Striking hard on hard

[lyuv]

It is "known" (...) that you must never hit two hardened hammers together, for they might shatter violently.

BUT - anvils are hardened, and we do hit them with hammers. At least I do, when I miss a blow.

So ? Is that only a myth, or are we playing with bombs?

[Foundryman]

I've chipped a hammer face with a missed blow and I can't count the number of anvils with chipped edges I've seen posted here so there's definitely a risk.

There's a reason why smiths traditionally wear heavy leather aprons! Eye protection is less traditional but just as necessary if not more so.

[arftist]

Use a soft hammer until you learn hammer control.

Seriously.

[ThomasPowers]

Also anvils generally are not hardened as hard as many tools are.  Hardening is not a binary process but rather a sliding scale---just like water can be "hot"; but all hot water is not boiling hot.

Some brands/sizes of anvils have harder faces than others and so are known to chip more in use. (The ball bearing test does a good job of showing the range of hardness's of anvils)

[Steve Sells]

one does not intentionally hit the anvil with the hammer, we hit our work. IF your aim is that bad, perhaps smithing is not for you

[ThomasPowers]

Hammer control is a learned skill and seemingly one of the hardest for students with *no* hammer experience these days.    I have learned that a lot of my first class time will be demonstrating to students what they are doing vs what they should be doing. (Quite a few tend to strike behind where they should)

[arftist]

It is very easy  to anneal a hammer head.

Accurate hammer blows are integral to forging...if you are striking the anvil you just need a lot more practice. 

[ThomasPowers]

Preferably NOT on my anvil!

[Joel OF]

I think Thomas' points about brand variation & the sliding scale hits the nail on the head in technical terms.

In practice missed blows are inevitable, especially when holding something awkward & working on your own. I'd "prefer" to have a missed blow hit the anvil face than the corner, so if you are forging something tricky and it needs to be forged on a corner, you could always make a mild steel hardy block to forge it on. That way with a missed bloe you'd either just dull the block's corner, or miss and hit the anvil face.

In practical terms it's a sliding scale too. I'd prefer to have a missed blow with a 1.5lb hammer working on the anvil face than a missed blow with 7lb sledge working on the corner.

[eseemann]

I have seen several blacksmiths on Youtube and some people that may be called "Youtube Blacksmiths" that have treadle hammers that are basically 2 good size sledge hammers bolted to  a frame. I am willing to guess that as long as you have some material between the 2 hammers there would be less of a problem since in that case you are not striking hard on hard. I wonder if the act of using a sledge hammer head as a anvil will cause the hammer head to soften once put in to use. I am thinking about the "what ever works" blacksmiths that used (for example) a good size sledge hammer head in a stump. A hammer head at 8# to 10# will need much less heat transfer to become softer than a 100# anvil. 

On a side note I have massive amounts of respect for by taking what they have and still do great work. 

 

[arftist]

It would take intentional negligence to soften an anvil (or a large hammer head. Simply too much mass.

[eseemann]

It was what you might call an uninformed guess. 

[Frosty]

People exaggerate warnings and hazards just like we tend to overbuild, it's a safety margin thing.  Hammer heads struck together do NOT shatter, that's an exaggeration. Have you seen the MythBusters episode where they went to some pretty extreme measures to unsuccessfully get a hammer to shatter? They will chip the edges though but a mere human is really unlikely to be able to get one to break with centered blows.

Using sledge heads for anvils and treadle hammer heads and anvils isn't very risky and you can leave them as is, sledges aren't usually left very hard, they get used to hit all kinds of unpredictable . . .  stuff really hard so they're made tough rather than hard. A missed blow with a single jack on the Soderfors usually leaves a flat spot on the hammer face.

Same for anvils, my Soderfors will just make a new file skate on it's face, chipping is always a risk. When I'm shouldering a piece the chances of a missed blow striking an edge is at it's highest. Yes? There are a few tricks I show students and heck anybody using MY anvils: #1 keep your eye on the target! #2, Both elbows indexed against your side. This helps prevent chasing the work all over the anvil with the hammer done by new folks. #3 A big fat wide faced hammer. There are a couple reasons for this, first it's harder to miss if the hammer is wide, try swatting a fly with a radio antenna is you don't believe me.  The wider face distributes the blow over a wider area on the anvil's face or edge so psi and shock loading are much lower even though the total energy is greater. Big and heavy draws a shoulder in far fewer blows reducing the chances of missing one proportionally.  Lastly students are afraid of BIG hammers so they're more cautious and less likely to miss. 

I've adopted an new technique to get students to remember NOT to part stock on my hardies! I make them sharpen them with a file and sand the marks out of the hammer face with fine emery cloth. To MY satisfaction of course, it works marvelously to improve a student's attention to control when it takes them an hour of hand sanding to correct the consequences. Sharpening the hardy only takes a few strokes usually but polishing up a hammer face takes time and both are useful skills. 

Frosty The Lucky.

[ThomasPowers]

E you may want to look up "work hardening"  with use things tend to get harder not softer---unless you get them up above the dislocation climb temp to remove work hardening or above their original drawing temperature---which is very unlikely as it would probably be above the ignition point of paper...

[eseemann]

Thomas, 

I get work hardening but it had slipped my mind. The hammer I was thinking about becoming softer was in the case of a sledge hammer head being used as an anvil. I do see what you mean in that the striking surface would have to be at or above Fahrenheit 451 (thank you Ray Bradbury for that factoid) for an extend amount of time. As a matter of fact I learned something from  the tinsmith at Williamsburg and that is the tin and the iron that made up the tin clad iron the colonial tinsmiths used would work would both work harden. The problem what that you could not heat the iron up to soften it w/o melting off all of the tin. You had a given number of hammer strikes and that was that! 

[Desmond Redmon]

Over the years many anvils suffer chipped edges, I have seen a few with broken horns.  Typically though what I see is surface damage from hitting cold metal on the anvil (including hammers) but other than chips along edges or someone really overdoing it on the top of the horn I don't shattering tools as a serious problem with cast steel or forged anvils.  On cast iron anvils (cheap and found in many hardware stores) might be a different story but I have not played with one to know yet. 

  Theoretically if someone had really overheated the hammer head, and quenched it, it could have enough built up stress, cracks, and poor structure that it could be super brittle I think?  Potentially anyhow but that would be a one time learning curve I would think.

   P.S. If you are still hitting your anvil with the hammer, what worked for me was starting with my smallest hammer making nails (I wasn't really looking for any given size just practicing tapers and hammer control) I made them with a 10oz tacking hammer, then moved up to a 1lb ball pein,  and so, not changing sizes until I made 100 nails without hitting my practice anvil (a chunk of mild steel 2x4x6 I found in the scrap yard).  I had already spent a weekend taking someone else's dings out of my anvil and after adding a couple decided I didn't really want to spend an hour removing the ridges I generated every few days. It was a seriously boring and kind of grueling process but an effective method of giving me at least rudimentary hammer control.

[marcusb]

I have found modern hammers to be tempered much softer than old hammers. My guess is liability concerns on quality hammers and low quality steel use to manufacture imported hammers. 

 

[eseemann]

I remember a claw hammer from discount department store that had a hollow space under the head and one day a nail punched through the head of the hammer.

[ThomasPowers]

One thing to remember is that they had cheap tools way back when too---they just didn't survive to make it to us---a preservation bias.  The good ones *lasted* and were maintained and cherished! (The 1897 Sears Roebuck catalog offered tools at several quality levels for instance)