The Anvil; understanding your tool

[SinePari]

I'm going to make this a hub of collective knowledge when it comes to The Anvil...


Feel free to add to this thread as you see fit; additional information sources, discussion, conflicting information with supporting reason, questions, etc... All things "Anvil" are welcome.

 

[SinePari]

Here is a video that provides a smith with the reasonings and understanding behind radiused edges of an anvil... Sharp edges don't translate into well finished forgings. In no way shape or form is Joe telling you what you should do, only why it is done and how to do it.

[video=youtube_share;vdv5lrnELTc]http://youtu.be/vdv5lrnELTc[/video]

Joe is a very talented Blacksmith and a wealth of knowledge. If you're curious about forging I recommend you watch subscribe to his youtube channel.

Here is Jock Dempsey's resource page for dressing the anvil, providing even more detailed information and other suggested ways to dress an anvil...


http://www.anvilfire.com/21centbs/anvils/making/anvil_radius.php

 

[SinePari]

Taken from a previous thread;


Reasons why... That's a wrought iron mass with a tool steel top plate forge welded on top. The plates thickness varies in thickness depending on it's overall size, but usually never exceeds 1"... Fishers are an exception because they adhered a double-thick tool steel plate in their castings... Any steel you remove from the face of that anvil, it's gone, and you wont get it back unless you weld on it...


If your anvil isn't a peter wright, it's a german trenton... This anvil is also a german trenton/ boker trenton (yes same as the blade manufacturer)... I presume someone milled the top on this one, because they also milled the side...

Top plate was 5mm thick when I got it...

You can see the milling on the side, which tells me someone with a milling machine owned it at one time...

This is what happens when you have so little top plate on the anvil...

This anvil was ruined. I brought it back to service via specialized build-up filler/ hard-facing rod and donated it to a non-profit nature center that put on demos/classes for kids...


If you mill anvil it can lose its hardness due to the nature of the material underneath the top plate being softer... While the tool steel might still keep it's temper, it will deform...Wrought is very soft in comparison to tool steel. That's why over time, heavily worked areas of the anvil will dip... Sometimes this is called "broken back" or "sway-back"... This even happens with anvils that keep much of their top plate, the soft wrought just deforms over time...

A few hours of forging will clean up the face more than you'd ever expect, if your not patient enough for that use a knotted wire brush on an angle grinder. I have never had any issue dressing an anvil with a light flap-wheel disk either...


If you desire a forging surface that is perfectly parallel to the ground;

Mill the bottom of the anvil's base.... This will remove mass, but will not ruin the forging surface...

 

[SinePari]

The proper means of repairing an anvil is a delicate process with tons of misinformation circulating via the internet. There is no such thing as easily repairing an anvil face!

Welding on an anvil face with XXX18 electrodes, by itself, will provide you UNSATISFACTORY results!

One tried, true, and tested method with hundreds, if not thousands, examples of successful anvil repair is the Robb Gunther repair method...

He did a great bit of thorough research and involved a number of metallurgist and engineers in the hunt for a proper means of repair. I respect this method over all others because Mr. Gunther approached this problem in a calculative manner, used a plethora of expert resources, and found a means of depositing two kinds of filler rod, that when combined, mimic the properties and qualities of the W1 utilized in the original anvil face, without the need of re-quenching the anvil's face.

Robb Gunther Repair Method -> http://www.anvilmag.com/smith/anvilres.htm


Another means of repair that has gained satisfactory results is the utilization of the Messer MG 710, whether it be stick electrodes or tig filler.

Shady Grove Blacksmith Shop- The domestic distributors of Refflinghaus Anvils;

MG 710 -> http://www.blksmth.com/Anvi_base_preparation.htm

I have tried other means of repair in an effort to find other viable methods, but do not have the proven results of the above methods....

Other False Repair methods:

15CRMN; It, by itself, is NOT a means of successful repair.

Stainless Steel (aka "missile rod") welding filler; I would only utilized this for very very small repairs such as pitting...

 

[PaMtnBkr]

Great thread idea SinePari!
I was permanently loaned an older anvil w/out any makers marks that weighs Appx 240 Lbs. It has excellent rebound but the top is a bit dished? Maybe less than 1/8 inch? I would have to measure it. Is this OK for forging? I only do stock removal right now but plan on doing forging this winter. Seems like it will be hard to get a nice flat blade if it's dished out a bit? Thanks for the thread! DonO

 

[PaMtnBkr]

Double Post-Sorry

 

[SinePari]

Great thread idea SinePari!
I was permanently loaned an older anvil w/out any makers marks that weighs Appx 240 Lbs. It has excellent rebound but the top is a bit dished? Maybe less than 1/8 inch? I would have to measure it. Is this OK for forging? I only do stock removal right now but plan on doing forging this winter. Seems like it will be hard to get a nice flat blade if it's dished out a bit? Thanks for the thread! DonO

Even an anvil with a dished face, swayed back, broken-back etc will serve you well when it comes to forging. This form of damage is exclusive to wrought iron anvils and built up wrought anvils with a tool steel plate forge welded to the face... Wrought Iron, or at least high-quality wrought is nearly void of carbon, fibrous, and very malleable in comparison to tool steel. It's pretty neat stuff to look at on an anvil and sometimes, when well finished, presents itself like wood grain. When an anvil is heavily worked all that energy directed in one area starts to sway or dish due to the malleable wrought underneath.

Another feature that comes with an anvil that doesn't have a perfectly flat forging surface is straightening a forged blade or having the means of ever-so-slightly correcting warped blades post quench... It's a PITA straightening hot steel on a dead flat surface...

Post pics of that beast, might be able to give you more info on it...

 

[Stacy E. Apelt - Bladesmith]

Lets talk about physics...anvil physics in this case.

Newton wasn't a blacksmith, but he understood that the mass of an object affects its inertia. He even made a law about it - An object in motion tends to stay in motion and an object at rest tends to stay at rest.

When forging you are dealing with three things
1) The hammer...which is an object in motion. The heavier the hammer, the more inertia it has.
2) The anvil.....which is the body at rest. The greater the mass, the more it resists movement.
3) The work....in this case the bar of steel. It is the thing that absorbs the energy from the hammer when laid on the immovable object.

The ratio of the work to the anvil size should be 1:50 or higher. That means a 1 pound bar of steel requires a minimum 50 pound anvil.
The ratio of hammer to anvil should be 1:20 or higher. That means a 3 pound hammer should have a 60 pound anvil as a minimum.
The ratio of hammer to work is hard to give as an absolute, but the larger the work, and the more metal that needs to be moved, the larger the hammer.

In practicality, a 75-100 pound anvil will do any knife forging. From there it is a diminishing gain..... and above 150 pounds, mostly anvil envy. ( Mine is bigger than yours)
Because the arm will wear out quickly is overused, use a hammer just big enough to do the work. A 2-3# hammer is plenty big enough for most all knife forging.

When swinging the hammer, it forms an arc path to the anvil. When the arc stops at the anvil, the closer to 90 degrees in angle between the humerus and radius/ulna, the more of the hammers energy gets delivered. The longer the arc of the swing, the more energy that gets delivered. The more surface-to-surface flushness between the hammer and the work on contact, the better the energy transfer. Any angle will not only make an ugly divot, it will not distribute the energy completely into the work.

When forging, the anvil surface should be at a height such that the hammer face will sit flat to its surface without twisting your wrist. Put your elbow against your side, stick the hammer straight out comfortably so it is parallel to the ground, and have someone measure from the hammer face to the ground...that is the anvil face height. You can deduct 1/4"-1/2" to allow for the work thickness if you really want to be exact.

When forging, bring in your elbow so it hangs comfortably along side your body. Place your feet evenly spaced apart directly under your shoulders. The toes should form a line parallel to the anvil. Your arm extended and relaxed should place the hammer on the work. Move in and out until it is a comfortable stance and the hammer face is sitting on the work. Raise your hammer with your arm, not your wrist. Raise it 70-80 degrees. Let it come down with the power of your arm and shoulder, not your wrist. Don't push the hammer, swing it. When it strikes the work, the elbow should be at about 90 degrees, with the hammer forming an extension of the forearm. Don't look at the hammer, stare right at the spot you want to hit. After a few hours of forging, your brain will learn to control the muscles in your arm to make the hammer hit where you are looking. If you use the same stance and stroke every time, eventually you will develop forging skills like Sam Slavati ( OK, maybe not like Sammi, but good skills).
When the hammer hits the work, let the "bounce" help bring it back up. If you aren't going to immediately make a second blow ( as when taking a quick look at the amount of metal just moved), let it come up a bit and gently bounce on the anvil face near the hardie hole. The rebound there will help bring it up for the next blow.

It is also very important for the steel to be hot enough. Most steels forge starting when they are 2100F and you should quit at 1600F.

 

[PaMtnBkr]

SinePari, I'll have my daughter take a picture of my anvil. I'd love to know more about it if possible? In the step down from the working surface to the horn, it is dug out really deep from years of repeated ?? I wish I knew what was done on it?
Stacy, "When the hammer hits the work, let the "bounce" help bring it back up. If you aren't going to immediately make a second blow ( as when taking a quick look at the amount of metal just moved), let it come up a bit and gently bounce on the anvil face near the hardie hole. The rebound there will help bring it up for the next blow." I always wondered why smiths did that little bounce on the face like that? Now I know! Thanks! DonO

 

[SinePari]

If it's an english patter anvil, that area is known as the table or sometimes called a shelf, the transition from face to the shelf is called the step...That area is where smiths did their hot cut with chisels, which kept the marring of chisel cuts off the anvil face, furthermore of the finished work...

 

[jacobs]

Right now i just finished my first homemade mini forge out of a paint can and some plaster of paris/sand. the torch is heating up the metal and i was wondering if anyone knew how long it takes to heat up the metal before its ready for hammering?

 

[elementfe]

Good stuff.
One more thing on the physics: Peter Ross told me that I should think of the hammer and anvil as working the steel from the top and bottom side simultaneously.
If you look at your forgings before and after a good series of blows, you'll see what I mean.
Does it matter? I think it does, especially when forging a symmetrical object like a beveled blade.
Yes, you still have to forge on both sides, because you're using two differently shaped "hammers"- one flat and one domed.
I disagree about a flat surface being less than ideal for straightening- my main anvil is a very flat old Trenton 265, and I find it perfect for straightening blades. Proper technique helps.....

 

[SinePari]

Good stuff.
One more thing on the physics: Peter Ross told me that I should think of the hammer and anvil as working the steel from the top and bottom side simultaneously.
If you look at your forgings before and after a good series of blows, you'll see what I mean.
Does it matter? I think it does, especially when forging a symmetrical object like a beveled blade.
Yes, you still have to forge on both sides, because you're using two differently shaped "hammers"- one flat and one domed.
I disagree about a flat surface being less than ideal for straightening- my main anvil is a very flat old Trenton 265, and I find it perfect for straightening blades. Proper technique helps.....

One theory that I like to regurgitate when it comes to the symbiotic relationship between hammer and anvil is Mark Aspery's "Cow Poop" theory... It's probably one of the better analogies on how hot metal moves under the hammer....