# magnets



## SE18 (Jun 5, 2013)

For oxyacy welding, I use clamps but wondered if magnets can also be used as work-holding devices, specifically rare-earth magnets like some shown here: http://www.magnet4less.com

Would the heating up of the part cause the magnet to lose its magnetism? Obviously I'd not direct the flame at the magnet.

Since I have to place an order for some mini magnets for a science project, I thought I'd include larger magnets with my order if they're useful.

Thanks

Dave


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## 8ntsane (Jun 5, 2013)

There are many work holding magnets for welding that don't seem to mind the heat. The little mini magnets do seem to loose the grip when heated. when I used to do a lot of welding I liked using the mini magnets because of their size they didn't get in the way. But it seemed the life span was short lived.

I don't know the differences in magnet construction,, but those mini magnets, the high powered ones, don't like heat.


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## Ray C (Jun 5, 2013)

I use magnets all the time but only long enough to setup the part and do a few tack welds then, I remove the magnets as the tack weld is much stronger.  I should think magnets would be fine with gas welding.  They cause problems with both arc and TIG as the molten puddle wiggles around and with TIG, the plasma dances all over the place.

These are the ones I use:


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## DMS (Jun 5, 2013)

Neodymium magnets can't take the heat! Most of the magnets used for welding setup are ferrite magnets. good thing is they are much cheaper than Neo, though not as strong.

I personally have not had much luck with using magnets. I have better luck lining things up, tacking, then making final adjustments. If I need things to be held rigid, I really like the Bessey "F" clamps.


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## Rbeckett (Jun 5, 2013)

I use a couple of the square type of magnets for jigging up work.  I use them carefully because they will cause arc wander if you attempt to weld to close to them.  But for common welds what need to be relatively square they work pretty darn good.  I have three different sizes of them and that allows me to work easily with them and they are easy to remove when I am done.  HF and most of the common tool outlets like TSC have them available for pretty reasonable.  Don't spend a lot on them because they are not going to last a long time and are easy to damage if they keep getting dropped or knocked off of things to the floor.

Bob


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## Ian Bee (Jun 5, 2013)

In my opinion, there is only one type of magnet to use...

The NOGA switchable magnets.  I have eighteen of these on a shelf, each with an 8.0mm. x 60 mm. shoulder bolt attached to the tops for easy gripping.

They are very square, and the 50 mm. x 60 mm. units are extremely powerful.

Reason?  You don't have to wrestle the damn things off the job, and no stuff sticks to them.

Yes, as in previous posts, you get arc blow if too close, unless, you are sandwiching aluminium between them, doesn't seem to play as much havoc with the Tig.

Because of the M8 threads in the top (although shallow...), you can bolt all manner of flat steel bars to them, as well as making your own protracting angle devices.

The Noga magnets normally only stick on two of their faces, bottom & back, but there is still plenty of force on the sides.

One thing to bear in mind...

If the magnet is holding on two of its faces, the force is slightly WEAKER, than if it was simply stuck down on a steel bench, or a machine, holding a dial indicator. 

Only way to go in my opinion!


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## SE18 (Jun 5, 2013)

thanks for ideas. I've seen lots of the ones Ray pictured and was aware of that. Some of the rare earth hold upwards 65lb but I'll save the rare earth for other projects then and stick to the HF kind. HF can't screw up those magnets, I'm sure. I was btw, aware that dropping or throttling them with a sledge makes them lose their properties in a heartbeat

thx


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## SE18 (Jun 7, 2013)

http://www.magnet4less.com/product_info.php?cPath=1_5&products_id=44

This neo mag block might prove useful in jigging up work that needs to be exactly 90 degrees (like in welding up an angle plate using oxyacy gas--otherwise arc wander).

The problem might be pulling it off, says 220lb.

Also, I suppose accuracy depends on exactly how square these squares really are.

Any comments on how to pull them apart. 100 lbs seems easy but there's nothing on it to grip with 200+ force


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## Rbeckett (Jun 7, 2013)

Breaking the magnetic bond is actually very easy on these angle blocks.  All you have to do is lay the block on it's side and it becomes much less powerfull and you can easily remove it then.  When it is employed in a true N/S orientation it is very strong, but altering that just slightly reduces the strength dramatically, making removal and repositioning much easier.  Hope this helps guys.  This is another great discussion that I am glad I have had the opportunity to discuss and add my .02 to.  Thanks a ton!!!!

Bob


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## SE18 (Jun 7, 2013)

thanks, Bob, If I can't break them apart, I'll blame you


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