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I Forge Iron

How to draw out thin but wide steel without folding


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Couple of things: when you get an overlap like that (which we call a "cold shut"), it is a Very Bad Thing: it can lead to the whole piece cracking, if you're not careful. Cold shuts happen for a bunch of reasons, but in this case it looks like (A) your piece wasn't hot enough and (B) you weren't hitting hard enough. 

Think of your workpiece as a narrow upright rectangle of modeling clay. If you tap-tap-tap at it, the force of the blow will only be felt at the top edge where your hammer hits it and at the bottom edge where it rests on the anvil. Those edges will mushroom over, giving you the effect you see in the picture. Now, imagine that you give it a good, solid blow. The force of the blow penetrates all the way to the center of the rectangle, the edges move closer together, and the sides bulge out in the middle. See the difference?

The second thing that you need to keep in mind is that even if you do get some mushrooming on the edges, you can still salvage the piece by correcting it immediately. What you want to do here is to alternate your blows on the edges with blows on the sides, to keep the mushrooming under control and to forge any bulging at the edge back into the center of the piece. Again, think of the metal as clay and of the hammer blows as pushing it in the direction you want it to flow.

In the words of the late Alexander Weygers, "Little corrections, little corrections. With the little corrections, we avoid the big corrections."

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Why were you hitting it on edge? Throwing knives aren't "knife" steel, the last thing you want is one snapping the tip off and flying off in an uncontrolled direction. As young teens a friend and I must've made a couple hundred throwing knives. We made 6 each to start then friends wanted their own so we were selling them for $5.00 ea. and made a killing. 

Mild steel was too soft but an old misery whip (two man cross cut saw for the uninitiated) was perfect. We normalized it over a BBQ briquette fire and cut with a saber saw and did a little grinding. They were springy enough we didn't need to do any heat treatment.

The ONLY time we hit one with a hammer is if we bent the tip. 

If you really want to forge throwing knives don't forge them so thin. It's not a big mistake or mystery, think of this as a step on the learning curve. 

Frosty The Lucky.

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I don't see this addressed so: when you are hitting on the side to make thin stock thicker it's UPSETTING not drawing out.

Upsetting tends to be a 2 steps forward, 1 step back process: you hammer on the edge and then you clean it up on the flat, repeat ad infinitum...

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