Magnetics.

If you are interested in obtaining some NEODYMIUM SUPER SUPER magnets, please email

synthetiklone (at) yahoo . co . nz , for more information.

or alternatively visit www.trademe.co.nz, there may be some listed there.

The following Neo magnets are nickel plated (chrome), not gold in colour, and the poles are on the top/bottom flat surfaces. The thicker they are, the more powerful. The 10mm ones are the strongest.

15x20x2mm	15x20x3mm	17x20x3mm	17x22x4mm	26x31x10mm	30x35x10.5mm

Above is shown various ex-hard drive magnet variations, there are many more.

A stack of 5 10mm Neo magnets are almost impossible to seperate. A stack of 10 and you can actually feel the earths magnetic poles pulling the stack!	A ring of 10mm Neo magnets alternating poles assembled on a steel disc gives you the start of a very powerful axial generator.

Warnings: These are not your ordinary old weak steel magnets you usually see. They are SO strong the larger ones are very hard to pull apart, and the smaller ones are not much easier. You have to slide them apart. They are pretty dangerous when they come together. They can give you a nasty pinch, or jam your fingers between them - it hurts and can cause a bruise if you are not VERY careful. Not recommended at all for small children to play with. Also, if the bigger ones are allowed to snap together, the force can smash them to bits. Be careful not to allow this to happen, as small fragments can fly out and get lodged in your eyes. Also, these magnets are SO strong, they can erase your EFTPOS bank cards, and blank any other form of magnetic storage, including video cassettes / tapes, magnetic computer backup media (not CDs, as they are optical!) Also, if they are bought within a metre of your TV or computer monitor, they can cause bright colourful blotches to appear all over the screen. Sometimes these coloured areas will stay on your screen as you have magnetised the inside of the screen, and it will have to be professionally demagnetised with a degaussing wand. Most computer monitors have a degaussing button you press to clean the picture, this may have to be performed many times to get the picture colour back. Standard televisions dont have this feature.

Neodymium magnets available in all shapes and sizes.

Some other possible uses of super magnets :

Springless springs - opposing magnets repel
Magic human compass - blindfolded and able to find north or south pole by feel alone
Hold directions to my motorcycle gastank so they don't come off at 100kph
Making a muscleman look like a fool by not being able to separate a silly stack of magnets by pulling them directly apart
Holding my advertising logos on the side of my truck
Quickly erase secure data on old computer hard drives
Quickly erase ANY form of magnetic storage medium, tapes, videos etc
Magnetic art mobile clockwork and pendulums
Magnetic art decoration, using LOTS of steel balls with magnet under plate/table
Vibrating super sub-base, have your stereo literally thump the sound into the air, realistic explosions etc
Safely removing parts from the punch press
Cleaning up chips in the machine shop.
I use them on survey stakes so that metal detectors find them from a distance.
Diamagnetic Levitation
Violin mute. Put small discs on each side of the bridge to add mass and quiet the violin.
Slot car traction
Holding down a car cover
Pulling dents
Holds the outhouse door shut
To find steel pennies
Attaching locating transmitters to motor vehicles
Locating property corners
Jewelry clasps
Re-charging my alnico magnets
Hanging tapestries in a warehouse
Hanging art and pictures from the walls
M ount my CB radio under the dash
With one magnet and a ball bearing I remove dents from brass musical instruments
I put them in my sluice box to seperate the magnetite from the gold
H olding all the lathe tools to the lathe
Magnetize my tools
A cool clock with ball bearing hands
Magnetic stirring device
Building a chaotic pendulum
Bike light generator
Finding studs through walls, the magnets will stick to the nail heads
Holding things to the ceiling
Christmas presents
Wind power alternator
Magnetic tumbler for finishing jewelry
Entertaining drunk people
Alleviate joint pain
Hold a small vise down
Picking up nails in the driveway
School class project
Hold lines and tape in place on steel hull when shipfitting.
Retrieving all the tools my helpers drop in the bay. I'm gonna glue them to their boots and make them walk the bay at low tide.
Cleaning nails from the horse pasture
Oil filter in my motorcycle - attracts all the tiny iron particles in the oil
Guitar pickups
Attaching certain tools under my hood
Holding the roof down on my shed :)
Holding safety shield on machine tools
Hang skillets
Use for holding Trailer lights on rv towed vehicle.
Levitation
Knife sheaths
For classroom demonstrations and to motivate students to study electricity and magnetism
Picking my keys and everyone elses out of the bottom of a pond
Treasure hunting
Experimental loudspeakers
Nice big homemade ammeters
Raising the Titanic :)
I invented a system to drasticly improve fuel milage. I stick a couple on my front bumper. When on the motorway, I accelerate - into the back of a large semi 18 wheeler. CLUNK- my car becomes attached. I then turn off my engine. Sure beats cruise control! A light tap of the brake pedal seperates me. This is really probably not a good idea to actually do. Please dont try it !

When camping - I hang my wet clothes from the van to dry, with magnets.
Cleaning up the microscopic metal fragments in the oil pan in go-cart racing engines. leave one inside
Small ones make great ear, nose, lip rings, I dont even have to pierce myself
Breaking all the laws of thermodynamics
Biomagnetic therapy
Car top advertizing signs
Studfinder
Holding sheet metal together for welding
Dampening for seismograph using eddy currents in a block of aluminium
Hold down a tarp to the roof for a sunshade
Magicians illusions
Dragging lakes for missing keys, lures, jewelry-etc
Use in a woodworking jig.
Hanging tools
Cleaning my fishtank glass - from the outside
Hiding keys and other stuff in my car
Hold string to steel hull of a boat for measurement
Motor experiments
Education
Anti-matter containment :)
Water Conditioning
Diesel purification - better mileage
Longitudinal force experiments
Making your own maglev train
Production jig fixture
Use to retrieve dropped objects in the water, ocean, pond, pool
Erasing tapes
Recharging alnico magnets
Parking lot clean up
Perpetual motion machine
H omemade alternators - for wind or hydro power
Bending cathode rays in an old TV - pretty colourful pictures (possibly permanently damages TV)
Induced movement of 100 micron paramagnetic beads for biomedical applications
Erasing my wifes credit cards
Separating magnetic black sand from gold pan concentrates
Setting planar blades
Sticking really BIG THINGS to the fridge
Healing therapy - have been known to cure headaches
Collecting and refining iron ore from beach sand, and making ferro fluid

More information on magnets

AlNiCo. (Aluminum-Nickel-Cobalt) for medium strength and excellent machinability. Developed in the 1940s and still in use today. They perform much better than plain steel, but are much weaker in strength (lower B, Br and BHmax) and must be carefully stored since they are prone to demagnetization. Contact with a NdFeB magnet can easily reverse or destroy the field of an AlNiCo magnet.

Ferrite (Ceramic). Also known as 'hard ceramic' magnets, this material is made from Strontium or Barium Ferrite. It was developed in the 1960s as a low-cost and more powerful alternative to AlNiCo and steel magnets. Less expensive than NdFeB magnets, but still very powerful and resistant to demagnetization. Useful everywhere. Ferrite magnets are lower in power (B, Br, BHmax) compared to other formulations, and are very brittle. However, they have very high Hc and good Tc (see below), and are quite corrosion-resistant. A very cost-effective choice.

The biggest differences between ferrite magnets and rare earth magnets is that rare earth magnets are much stronger.
The intensity of magnetization and the coercive force are elements determining the performance of permanent magnets. Since rare earth magnets contain iron and cobalt in the state not containing oxygen, their magnetization is large. In addition, magnetization of rare earth magnets has a strong force (coercive force) aligning the magnetism in one direction, so they are much stronger magnets than ferrite magnets.
Since they have about 10 times the performance of ferrite magnets in total energy per volume, rare earth magnets are used for powerful magnetic circuits that could not be conceived of until now.

Rare Earths

The metal elements called "rare earths" were discovered by J. Gadolin of Finland about 200 years ago in 1794. He discovered yttria (Y2O3) in minerals extracted in Sweden and gave them the name rare earths (here, earths means alumina, lime, etc.)
However, the rare earth elements are not actually rare. There is more cerium (Ce) on the Earth than tin (Sn) and more ytrium (Y) and neodymium (Nd) than cobalt (Co) and lead (Pb).
Image at right shows amount of various elements contained in one ton of igneous rock.

Neodymium magnets - NdFeB (Neodymium-Iron-Boron).

Also called NIB or NEO magnets they are composed of neodymium (Nd), iron (Fe) and boron (B) they boast the highest performance of all rare earth magnets. This formulation is relatively modern, and first became commercially available in 1984. As neodymium is relatively abundant, the cost of these devices is also more reasonable than that of comparable samarium (Sm) magnets. Application of Nd magnets is expanding rapidly in various fields as their cost/performance advantages gain recognition.
Corrosion resistance, formerly considered to be a drawback, has been improved through various types of surface processing, including nickel (Ni) plating. As a result, these magnets now deliver optimal performance for virtually any application. NdFeB magnets have the highest B, Br, and BHmax of any magnet formula, and also have very high Hc (see below for definitions).In almost all magnet applications, NdFeB are the best choice for incredible strength and coercivity at a reasonable price. In power generation applications, NdFeB magnets can be expected to give 4-5 times the power output of ceramic magnets.

Samarium Magnets - SmCo (Samarium Cobalt).

The thermal characteristics of samarium magnets are superior to those of Nd magnets, maintaining high magnetism and reliability even in challenging high-temperature (high Tc) and opposed magnetic-field environments. Developed in the 1970s, these were the first so-called 'rare earth' magnets. They are the most expensive magnet formulation and are almost as powerful as NdFeB magnets. Sm magnets also offer high Curie temperatures with less coercivity temperature change-properties unmatched by other magnets.

Magnet Facts and Measurements.

Magnet Strength Measurements (B) The units for measuring the field strength (flux density) of a magnet are Gauss or Tesla. 1 Tesla = 10,000 Gauss. The Earth's magnetic field is on the order of 1 Gauss. There are different ways to classify and measure field strength:

B (flux density): This is the measurement (in Gauss or Tesla) you get when you use a gaussmeter at the surface of a magnet. The reading is completely dependant on the distance from the surface, the shape of the magnet, the exact location measured, the thickness of the probe and of the magnet's plating. Steel behind a magnet will increase the measured 'B' significantly. Not a very good way to compare magnets, since B varies so much depending on measurement techniques.

Br (residual flux density): The maximum flux a magnet can produce, measured only in a closed magnetic circuit. Our figures for each magnet are provided to us by the magnet manufacturer. They are a good way to compare magnet strength, but keep in mind that a magnet in a closed magnetic circuit is not doing any good for anything except test measurements.

B-H Curve: Also called a "hysteresis loop," this graph shows how a magnetic material performs as it is brought to saturation, demagnetized, saturated in the opposite direction, then demagnetized again by an external field. The second quadrant of the graph is the most important in actual use--the point where the curve crosses the B axis is Br, and the point where it crosses the H axis is Hc (see below). The product of Br and Hc is BHmax. If we have these measurements available, they are provided to us by the magnet manufacturer. Very complicated and expensive equipment is needed to plot a B-H curve.

A sample B-H curve:

Magnet Quality (BHmax): The quality of magnetic materials is best stated by the Maximum Energy Product (BHmax), measured in MegaGauss Oersted (MGOe). This is because the size and shape of a magnet and the material behind it (such as iron) have a large effect on the measured field strength at the surface, as does the exact location at which it measured.

All of our Nickel-plated NdFeB magnets are grade N35 (BHmax=35 MGOe) and all of our Gold-plated NdFeB magnets are grade N45 (BHmax=45 MGOe). This gives about a 5% difference in strength, and a 150% difference in cost. It is wise to balance your magnet strength needs by cost too. Other magnets are measured the same way, a grade 8 ferrite magnet (grade C8) has BHmax=8 MGOe.

Coercivity (Hc): This measures a magnet's resistance to demagnetization. It is the external magnetic field strength required to magnetize, de-magnetize or re-magnetize a material, also measured in Gauss or Tesla.

Curie Temperature (Tc): This is the temperature at which a magnet material loses it's strength, permanently. Another useful number (if available) is Tmax, the recommended maximum operating temperature. Above Tmax (around 266 deg. F for most NdFeB magnets) a magnet will start ot lose its power, and at Tc all power is lost.

Corrosion: NdFeB magnets are susceptible to corrosion. The 'Fe' in the name stands for Iron, and it rusts! Many of our magnets come with a Nickel, Zinc, Gold or Epoxy coating to protect them from moisture. If the coating is damaged, the magnet could rust if exposed to water or humidity. If this is a concern to you, you can easily add another layer of protection by dipping the magnet in epoxy or plastic coating.

Drilling and Machining: Neodymium magnets are by nature very hard and brittle. Although they can be cut, drilled and machined, it should ONLY be done by folks who are experienced with ceramics. If the magnets get over about 260 deg F, they will lose their magnetism permanently. They are flammable, and it is not difficult while grinding or machining to get them (or the chips and dusts from cutting) so hot that they ignite. If they do ignite, the fumes are toxic and the material burns very fast and hot, like Magnesium! In our experience any machining of these magnets should be done with diamond tools under lots of coolant with good ventilation and the risk of fire in mind.

Patents: NdFeB magnets are a relatively new invention, they first became commercially available in 1984. All NdFeB magnets are currently protected under international patent. All of our magnets are either surplus from various industries, or new, legal, licensed material.

Manufacturing: NdFeB magnets are complicated to manufacture. The powdered NdFeB material is packed in molds, then sintered. The non-magnetized 'magnets' are then shaped to the correct size and plated. To magnetize them, they are placed in a very expensive machine that generates an extremely high-powered magnetic field for an instant, using high-voltage capacitor discharge and coils. The polarity of the finished magnet depends on how it was oriented in the magnetizing machine, and how the particles in the sintered mixture were oriented.

Hope this helped you understand and give you more ideas for experiments with magnetism.