Stop flat bar cupping?

J

Jameasun

Member
Hello all, I am sure that this is a pretty basic question,but I am struggling with it.

I have noticed that I am having a problem keeping flat bar from cupping when being forged on its edge. Do you have any suggestions on how I can eliminate this. Of course the thinner the material and wider it is the more difficult it is. Is there a trick to doing this?
 
Generally once you go thinner then 1/4", "cupping" becomes a major issue. The key is "slow and easy" when it comes to forging. My recommendation to folks is for forging, anything less then 1/4" is a pain! :)
 
Jameasun said:
Hello all, I am sure that this is a pretty basic question,but I am struggling with it.

I have noticed that I am having a problem keeping flat bar from cupping when being forged on its edge. Do you have any suggestions on how I can eliminate this. Of course the thinner the material and wider it is the more difficult it is. Is there a trick to doing this?
Click to expand...

Not a problem, just need to work it more evenly, on edge on flat, gradually forming your tip/taper or whatever you are forging in. I dont find it a problem until 3/32" really.
 
When profiling a blade by forging, every time you hit the steel on edge it will 'mushroom'. If you don't work the sides of the billet this can become a problem. So, work the sides of the bar. Two strikes on the edge, then 2 strikes on the flat to fix the 'mushrooming' as it happens, it is just part of the workflow required to forge a blade to shape, and becomes second nature after a while. 3" wide 1/4" thick stock can be just as much a problem as 1 1/2"x 1/8", one of the keys, IMO, is to work the steel while it is hot, as simple as that sounds... hotter steel allows the force of the hammer blows to go deeper into the steel, so to speak.
 
Keep ahead of the problem too. If you allow the bar to cup or gutter on you too much you run the risk of folding the steel over itself and forming a cold shut that you will forge down into the bar ruining the blade so George's idea is two blows on the edge and two blows on the flats may be a good idea.

Doug
 
Keep ahead of the problem too. If you allow the bar to cup or gutter on you too much you run the risk of folding the steel over itself and forming a cold shut that you will forge down into the bar ruining the blade so George's idea is two blows on the edge and two blows on the flats may be a good idea.

Doug
 
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