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why taper square?

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The dendrites are composed of atoms in a cubic lattice. Reference the book cited in post above.


yes right its a cube thats square

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Posted · Report post

...because the round cubes are just plain funny-lookin'

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Posted · Report post

Dendrites form during solidification and they are NOT square. A dendrite grows from a nucleation site and develops primary, secondary and tertiary arms. If you look at it with the aid of an SEM you will see that It actually looks a little bit like a fern or evergreen, which is where the word dendrite comes from. While it is true that the iron crystal lattice is cubic, that is on the atomic level. At larger scales, the arrangements are not cubic unless forced that way by deformation. As I noted in my earlier post, we forge square because that is the most efficient method and that has to do with constrained and unconstrained surfaces, not atomic structures. At the macro scale, iron has no particular tendancey to form cubes. It takes on the shape of the contain in which it solidifies and after that it takes on whatever shape it is forced into, whether square, round or some intricate configuration. That ability to be formed in some many ways into so many things is one of the reasons iron based alloys are so widely used.

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Sub atomics aside, as has been alluded to before, but perhaps not stated directly, is that by forging square you're forging though the center line of the stock. any force applied to the stock not through the center line, when drawing down has a shearing effect ( the piping Mr.Newman referred to)  and will tear your metal apart eventually. This is also why drawing down hex works.It's all about the center line. You could draw down a 16 sided object if you had perfect registration and worked evenly, but that would take much longer to do well than the usual, square, octagon, round. Take care, Matt

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Sub atomics aside, as has been alluded to before, but perhaps not stated directly, is that by forging square you're forging though the center line of the stock. any force applied to the stock not through the center line, when drawing down has a shearing effect ( the piping Mr.Newman referred to)  and will tear your metal apart eventually. This is also why drawing down hex works.It's all about the center line. You could draw down a 16 sided object if you had perfect registration and worked evenly, but that would take much longer to do well than the usual, square, octagon, round. Take care, Matt

Wow! someone finally said it :-)

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Posted · Report post

Here I thought we did square cause most of us can count that high!  (and on the fingers of one hand even if a couple of them are a bit odd looking.)

 

May I mention that Patrick is not only a metallurgist in industry he works for a FORGING company to boot!

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Posted · Report post

So that's my problem, I get lost around 3...

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So if I were to pick and chose the bits that I like from all the previous posts, I come up with this

 

1. drawing down square gives me a easy and predictable reference (gauge) for the amount of taper I am achieving as I work.

2. I am moving the mass mostly in only one direction perpendicular to the hammer (as opposed to spreading it like a pancake) avoiding the shearing effect.

3. the square shape lets me deform the whole profile of the metal not just smear the top and leave the centre relatively untouched.

4. the total number of hammer blows is reduced as the fuller then flatten technique of drawing keeps the square shape without (too many) extra correction hammer blows.

 

Is that a fair summary or have I missed the mark completely?

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Posted · Report post

I think you got it.

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Another reason to love IFI--this thread sent me to school and I didn't have to pay tuition...

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