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I Forge Iron

Let's talk about magnets


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Can you heat, hammer and shape a magnet without losing it's magnetic qualities?

 

I have this idea for a desktop memo holder, where I would use a small jewlers anvil (Probably mounted on a piece of oak or something) and i'd like to find a nice size block magnet to heat and shape into a peen hammer head that I would drill and fit with a nice handle so the hammer could be lifted off the anvil and notes could be left under it magnetically holding them down.

 

It may be a silly question, but is this possible, or should I try and make a hammer head out of iron and find a bullet magnet or something to glue to the hammer face?
(The second option may not look as good since the magnet seam would show, unless I drill out the hammer face, but that may be more work than needed.)

Thoughts?

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Heating will destroy the molecular alignment in a ferrous magnet.

 

 

It sounds like a clever project, ... so why not just machine the hammer head from a "bar" magnet ?

.

 

 

( i think there IS a process for magnetizing ferrous metal, by passing a current through it as it cools, ... but it seems like a lot of trouble, when other, simple solutions are available. )

 

 

 

.

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SmoothBore, you think I could grind a bar magnet to shape? I didn't think I could get it as smooth as i'd like, but I guess it's worth a try. I'd still need to drill it for a handle.

(I get the feeling tiny shavings are going to get stuck everywhere!) :)

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Or.......

 

Forge your hammer head to shape, but don't forge out the face of the hammer.  Leave this a bare cylinder that you can round off and thread.  Then forge a hammer head face (using the same parent stock) that you can drill and tap to mate to the threads on the main body.  Insert a strong magnet into the bottom of the face piece and screw it all together.  

 

The seam between the face and body should be lost in the finishing process depending on where it is in the design.  

 

Will the magnet be strong enough to support the weight of the hammer?  Would it make sense to put a larger magnet in the anvil instead?

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if the metal is heated, its reduces the effectivness until it gets near AC3 and then It will stop working as a magnet, since the aligmemnt of the grains will change upon conversion.

 

So I can't help but wonder, if you were to heat the finished piece to 'near AC3' and let it cool inside a strong magnetic field, would it retain the grain alignment and become a magnet?  If so, you wouldn't even need to start with a magnet.

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Thomas, I thought about using a thin magnet (like the ones they give out for business cards to put on the fridge) but they are more rubbery than metalic, and I would lose that satisfying sound of the CLINK when metal hits metal!  :)

Vaugn, that sounds a bit more complicated than I can handle myself (I don't have a tap or dye). I was thinking I could drill out the center of the hammer head and place one of thos strong round magnets inside.

Thanks for all the suggestions, I'll let you know what I come up with.

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Forge the piece, heat to non-magnetic and place in a strong magnetic field. DC electromagnet works better than laying it next to a bar magnet but you can just lay it magnetic north south and do the job. The stronger the field the stronger the effect. Have an old motor around?

 

Frosty The Lucky.

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Jim, it wouldn't need to be threaded - that's just me talking all complicated.  A gob of epoxy would hold the two pieces together, or it could be blind pinned.  The key would be to camouflage joint by making it look like it was supposed to be there.

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Starting with a magnetic round bar, ... I'd turn and polish the head on a lathe, ... then cross drill the handle hole, and elongate it with an end mill.

 

A simple easy little project.

 

Forging is only one of the "tools" at your disposal, ... and it's my opinion that using the "right" tool, ... is always the correct path.

 

 

 

.

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machining magnetic material brings its own challenges. as well as magnetizing tools and chucks, rare earth magnets can catch fire and release some toxins from the dust while machining. need to be a little bit choosey about what gets ground or milled.

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Being magnetic or non magnetic is NOT a function of grain alignment. It is function phase-austentite is non magnetic while ferrite is magnetic. The difference between austenite and ferrite has to do with the relative position of carbon and iron atoms in the crystallographic matrix. Those change with temperature in a plane carbon steel. The 300 series stainless steels are alloyed with nickel which alloys austenite to be stable to cryogenic temperatures which is why those alloys are non-magnetic even at room temperature.

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you are saying that the realignment caused by heating is not effecting the metal from being a magnet ?  I was under the impression that polarity  is what cause it to be a magnet or not. and the scrambling of the grain, or what ever you wish to call the cubic structures, from the heating removes that alignment. 

 

I do admit that magnitism is not my field of speciality, but i also know liquid metal can generate serious magnetism.  but that is getting a bit too far into physics for me or IFI.

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You guys are confusing "grain" with "crystal structure" and "atoms." It is the alignment of the atoms which makes for magnetic or nonmagnetic. It is the crystal structure (how the atoms stack, whethere aligned or not) which makes for ferrite or austenite. It is whole crystal, whether magnetic ferrite or nonmagnetic austenite, which constitues a grain. What we do with or to the grain structure makes a differenence for mechanical properites, of course, but has no influence on magentic vs nonmagnetic.

 

Other than carbides and inclusions, you won't find any "molecules" in steel - only a crystal matrix.

 

I hope that was more help than hinderence.

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