Re-Magnetize a Tool





Introduction: Re-Magnetize a Tool

About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first ...

This is a magnetic grabber. Its magnet has lost most of its strength so that it will hardly pick up a screw without the screw shaking off of the magnet.

This Instructable will show how to make the magnet stronger while maintaining the original magnetic polarity.


  • Small gauge insulated wire
  • Electrical tape


  • Round shank screwdriver
  • Magnetic compass
  • Old flashlight batteries
  • Wire cutter
  • Knife

Step 1: Wind a Coil

The magnet is in the smooth end of the grabber. I want to wind a coil of small gauge insulated wire around the smooth end. The wire is plastic coated, but enameled wire would work as well. I wound a coil almost the full length of the smooth end, although less would have been fine, since the magnet is surely shorter than the smooth end. I did not count the turns of wire, but wound three layers.

Step 2: Check Magnetic Polarity

I want to strengthen what magnetism remains in the magnet. I do not want to reverse its polarity so that I must take it down to zero and then build it up in the reverse polarity.

I am using a magnetic compass to determine the polarity of the magnet in the grabber. I turned the compass so it is not on the earth's North - South axis and brought the magnet near to the compass. The indicator swung so that the magnet attracted the South pole of the magnet in the compass.

Step 3: Determine the Electrical Polarity Needed

I taped my coil of wire so it would not unravel. It is wound loosely enough that I was able to slip it off of the grabber and onto a screwdriver with a slightly smaller diameter.

I energized the coil with an old flashlight battery. One lead on my coil is shorter than the other and I found if I connect the shorter lead to the positive (+) tip of the battery, the screwdriver temporarily becomes a magnet that attracts the South pole of the magnet in the compass. Now I know how to connect the batteries to strengthen the magnet in the grabber.

Step 4: Magnetize

I slipped the coil off of the screwdriver and back onto the end of the grabber so the shorter lead is nearer to the forward end as on the screwdriver in the last step. I used two old flashlight batteries to energize the coil, and I held the leads from the coil by hand for a couple of minutes. I could actually feel some warmth at the negative (-) connection held by my thumb.

3 volts was enough to do what I needed. If I had connected the coil to a car battery, the results would have been faster to achieve, but I may have melted the insulation on my coil, too.

I stopped to check the strength of the magnetism in the grabber. When it seemed strong enough to do what I want to do, I disconnected the batteries and removed the coil.

Step 5: Test

I am holding the magnetized end of the grabber so the photo will be more understandable. Of course, I would normally hold the other end when retrieving a screw from some recess into which it had fallen.

My newly re-magnetized grabber can now lift a 3 inch lag screw 5/16 inch in diameter. That is far better than it could do before.

Fix & Repair Contest

Runner Up in the
Fix & Repair Contest



    • Creative Misuse Contest

      Creative Misuse Contest
    • Oil Contest

      Oil Contest
    • Water Contest

      Water Contest

    28 Discussions

    Phil - Your bio resonates with me. I love taking care of the tools I have, making the ones I don't, and doing whatever needs doing with whatever I can scrounge.

    Thank you for this post. I knew how to make an EM, but somehow it never occurred to me to use that to (pretty elegantly) re- or de- magnetize a tool. Duh!

    A second, huge thanks for suggesting the compass. I am much happier knowing that I am working WITH what I already have. I'm a bit embarrassed to do this, but I'd like to add something to that idea. We're in a crazy age where, I suspect, a lot of folks don't have a compass. What they do have is a <sic> smart-phone. These contain and can be used as compasses. (FWIW, my favorite "app" for that purpose is GPS Status for Android. It is dense with simple, useful features, and the program is very small. (In the world of computer programs, smaller is almost always better; bigger is almost always worse.) I don't mean to hijack your thread or advertise a product. I appreciate, and I just want to seize on this, my first opportunity to make a tiny contribution to the wealth of knowledge herein contained.)

    Thanks again, Phil

    1 reply

    I have not tried holding a magnet near to my smart phone to see how the built in compass responds.

    Years ago we visited the USAF Museum in Kettering, Ohio. The museum has a section about life as a POW during different wars. In WW II captured fliers made their own compasses for use in a possible escape. They magnetized a sewing needle by stroking it with a magnet. They attached it to a disc of cardboard like you see on the back of a legal pad. The cardboard disc floated in water when needed. They made a little cup for the water using a phonograph record. They softened it with the flame of a candle and pressing a broomstick into the record with a slightly larger hole in a piece of wood on the other side of the record. This made an impromptu press for making a small cup from the phonograph record. Water could be added just before use. Someone who did not have a compass could do something like this.

    Thank you for your kind comments.

    Very good idea.

    I plan to magnetize some old tools this way.

    Thanks for this :)

    1 reply

    Thank you for looking at this. Electromagnetism is one of a few ways to magnetize a tool. Others include storing a tool in line with the earth's magnetic lines of force between North and South Poles and storing a tool in a drawer next to a strong magnet. Yesterday I was in a restaurant. When I picked up my butter knife, the handle of the spoon came with it. The knife was magnetized, although not from the factory, I am sure.

    Thank you for info on this as it is much needed around here off & on again.Must say a very nifty idea. ;-)

    1 reply

    It is always disappointing when an allegedly magnetized tool is not up to the task because the magnetism has faded.

    thank. You for the info, I like the use of the compass to keep from possibly demagnitizing the tool before remagnitizing it. A useful step indeed

    1 reply

    Thanks. A lot of this Instructable is based on what I saw my father do. The part about the compass needle was my idea. I am glad it is or will be helpful to you. Thank you for looking and for commenting.

    I didn't make it but I'm glad I found you! As someone who would rather make a solution rather than buy one I think you do great things!

    1 reply

    Thank you. Instructables is a fun site, especially if someone can find help and save effort or money through something published by you.

    I was born just after WW II. We always had enough, but not much extra. My father had a few tools, but only a few. We also had scraps of wood on a pile. When I wanted something, I tried to make it. Usually that worked out pretty well, even if the results looked a little rough. Quite a few decades later I am still doing that, but have a few tools my father never had.

    Thanks for this very innovative using simple parts to magnetize definitely using this when the screwdrivers are down n out

    Phil it was great, I was successful in re magnetizing my old screwdriver, Thanks a million.

    1 reply

    Thank you for trying this and for reporting back. It is a little frustrating to have a magnetic tool that is no longer adequately magnetized, and a very good feeling when the tool works like new again. Good for you.

    Thanks for the information, I have a relatively new Philips that isn't holding screws anymore. I'll be trying this soon.

    One comment: To anyone else considering this DO NOT use a car battery. Yes it's 12 volts instead of 3 volts, but it also has a LOT more amperage and will quickly make a mess in this scenario. You will at a minimum burn your fingers and melt/burn the sheathing from your wire if you connect the two ends of a copper wire to the + and - terminals of a car's battery.

    1 reply

    My father remagnetized a tool many years ago and did use a car battery in the vehicle. Even though he connected the wire to the battery for only seconds at a time, the insulation on his much heavier wire did melt.

    On additional reason I did not want to use a car battery is that today's cars have lots of sophisticated and sensitive electronics. Things like a short on one part of the car sometimes create problems on another part of the car. I was thinking of warnings about welding on a newer car. Sometimes the electronics come to be fried.

    Thank you for your comment.

    A very well reasoned ible including where you point out the true magnetic North is not in line with your tool.

    As a fellow elder, I enjoy this magnetic pick up and release tool which is fun finding things near boat docks and other places without bending or painful kneeling postures. You can see the tool in action at

    1 reply

    Thanks. I began an Instructable using some left over Harbor Freight magnets and a wooden pole about four feet long. I use it to pick up screws and scraps from the shop floor. I planned to use a split magnet from a hard drive to make a junior version for a grabber like this one. That was while I thought this one was irretrievably shot and kaputt. Now that this one works better than it has in a long time, I am back to procrastinating.