Tip: Clamping Parts In Difficult Situations

[David Paule]

Want to clamp some parts that haven't been drilled yet and are too far from an edge for a regular clamp?

I bought some Neodymium magnets, grade 42, from www.kjmagnetics.com. These are 1/2" in diameter and 1/16" thick. I chose the ones with the field axially-oriented. They are VERY strong. They'll hold aluminum parts through a thickness of about .155", although that's pretty much the limit to being useful. With typical sheet thicknesses, they hold quite well.

They're shiny and smooth but can still scratch aluminum.

Put one on one side of the joint and one on the other.

Some caveats -

These magnets are brittle and fragile. They're easy to crack, and the pieces, which might be small, are still very magnetic. Thicker might be a bit more durable.

They are strong enough to wander around your work area in search of some iron. If you have other magnets nearby, they'll find each other.

They are difficult to separate, one from another. In the stack, it's easy to slide on off, but two together are much more difficult. I use a box cutter knife to separate them.

These can cause a lot of damage. Be careful with them - especially if you're using electronic equipment out in the shop, e.g., hard drives. And if one falls on a skin and there's a steel part on the other side, you could put a nasty gouge in the skin.

Dave