Uses for Magnets

**rgsparber** · Dec 31, 2018, 08:17 AM

Magnets are useful both in and outside of my shop. Here are two examples. Hopefully, others will trot out their applications for all to see.

If you are interested, please see

https://rick.sparber.org/magnets.pdf

Your comments are welcome. All of us are smarter than any one of us.

Thanks,

Rick

**mklotz** · Dec 31, 2018, 09:27 AM

Some more uses...

At Michael's craft store you can buy a card of six neodymium magnets that are exactly 1/4" diameter. This means that flat-bottomed depressions to receive these magnets can be drilled in material using nothing more than a 1/4" endmill. I made aluminum soft jaws for several of my vises and used this trick to mount magnets on the reverse side so they would stick to the vise jaws.

I have several of those articulated lights with the built-in circular magnifying lens. I discovered that a circular car wax applicator was a perfect fit so I use one for a dust cover for the lens. When I need to use the lens, I don't want to lay the cover in the workbench grunge so I glued a magnet to the material and now I can just stick it on one of the articulating arms. It remains clean and is right to hand when I want to replace it.

Glue a magnet to the corner of a shop towel and you can throw it at any ferrous surface and it will stick. If you use super-glue, you can rescue the magnet when discarding the towel by soaking in a little acetone.

These magnets from Harbor Freight...

https://www.harborfreight.com/10-pie...ets-67488.html

are cheap and scary strong. They're about 7 mm diameter.

**rgsparber** · Dec 31, 2018, 12:18 PM

Marv,

Got to be careful with 1/4" diameter magnets fit into 1/4" holes cut by an end mill. At least the magnets I have are +/- 0.004". If the magnet is too tight a fit, it can shatter.

Do you have any pictures I can include with your descriptions?

A variation on gluing the magnet to the towel would be to glue the magnet to a "binder clip". Then just unclip the towel when it must be washed.

Those HF magnets are $2.79 for a stack of 10 magnets so 28 cents each. I didn't see a pull spec. K & J has that size for 47 cents each with a pull of 3.36 pounds. Of course, S/H is high if you only buy a few magnets.

Rick

**mklotz** · Dec 31, 2018, 03:51 PM

Originally Posted by rgsparber

Marv,

Got to be careful with 1/4" diameter magnets fit into 1/4" holes cut by an end mill. At least the magnets I have are +/- 0.004". If the magnet is too tight a fit, it can shatter.

Do you have any pictures I can include with your descriptions?

A variation on gluing the magnet to the towel would be to glue the magnet to a "binder clip". Then just unclip the towel when it must be washed.

Those HF magnets are $2.79 for a stack of 10 magnets so 28 cents each. I didn't see a pull spec. K & J has that size for 47 cents each with a pull of 3.36 pounds. Of course, S/H is high if you only buy a few magnets.

Rick

I guess the magnets are slightly undersize. They drop nicely into the holes carved with the endmill.

Sorry, no pictures.

I had thought of the binder clip idea as well but dismissed it fearing the sharp edges of the clip might chip paint on some of the better tool rollarounds. Actually, there's no need to get the glue off the magnet. Just cut it off the old towel and glue to the new one; a few layers of built-up towel aren't going to matter. Wash a shop towel? Sorry, my OCD is bad but it doesn't extend that far. A pack of 50 goes for ~$13, ($10.40 with a 20% discount coupon). At those prices they're consumables in Garaj Mahal.

**rgsparber** · Dec 31, 2018, 05:27 PM

Originally Posted by mklotz

I had thought of the binder clip idea as well but dismissed it fearing the sharp edges of the clip might chip paint on some of the better tool rollarounds. Actually, there's no need to get the glue off the magnet. Just cut it off the old towel and glue to the new one; a few layers of built-up towel aren't going to matter. Wash a shop towel? Sorry, my OCD is bad but it doesn't extend that far. A pack of 50 goes for ~$13, ($10.40 with a 20% discount coupon). At those prices they're consumables in Garaj Mahal.

Maybe "washing" is an overstatement. I use waterless hand cleaner to degrease my hands and then spray with water and wipe on my towel. About every 6 months it is loaded with gook. Soak it in a bucket overnight, rise with hose, and let the sun dry it.

Rick

**wizard69** · Dec 31, 2018, 07:09 PM

I suspect you missed a common usage, that is to fasten notes, drawings and the like to machine tools.

Another idea that just came to mind is to fasten solar poweredcalculators to Machines and work station. At work we have used Velcro for this. These days everybody has a calculator in their pocket due to smart phones, however it hard to beat a calculator that is always ready to go.

**mklotz** · Jan 1, 2019, 10:20 AM

Removing coin batteries from devices like calipers can be tricky. Prying out with a metal tool risks shorting the battery and any prying tool risks damaging the delicate battery contacts or the circuit board. The solution is to glue a small magnet to the end of a pencil-sized dowel. The battery cases are steel so the magnet will easily pull the battery straight out without bending contacts. Use the same tool to install new batteries. Once in place, hold the battery down with the end of a chop stick while pulling the magnet away.

Save this tool you've constructed. Put a pencil clip on it and stick it in your pocket next time you go to the big box store to buy "brass" screws or other hardware. You might be surprised at how much magnetic brass is being mined in China.

These rectangular block-shaped magnets from HF...

https://www.harborfreight.com/2-piec...cks-98406.html

are also very useful.

When making models or prototypes from cardboard, thin wood or plastic they can be used to make an assembly tool. Cover a sheet of steel with wax paper so the glue doesn't stick. Then use the magnets as clamps to hold down the construction material as it dries. With the rectangular block magnets it's easy to build vertical "walls" to use to form right angle constructions. (Alternatively, if you have an angle plate, use that.) The magnets can be waxed with floor wax to prevent glue from adhering to them.

One of these magnets slipped into a shirt pocket can serve as a poor man's version of my shop bracelet...

http://www.homemadetools.net/forum/shop-bracelet-70090

If installing or removing something up on a ladder, the required small hardware (screws, washers, nuts) can be stuck to the outside of the pocket where they are immediately to hand when needed. With a little thought you'll think of other situations where this trick can be helpful.

Many battery-operated tools such as electric drills and screwdrivers have permanent magnet motors. Often enough magnetic attraction reaches through the plastic case such that one of these block magnets will stick to the exterior of the case where it can be used to hold driver points, drills and the like.

My grandson dropped a tiny (about #1 size) screw from a toy into the carpet in the family room. We glued three of the block magnets to a freebie paint-stirrer stick and made a magnetic "broom". He retrieved the screw along with two straight pins and three bearing balls from a failing roller on one of the dining chairs. (I'm betting that that chair shows up on my honeydo list very soon.)

**rgsparber** · Jan 1, 2019, 10:20 AM

Originally Posted by wizard69

I suspect you missed a common usage, that is to fasten notes, drawings and the like to machine tools.

Another idea that just came to mind is to fasten solar poweredcalculators to Machines and work station. At work we have used Velcro for this. These days everybody has a calculator in their pocket due to smart phones, however it hard to beat a calculator that is always ready to go.

Great ideas. I put them in the next release of the article.

Thanks,

Rick

**bruce.desertrat** · Jan 1, 2019, 11:00 AM

I have one of those little round magnets on the top of my drill press, holds the chuck key right there.

A good source of scary strong magnets is old computer hard drives. They're fiddly to disassemble (but you then have a large collection of nice little 4-40 torx 8 screws as well) buy they're very strong and come conveniently (or inconveniently, depending on your needs) attached to a sturdy steel back with pre-drilled mounting holes. The best come out of old 3½" SCSI server grade drives. One I have in our kitchen holds about 30 pages of recipes to the fridge. attached are common examples.from a 2¼" laptop drive, some consumer grade drives and the thick ones are some of those server SCSI drives. You most definitely don't want those bigger ones tocome together at any speed, they shatter into a billion highly magnetic, razor-sharp shards.

**bobneumann** · Jan 1, 2019, 01:57 PM

At the risk of being slightly off topic: I made my own version of a carriage DRO for my lathe from a stainless 8" digital caliper. One jaw is screwed to a bracket that clamps to the front way. The other jaw hangs out in space when not in use, and attaches very nicely to the carriage with a 13mm neodymium magnet when in use. It's really very snug and tight and reliable, and very easy to attach and detach.

You can see the remnants of JBweld, which I originally had used to attach the magnet to the caliper jaw. But it actually made alignment more difficult, and the magnet sticks to the caliper head so nicely that it's much easier to just leave the magnet on the carriage and stick the caliper head to the magnet.