22 Eylül 2012 Cumartesi

The Magnet Test

The Magnet test is used to distinguish ferrous from non-ferrous metals; or, rather obviously, magnetic metals from non magnetic metals. 


I found also, that it is important to have a magnet that works for you! If you need help finding a magnet, I suggest you check these cheap sources of where to find free magnets! Another useful test for scrappers is THE SPARK TEST


The Magnet will become your weapon, and with it you will sort ferrous and non-ferrous. 

Follow these steps:
  1. Step One: Find a metal sample
  2. Step Two: Find a magnet
  3. Step Three: Place the magnet against the metal sample.
  4. Step Four: Pull the magnet away from the metal sample.
  5. Step Five: Obey the magic rule...
     If the magnet sticks to a metal alloy, it is a ferrous (or nickel or cobalt) alloy. 


Ferrous Metals

Ferrous metals are alloys of iron, and they usually stick to a magnet... BUT a common misconception is that steel is the only metal that attracts a magnet; This mistake can be an expensive one. There are actually 3 (THREE) common elements that pull to a magnet, and those are iron, nickel, and cobalt.  (there are some others, but they are mostly rare earth metals. For example, gadolinium)

These three metals are known as ferromagnetic (ferro- the latin root for iron) at room temperature. Ferromagnetic, for all intents and purposes, is just a fancy way of saying "strongly attracts a magnet." So ONLY iron, nickel, and cobalt will have a force exerted on them by a magnet, nothing else.

Iron, is a common, cheap metal; Nickel is an expensive metal, more so then copper; and cobalt is even more expensive, more so then nickel. If your magnet gets pulled to a metal alloy, it contains iron, nickel, or cobalt (usually just iron).

Many other compounds (non-metals) can be magnetic, but these are easily distinguished from a metal alloy as they are usually ceramic; for example, ferrite.

Be warned; things that are not attracted to a magnet can still contain iron, nickel, cobalt, or a combination. Take for example, 304 stainless steel. It contains both iron and nickel and yet, it doesn't attract a magnet! (Actually, there are many different types; find out why some types of stainless steel  aren't magnetic!)

Metals that stick to a magnet that you should know of:

  • Iron / Steel / Ferrous
  • 4xx Series Stainless Steel
  • Scrap Carbide (made of tungston cabide in cobalt)
  • Nickel
  • Cobalt

Non-Ferrous Metals


Non-ferrous metals are generally non-magnetic (except for nickel and cobalt). It is worth learning to identify these scrap metals:

  • Aluminum
  • Lead
  • Copper
  • Brass
  • Zinc
  • Magnesium
  • Pot metal 
  • Chromium (used in Stainless Steel)
  • Pewter
  • Titanium
  • Mercury
  • Gold (found in Scrap Computers)
  • Silver 
  • Platinum (found in Scrap Catalytic Convertors)

As you guessed, these metals are very valuable and will be easily distinguished from ferrous metals with nothing but a magnet.  Only after you have been learning for a while, will you be able to sort metals by simple sight and touch. http://scrapmetaljunkie.com

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