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Stock splitting on necking/drawing down thin

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I'm making some door/drawer pull handles.


I'm using 10mm square stock.


Using the rounded edge on my anvil i neck in 10mm from the end of the bar and go quite thin (~3-4mm) then draw the taper back.

this leaves me a lump i can squish for the screw hole.


As i'm finishing up the taper i'm finding the transition at the neck to be splitting.

What's causing this, what can i do to stop it?


I tried doing the second pair hotter which i think may have helped, do i need to go hotter still?


Many Thanks

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I am not sure what steel you are using, but drastic transitions can cause stress in the metal.  Rather than reducing the cross section all at once, try a smaller reduction allowing the steel to reheat before taking it down the remaining thickness. If its stress this should reduce that a bit.

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By splitting do you mean a length wise split or a crack that is perpendicular to your cross section?


If in fact it is the latter it's probably do to taking too many heats to accomplish your tapering. Get the metal hot and hit it faster and harder. :)

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 try a supplier that stocks British steel & see if you get better luck?

  I like Rob Halford too , but how will that help the cracking?  I didnt think about making sure you are at correct temperatures. Good points guys.


P.S.   I could not resist the JP joke... :blink:

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Heat or a too sharp a shoulder top my list of probable causes. Off the top of my dented head that is. Inconsistent steel is next down the list, after a couple few tries you ought to be able to figure out the working temp for whatever you have at hand, or that it just isn't forgeable. Learning the feel of steel is an acquired skill as is failure analysis so you can tell what's going wrong or right. Therre is a lot of forged steel that isn't forgeable at our level, say rampable, controlled atmosphere furnaces, REALLY hard hitting power hammer, press or forge roll, etc. some metals are just too specialized for the home shop.


Failure analysis; I've been trying to figure out what went wrong with that one all my life, just part of the game. <wink>


Frosty The Lucky.

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I think have done what you are talking about myself.   Often looks like numerous cracks going perpendicular to the length at the narrow transition.    My belief it is caused by.


  1. Letting this area get to cold while working other areas near by.  This area gets yanked around a bit if your hammer blows are not perfect and true between both hammer and anvil.  Even then it is going to get pulled, vibrated and tugged and stressed causing cracks in the direction you are seeing.
  2. Working this area to cold.  
  3. Letting this area hang off the far edge while cold but working behind it on the anvil.   This thin area hangs off the far edge and vibrates or whips about causing cracks.
  4. Too many heats maybe but I think that is a symptom of one of the above.    You should be able to get where you need to go with a couple heats on this one.   Others would probably do it in one I am sure. :)  Depending on how detailed and elaborate. Rather than work this down to it's finished cross section you could just begin this area, established the thinner area and section it out then come back to it.   Heat will be against you since this area will cool fast.

I think the solution is as above.    Fewest heats possible without working cold, fewest heats reduces the number of hammer blows and therefore stress cycles.    Don't let this area get cold.    Work thin transitions last or late if at all possible.   Don't let the thin area whip or vibrate while working other areas.    


Changing type of steel might have some impact but I think the above is most important.  


Did you cracks look anything like this?

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One other thought.   Even if you don't see a crack or don't have a complete failure you have to believe that cracks are forming under above conditions.   So avoid the above in order to preserve the long term integrity of your project. 


My two cents based on info from this site and my interpretation of past personal failures (Also called learning!).   I am fine with failure as long as there is learning!

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George Dixon did a seminar a loooong time ago that I attended. He was splitting branching elements out of a flat bar and working them into leaves, etc.


One of the things he said that stuck with me is that you have to get a forging heat on the entire element down into the parent stock to keep the neck from breaking off.


Steel can be more brittle at a black heat than at room temperature.

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