Magnets are such useful tools, and if you know where to look, they can be aplenty! These 5 places are a “must-check” whenever I need magnets for a project.
- Hard Drives
Hard drives are worth quite a bit simply as scrap hard drives because they are made of aluminum and non-magnetic stainless steel. But, if you take the time to pull them apart, you will find 2 large neodymium super-magnets!
Proper disassembly is recommended, and this often requires a precision
Torx bit set, found easily and cheaply on eBay.
These magnets generally have a magnetic field strength of 1 Tesla, and that means they are really able to show some pulling power. Nowhere else can you get such large free neodymium magnets!
Each magnet is coated with nickel, and then epoxied onto a magnetic shielding super alloy. This ally is called permalloy, or mu-metal, and is approx. 70% nickel. What makes this alloy so special? It literally stops the magnetic pull in its tracks. Try it next time you have a chance: stick something to the magnet, then pull it off and try to stick it to the other side of the magnet (where the shield is) and be amazed!
- Magnetrons in Microwaves
These magnets are my favorite when sorting scrap metal via the magnet test. If you pull apart a microwave, you probably see notice the large transformer right away, and maybe even the fan motors or wires, but do you ever look at the magnetron?
After doing a write-up of How To Scrap a Magnetron, I heard more about how much people love the magnets from these things then about the copper! And it makes sense; they are big, easy to hold onto, and strong enough to get the job done! Each magnetron has 2 large ferrite magnets, and although they are weaker then a super magnet, they often prove more useful!
All speakers have the same main components: a head, some copper windings and a magnet. Some speakers are hard to take apart, others are not that bad. But be careful, if a speak magnet is glued into place, it may not be worth trying to pull out. These magnets are ferrite (like magnetron magnets) but don’t require ripping open a microwave.
The downside of these magnets is that they are harder to pull out ( in my opinion). And the biggest magnets are found in big speakers, which I don’t run across all that often, unless I seek them out.
- Electric motors
There are many types of electric motors, and all of them rely on magnetic force. Many motors have permanent magnetic fields made by permanent magnets. The more permanent magnets you have in a motor, the more powerful it is (generally) so this makes electric motors a great place to look for magnets.
To tell which motors have permanent magnets, they will be the ones that give resistance when you try to spin their shaft. If the shaft spins freely, then there are no magnets in the motor.
- Electro Magnets!!!!
You see big versions of these magnets every day at a scrap yard. They convert electricity into magnetism, and are used in everything from door bells to washing machines.
Making an electromagnet is simple; you just need electricity, wire, and a steel rod of some sort.
I made my own electromagnet by gathering some of the necessary materials. Grab a scrap phone charger (or computer charger, ect… You just want scrap power supply that will turn your AC outlet into DC current) and cut off the end (not the plug). Also, grab a steel nail, bolt, or rod.
Twist together the two severed ends of the charger, and split the two lines apart so you have one large loop. Then, wrap the nail/bolt/rod, so it looks like the picture below.
Once you plug your charger in, you will notice the magnetic pull of the rod. The rod will become more magnetized if you have more DC current running through the wire (by using a different charger), or if you wrap it a larger number of times.
I made an electromagnet just like this, wired it up to a light switch, and mounted it above my work bench. Now I have an extra strong magnet that I can shut on and off!