a pulling motion to the stronger side.. My stronger side which is towards me... 

Again, you can use your physics or your PSI formula but when you need to move the metal in only 1 direction it moves faster if you pull the metal into place... 

Normal peening will not get you the results in these photos..      They were all thinned evenly.. You can see the difference with the different weight hammers.. The top one was done with a 900gram swedish cross peen.. this was peened on the uphill side first and then the metal was pulled the opposite direction..     1/4 X 1.25" 1018 HR was the starting material.. 

These examples were simply done on the end of a bar  and the width was 1.25 which is the metal width.. Thus I pulled the 1.25 out of the parent bar.. The length will be in the video, but the top 1 was only 3/4" to the right side of the bar with nearly 2.5 " pulled out of it..  

You totally disagree so you credit NOTHING I said as right? Either you don't understand my statements or you're deliberately misunderstanding. I'll give you the benefit of the doubt that I did't express myself clearly enough. Deliberately misunderstanding someone makes a point the user of thee tactic really doesn't want to make.

The effects of the forces we apply to make steel do our bidding is simple physics. PERIOD. How we use physics is the art of the human mind and thumbs. Blacksmithing is as good a demonstration of simply physics as there is. Pointing out different people operate differently is obvious to the point of being facetious. It's also a Non sequitur. My statement was solely about how a hammer moves metal, not differences in human behavior or beliefs.

You like to draw on your martial skills for examples. Let's draw an analogy. We're forced into a fight, not kata, not tournament, we're facing someone meaning to do us harm and we've exhausted other means to deal. This isn't a demonstration this is combat. With me so far? 

In our dojos we learned self defense, we spared, fought in tournaments, point and full contact but in essence it was a self defense club. The main components or Ryo Dojo martial arts was Shoto Kahn and Kempo. Kempo for the round fluid motions, it's an excellent blocking style and we combined it with Shoto Kahn for it's straight in smash and destroy strength. After the first two tournaments the Parker schools wouldn't fight us. Shoto Kahn blocks tended to be brute strength move where Kempo were deflection  with the least movement and strength to make a blow miss.

I speak of both in the past tense because it's a good 40 years since I practiced and I no longer consider myself a karateka though I can still do some of the basics.

Sorry for the long sidetrack perhaps I'd just like you to know I know of what I speak, I practiced the arts for years. We're back to a real life combat situation and a larger opponent  Is going to require real damage to stop. I reflexively select my opening which happens to be a straight in two knuckle punch to the sternum. Do I follow my understanding of simple physics and punch him driving for his spine. OR do I use a glancing blow?

What would sensei say?  Mine would've visited me in the hospital and guaranteed I'd be punching the makawari boards till my feet bled for being such a. How'd you put it.  "Foolish believes or foolish does." I believe you said?

Not once did I suggest a blow should not impact at an angle. I'm not a novice I know how to direct the steel in one direction and it is NOT by letting the hammer slide across the steel in the direction I'd LIKE it to go. Please select the pic you posted that best shows evidence  your pein slid across the steel. Go ahead SHOW ME.

Perhaps our only real difference is semantic, when you say push or pull a blow you mean angle a blow away or towards yourself.  I do that and frequently, in fact it was a large part of the demo I did for the club last Saturday, I just screwed up and brought the wrong cross pein. My bad my demo of directional forging wasn't so hot. Fortunately the request was to see a socket rolled.

I screw up all the time, I just do my best to not waste effort.  Then again I'm not nearly as strong physically as you are nor am I a professional blacksmith. I can't afford to use techniques that waste strength and time.

I'm also good at stepping back from what I think and looking at another person's view, I cherish views I don't agree with and fess to being wrong. Someone who shows me my mistakes is doing me a good turn. If you can show me how a glancing blow is more effective than a solid directional blow I'll give it enough of a try to learn it and say so publicly. I'm all about: Better, Faster, Easier, Cheaper. Show me.

Frosty The Lucky.

[jlpservicesinc]

I apologize..  for the complete disagree statement. Being dyslexic I have to remember to point to the part I disagree with and to include it..  In my mind I was referencing  this particular item as it's just PSI.. 

  I have a very hard time when someone puts a limit or simply spouts equations or the like as finite or absolute.. Or on the books..    Sure in a perfect world with no variables or "the human condition".. 

You are correct that it is simply " Pressure" applied pressure with no reference to the subtle variances as to how its applied..  This is what i was disagreeing with in regards to hand forging..

What you say Carries weight..  So, to simply say it's PSI leaves out a lot of information..  And can lead someone to believe it has nothing to do with how the hammer is used..  and this can in reference also mean that with a Face or peen makes all the difference..    As it can.. or can not...   

In close dies  " Pressure" is what moves the metal to extrude into the cavities..   Hydraulics..   Using swages or dies at the forge.. etc. etc..  In it's simplest form.. It's all PSI.. 

I could never show you a picture of this " smearing" as No one would believe it and without scientific equipment and a slow motion camera unless you are there to feel it it will mean nothing..  And easy to disclaim " without proof" The examples or pictures above say it all..  nearly all the metal was pulled in the opposite direction...  This was all done with the peen of the hammers with no correction blows.. You can see that the metal is some places were torn as I pulled it apart.. 

As you know metal moves  in the direction of the least resistance... This being the case using the face or  peen of a hammer if the hits were straight and true would give the same amount of metal moved one each side of the center line of the bar if the thickness is the same, the amount of metal moved would be the same..    This is not the case in the pictures above.  

If it sounded like I was attacking you.. It's not the case..  Belief in something, Is all a person has....    So getting a clarification at the bottom of your statement says it all.. 

I get tired of going online and seeing miss information being handed out  hand over hand and being given to the masses who assume the information is correct since they saw it or saw xyz do it on youtube...    Miss information or a lack of information can be one and the same..    I use reference points like power applied in martial arts and such to help with visualization..  The problem with using anything like this.. Is opening the door to more conjecture.. Just like in court...   I'm not a debater.. I just share the information as I see it... 

how do you explain a sunset to someone who has never seen one... ????  Just writing this could if someone wanted to add a whole other conversation to this simple statement.. Which by the way is how it feels when I try to explain these things which to me are very simple.. 

There is no medium I can use to good merit in some cases to explain what happens other than videos and even there is a lack of a full picture as the video only depicts what is being shown in that one example..  there might be 1000's of ways I know how to make or forge something.. But in the video it only shows 1 unless it's like the tapers video where there were 4.. Is 4 the only number I know how to do.. No.. But it's the 4 that were shown..  So then what..     Each video I have done for the most part has nothing to do with the item made.. It's about the skill set used..    

Every time we forge we actually smear the metal..  Smearing as I am referencing it is when as you say pressure is applied and the metal slips away from where it was..  We are always smearing it..  We smear it across the face of the anvil.. It won't smear like clay or mud but its why there are grain boundaries (yes, I know it's not the only reason but the metal is being worked at a differential of internal pressure or PSI) Therefore smearing is taking place maybe microscopically.. but smearing just the same... Same on layered billets and keeping the layers even..  an extra pressure or hit will change the pattern as it is distorted internally as it's smeared..  You can see it..

The internet as  pointed out in another thread is a double edged blade..    Good and bad information..   How does one weed through it if they don't know..    20/20 and hind sight all play in on a persons journey.. 

I am not a word smith,  and I find sharing information that is outside the discussed box to be challenging to share because I end up having to explain it all and it's not the general audience that I end up having to discuss it with..  It's people who have seen, or believe or aren't willing to look at what I show and then formulate whether they want it or not..  

i discarded things that don't work a long time ago...    As to being a professional smith..    I'm not a pro any longer.. Nor do I feel as though the skill set I have now is anywhere near where it was 15 years ago.. So in my mind I know the skill sets as they are mine..  but I'm slow, out of shape and I can't simply look at a piece of metal anymore and know exactly how much I need to make a given item..  This leads to a slower process...  But I don't have a desire to be a pro anymore..     If I did, that is what I would be doing.. 

I'm just trying to help..  The way I do this is by offering extra information that sadly goes against what most are showing today as the only way..    

I end up having to go the extra distance to explain it..   Or do I?     What is the time worth?    Again, I apologize, I am very sorry,  and to clarify..    You are correct.. It's all PSI....   

[JHCC]

39 minutes ago, jlpservicesinc said:

I could never show you a picture of this " smearing" as No one would believe it and without scientific equipment and a slow motion camer

Well, I’m going to give it a shot. Imagine for a moment that the workpiece is made up of many flexible rods standing on end, as in (1) in the drawing below.

If you hit straight down as in (2), those rods will buckle outwards from the center, pushing the material out equally on all sides. 

If you strike an angled blow (hammer face parallel to the workpiece) as in (3), those rods will all get deformed in the same direction. This pushes the material out in the direction of the hammer blow. 

Make sense?

[Frosty]

I wish to apologize to the forum for letting myself respond to an emotional reply to a simple statement. I do not wish to get moderated or worse and will not respond further.  I've been called enough names.

Again, my sincerest apologies to all who have been subjected to the exchange.

Humbly Jerry Frost

[jlpservicesinc]

46 minutes ago, Frosty said:

I wish to apologize to the forum for letting myself respond to an emotional reply to a simple statement. I do not wish to get moderated or worse and will not respond further.  I've been called enough names.

Again, my sincerest apologies to all who have been subjected to the exchange.

Humbly Jerry Frost

Frosty, I value you opinion as I do with every bodies here or anywhere for that matter...   

I find internet conversations to be very challenging for me and with the limited speed with typing or information that can be passed along.

I find it to both be irritating and  frustrating..   Because I think so much faster than I write or speak.. It's like all the words get jumbled up and the only advantage writing words has for me is I can proof read it over and over and over again..  And then it still has errors as to what I am trying to say..   The devil is in the details..  And this is what happened... 

I used to be a very generalized talker as it was very simple and since the person was 1 on 1 it allowed to just show something....  With this medium, I can no longer do this.. I have to be forced into being more articulate and specific with the written words If I want to get the information across in a useful way..    It's just how it is..   

I took no offense at what you said... And as you pointed out..  It was my generalization (though a miss giving) that put the hurt on...   Again I am sorry for that.. 

I love how well written your replies are and usually you end up clarifying the points which I can not express in written form..   

Again, I took no offense at what you wrote and understand how it was miss construed..   My bad,  I am very sorry..  
 

 

 

[JHCC]

Okay, it sounds like we're all back on track. 

Let's get back to the subject at hand. Jennifer, do you think my last set of drawings shows what you were trying to describe about "smearing" the metal?

[jlpservicesinc]

Yes and no..  the 2 picture is correct if in the middle of a bar with = heat and = distance to an edge..  Or no heat.. But simply a rod, or ball or object with an even shape pressed into it..  . 

The hammer face sinks in and the metal has to be displaced. (just like pushing a thumb into clay.. As your finger goes into the clay.. It will create drag marks (smears). 

  Using a round hot punch with flat end to punch a round hole in flat bar shows this as the punch is driven in it will gain thickness around the hole as the material is displaced and put back into the parent bar around the hole..  the bottom of the punched hole against the anvil will now be raised off the anvil face. and most will flatten it back out..   The slug that comes up is usually about 1/16 or less in thickness..  Where did the metal go? It started life as a 1/4" or more..  The thickness of the slug is based on 1/4" hole in 1/4"-5/16" or even 3/8" stock thickness.. 

Last hinges I made I had to account for the length the bars would grow since the holes has to match the exact distance to existing holes..  The hinges grew 1/16" longer for each punched hole..  It also grew a 1/16" all around the hole.. Thus creating a bow in the sides of the hinges where they were punched..   The punch was a 1/4" taper.. 

So the rods in your first drawing are being smeared against each other as they collide with the supporting rod on the side of it and forced to move out of the way..  They smear each other..  

 

Picture 3  you have the same as above with the face flat in picture 2 but are not including an angle to the hammer..

In other words if you were to hit the metal with the flat  of the hammer on a flat anvil  on flat metal there will be very little in terms of a pulling or pushing effect..  The flat face of the hammer simply can not grab the metal..(change in angle to the face) it will slide off the metal with a blow with less force or (PSI) that is less than a straight on blow or strike with the hammer..   

The face of the hammer has to have a feature that will grab the metal.. With the flat face using the  heel or side of the hammer face can be that feature. (keeping in mind which is your strong side vs weak side in a hammer strike).   With both the Swedish and French hammers I have they have convex faces so can be used to good merit.. The French is rounded from side to side. (not as good). The Swedish is rounded Top (front) to heel in only 1 plane or axis.. 

This means it can act like a wide peen when doing directional strikes like when pulling towards myself in the tapers video..   

When working at a bottom die like the horn or fuller or such even the corner of the anvil these act as pressure concentraters..  when you forge a shoulder into a bar you will notice the top portion retained at the anvil lip will have a rounder shape but also longer as if it was pushing of the parent bar not on the face of the anvil..  If you look you will also see where the sides of the bar were pulled up into the flat metal.. There will be small lines running along the forged shoulder as the metal was smushed and pushed forwards away from the parent bar.. 

You will also notice as this shoulder is forged that the metal behind the anvil face attached to the parent bar is wider Though it wasn't forged down..  

Here is another example.. Just be careful doing it as the board will move

If you can take a long handled framing hammer and with a 2X4X 12 or longer ",  on the ground.. Go over and take  a downward swing hitting it a good hit with a face angle of about 5 or 10 degrees...  it will want to move in the direction it was hit though still completely flat on the ground..   There will be a depression in the board from where it was hit but the dirt will show where it was moved to.. 

This was the building blocks I started to look at..     

[JHCC]

5 minutes ago, jlpservicesinc said:

Picture 3  you have the same as above with the face flat in picture 2 but are not including an angle to the hammer..

Well, obviously this is a complicated problem with many variables. What I'm trying to do with these drawings is isolate out the extraneous factors and focus solely on one variable at a time.