# Making a magnetic clamp/stop



## sshorter (Nov 7, 2009)

I'm interested in making a magnetic featherboard/stop that will work on my steel tool tops. It looks like rare-earth magnets are the way to go but how big should the magnet be to safely remain attached to the table if placed under stress. I see that you can buy some magnets with holes for screws already drilled and it seems like it would be pretty simple to attach a few to some wood blocks and make a bunch of good easy stops. Lee Valley says the 3/4" and 1" diameter ones are super strong. Would they be good enough? Thanks very much for any advice!


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## bobj3 (Jan 17, 2006)

HI

You may want to check out the links below

4 Piece Magnetic Welding Holders
7-1/2" Multipurpose Magnet Holder
Retrieving Magnet, 250 Lb. Pull

The trick is not getting them down it's getting them up, I use 10" and 12" old speaker magnets in the shop, they will suck a hammer out of your back pocket, the trick is getting the hammer off  bolts and nuts, forget it without siding them to the side and pull like hell..


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sshorter said:


> I'm interested in making a magnetic featherboard/stop that will work on my steel tool tops. It looks like rare-earth magnets are the way to go but how big should the magnet be to safely remain attached to the table if placed under stress. I see that you can buy some magnets with holes for screws already drilled and it seems like it would be pretty simple to attach a few to some wood blocks and make a bunch of good easy stops. Lee Valley says the 3/4" and 1" diameter ones are super strong. Would they be good enough? Thanks very much for any advice!


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## jschaben (Jun 21, 2009)

sshorter said:


> I'm interested in making a magnetic featherboard/stop that will work on my steel tool tops. It looks like rare-earth magnets are the way to go but how big should the magnet be to safely remain attached to the table if placed under stress. I see that you can buy some magnets with holes for screws already drilled and it seems like it would be pretty simple to attach a few to some wood blocks and make a bunch of good easy stops. Lee Valley says the 3/4" and 1" diameter ones are super strong. Would they be good enough? Thanks very much for any advice!


Hi Stephanie - Magnets are real handy but you need to remember that while some may need a good deal of force to lift directly off a surface, they will move laterally with much less force. I don't know how large the ones Maglock(sp?) uses but I suspect they are substantial. 
You're right, you can get rare earth magnets in virtually any form you want, including rings and blocks with countersunk holes.
Check out this link. Gives specs for each one and much more data than I have any clue what to do with.
K&J Magnetics - Strong Neodymium Magnets, Rare Earth Magnets


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