Info Articles

Magnetism: What Metals Are Magnetic and What Are Not?

magnet picking metals in scrapyardEver wondered how scrapyards sort mountains of junk to separate the recyclables from the non-recyclables or to identify which materials are reusable for which applications? They use a variety of techniques from manual to machine-aided segregation since they are dealing with different types of materials.

One very effective technique that almost all big scrapyards use is magnetization. By holding up a powerful magnet above junk, iron-containing or “ferrous” metals can be extracted, leaving behind “non-ferrous” metals, such as copper, brass, and bronze. Of course, plastic items won’t be magnetized as well but they are easy to identify and separate.

How Magnetism Works

Humans have known about magnetism for thousands of years, and our understanding of it has given way to various forms of technology that support some of the most important industries of our time. Because the forces at work in magnetism are invisible, it can easily be mistaken for magic or supernatural occurrence. Unsurprisingly, a lot of magic tricks involve the use of magnetism due to its physics-defying features.Disappointingly for the superstitious, magnetism is pure science.

The best way to understand how magnetism works is by looking through the electron microscope and study the motion of electrons. An atom consists mainly of three types of elementary particles—protons and neutrons, which comprise the nucleus, and electrons, which orbit the nucleus and fill the atom’s orbitals.

Electrons normally come in pairs, both of which spin but in opposite directions. Electrons spin and movement across the atom’s orbital creates a magnetic field. Because a pair of electrons spin in opposite directions, they cancel each other out, eliminating their magnetic capability. Some atoms, however, have unpaired electrons that share the same orbitals. These electrons spin in the same direction, creating a force that either attracts or repels other atoms with unpaired electrons.

Types of Magnetism

Because a lot of different things can happen to the electrons of an atom when exposed to external forces, magnetism may occur in different ways as well. Here are some of the common types of magnetism that you may encounter when trying to magnetize different types of materials.

  • Diamagnetism

    – All materials have a natural tendency to oppose an applied magnetic field, except those that possess paramagnetic properties. This reaction to external magnetization is called diamagnetism.

  • Paramagnetism

    – Some materials have a tendency to enhance an external magnetic field and in the process cancel out their diamagnetic reaction. Each of their atoms have one unpaired electron that is free to align its magnetic moment in any direction where an applied magnetic field exists.

  • Ferromagnetism

    – Like paramagnetic materials, ferromagnetic materials have unpaired electrons on their orbitals. The only difference is that the intrinsic magnetic moment of these unpaired electrons also have the tendency to orient parallel to each other to maintain a low-energy state, allowing them to maintain magnetic force even in the absence of an applied field.

  • Antiferromagnetism

    – Obviously, this is the opposite of ferromagnetism. The intrinsic magnetic moment of the unpaired electrons tends to orient opposite each other instead of parallel to each other. As a result, they don’t create their own magnetic field and are completely reliant on applied field to generate magnetic attraction.

  • Ferrimagnetism

    – Some materials have qualities of both a ferromagnet (retaining magnetization in the absence of a magnetic field) and an antiferromagnet (sometimes rely on external magnetization). Magnetite, the first discovered magnetic substance and was originally believed to be a ferromagnet, is actually a ferrite.

Types of Magnet

Now that we understand how magnetism works on a subatomic level, we can conclude that some metals are naturally magnetic and that the magnetic properties of certain metals can be manipulated. This means not all metals are magnetic but can be alloyed with other metals to become one. Magnetic metals can be classified into three types:

  • Temporary Magnets

    – These are metals that become magnetized when exposed to a magnetic field and lose their magnetism when the magnetic field is removed.

  • Permanent Magnets

    – Some metals have natural magnetic properties. They can attract metals that exhibit the same type of magnetism as they do. Best examples include alnico (an alloy of aluminum, nickel, and cobalt) and ferrites (iron oxides combined with nickel, strontium, or cobalt).

  • Electromagnets

    – When you run an electrical current through a coil with a metal core, such as copper, you create a magnetic field, which disappears when the current is shut off.

Meanwhile, there are numerous applications involving the use of metal where magnetism isn’t necessary. Therefore, it is crucial to identify not just metals that can be magnetized, but also metals not attracted to magnets. Some of the most common types of metal attracted to magnets include iron, cobalt, nickel, and some alloys of rare earth metals.

Best examples of non-magnetic metals include copper and its alloys, such as bronze and brass. In fact, they are segregated from scrap by using magnetism to extract magnetic metals like iron mixed with them. Then again, copper is also a kind of metal used in magnets, particularly in electromagnets, due to its high electrical conductivity.

If you are planning to use metals in your project, it’s important to take note of what metals are magnetic and what are not. To be absolutely sure that you are picking the right materials, consult with experts like Rotax Metals. They can give you advice not only on the most ideal type of metal to use but also the exact grade and thickness.


Muntz Metal

What is Muntz Metal and Where is It Used in Our Everyday Lives?

Brass Cookware

The use of metals in everyday life is nothing new in human history. In fact, humans have been using metals since 5000 BC. Given this, it’s not surprising many people are familiar with common metals like copper, steel, bronze, and the like–but have you ever heard of Muntz metal?

Although Muntz metal isn’t a term that you come across very often, the use of Muntz metal is common throughout the modern world. Now, you might be thinking to yourself, “what is Muntz metal and where is it used? Before we dive into its uses and applications, however, let’s take a quick look at the history and composition of muntz metal.

What is Muntz Metal?

Muntz metal isn’t actually a unique type of metal per se. It is actually a type of brass alloy. If the typical brass you are familiar with is comprised of 67% copper and 33% zinc, Muntz metal is an alloy comprised of 60% copper, 40% zinc, and trace amounts of iron. The process of creating it is also quite unique since Muntz metal is manufactured by melting copper first and then introducing zinc and trace amounts of iron. This mixture is then placed into clay-line pans and then ladled into ingot molds.

George Fredrick Muntz, an English businessman from Birmingham, England, developed the metal in the 1830s, hence the metal’s name. This discovery was revolutionary at the time. Intercontinental travel during the 1800s was mostly done via large wood ships made of oak. Although wood is known to float on water (buoyancy), it was also susceptible to damage from shipworms. These worms had a nasty habit of burrowing into oak underbelly of large ships. From there, shipworms would slowly eat away the wood. As you can imagine, this presented a significant risk for seafarers and ship passengers, especially when travel between some countries could take months.  Muntz metal was seen as a solution to this problem.

Why Muntz Metal?

One of the key properties of Muntz metal was its anti-corrosive nature. Due to the specific mixture of different metals, Muntz metal was highly resistant to corrosion in the high seas. Naturally, the issue of shipworms became non-existent as the pests could not bore past the coat of Muntz metal covering ships. Shipworms weren’t the only pests that Muntz metal deterred. Barnacles are another common pest for seafaring vessels. Barnacles are notorious for clinging on to ships and, if there are a significant number of barnacles present, reducing the speed and efficiency of ships. Muntz metal helped solve these issues thanks to a neat chemical interaction with water. When exposed to water, Muntz metal diffuses a chemical that deters these pests from clinging to a ship.

The second reason why Muntz metal was a revolutionary invention at the time was its cost. You may have noticed that Muntz metal uses less copper than traditional brass. This resulted in a much lower mass manufacturing cost for manufacturers. In fact, Muntz metal carried a price tag that was two-thirds of the price of regular brass. This made it faster, easier, and more profitable to mass produce. The best part about Muntz metal for metalworkers and ship manufacturers was that the metal still retained the incredible durability associated with bronze. This meant ship builders received the same exceptional durability at a fraction of the price. It wasn’t long after its discovery that Muntz metal became commonplace in sea vessels worldwide.

What is Muntz Metal Used For?

Today, Muntz metal is still used for many maritime applications, despite the emergence of other similar metals like naval brass. Many shipbuilders still prefer to use Muntz metal for its cost-effective nature and incredible durability. Although only a few ships use Muntz metal as the protective layer of ships, the metal is still used in other applications on a ship, including fittings, pipes, and the like.

Muntz metal has also grown past its initial maritime use. Thanks to its brilliant gold color and corrosion resistance have attracted some furniture manufacturers to use the metal in their designs. Muntz metal is also sometimes used for residential pipes and plumbing since the chemical Muntz metal exudes when exposed to water has also been proven to inhibit the growth of bacteria.

Many of the bolts used in modern machinery are made of Muntz metal. This is mostly due to the price of the material, as well as the fact that Muntz metal can easily be fashioned into various shapes and sizes, making it ideal for manufacturing machinery parts.

Purchasing Muntz Metal

If you are interested in using Muntz metal for your next project, you’re definitely making a great choice. Durable, cost-efficient, and corrosion-resistant, Muntz metal is the perfect choice for a wide range of applications–but don’t buy Muntz metal from just anywhere. Stick to respected suppliers, like Rotax Metals, with decades of superior customer service. These suppliers are more likely to offer you high-quality Muntz metal, allowing you to enjoy all the advantages the material has to offer and giving you the best value for your money.


Understanding the Role of Common Metals Used in Construction

It took millions of years before thinking humans walked the Earth but only a few thousands for them to dominate and modernize it. Thanks to a genius unique to the so-called homo sapiens, our civilization immediately rose to Type 0 in the KARDASHEV Scale. It won’t be long before we reach halfway through to Type 1, which is categorized by the capability to harness the total energy of our planet.

concrete reinforcing bars

Before we get too scientific about the breakthroughs of our civilization, let’s take a step back to see where we owe most of them from. In the last few thousand years, we’ve managed to harness one of the world’s most abundant resources—minerals. From them we were able to produce one of the materials that make up today’s world—metals. The discovery of metals literally jumpstarted the industrial age.

The Use of Metal in Construction

Of the plethora of applications metals are used for, construction remains its largest beneficiary. Construction technology has come a long way since the days when structures were mostly made from carved or cast stones. Back then it was almost impossible to build multiple-story dwellings and manors due to the lack of reinforcing materials in concrete. The tools used for construction were also not strong enough to handle tough structural materials, and so the entire concept of construction was very limited.

When copper was discovered some 10,000 years ago, it was only utilized for basic applications such as making weapons, cookware, and jewelry, and for many good reasons. Not only was extracting copper too complex at the time, but the metal doesn’t really possess characteristics suitable for the heavy construction applications required to kick-start modernity. It took a few thousand years before iron, which makes up most of today’s high-rises and bridges, was discovered.

Common Metals Used in Construction

There are 91 metals in the Periodic Table of Elements. This means over 77 percent of the types of material that make up the Earth is metal. Only a handful of these metals, however, have apparent practical uses. Here’s a short list of metals used in construction.

  • Steel

    – The most prominent among metallic construction materials, steel is vastly used as reinforcement for concrete. It exhibits high tensile strength, which is useful in countering tension forces within a structure. This metal is made of iron and a number of different elements. Carbon, its main additive, improves not only its strength and durability, but also its corrosion resistance, because of course iron is known to be susceptible to corrosion.

    Steel has many different types, each of which suits specific construction applications. Perhaps the most prominent type is stainless steel, which is produced by combining steel with a little bit of chromium. It has very high corrosion resistance, making it a preferred material across a vast range of applications, particularly those that involve exposure to corrosive environments. Galvanized steel follows, which resists corrosion through its zinc coating.

  • Iron

    – Apart from steel, there are other valuable materials than can be manufactured out of iron. For instance cast iron, pig iron, and wrought iron, which are popular materials for making plumbing tubes and pipes. They also play some crucial load-bearing roles in construction but not as critical as those of steel.

  • Aluminum

    – Of the countless non ferrous metals in building construction, aluminum is the second most prominent, next to steel. Its natural corrosion resistance, ductility, and malleability make it perfect for cladding systems on walls that require fewer joints. It is also used for construction applications that involve exposure to corrosive and humid environments. Due to aluminum’s high durability, it is also preferred for structures that are difficult to access and maintain, such as lighting and antenna towers.

  • Lead

    – Although it possesses toxic qualities, lead is still widely used for an array of construction applications. Its toxicity is neutralized by alloying other elements to it. At present, thanks to its ductility, lead is commonly used for making roofs and cladding materials. Most linings for cornices, tanks, copings, gutters and downpipes, flashing, and other metallic components of the roofing system also have lead in them.

  • Copper

    – If you rank metals according to their flexibility, copper would probably get the top spot, and that’s not an overstatement. Examine the properties of copper and you’ll realize that it suits more applications than those of most other popular metals combined. Ductility, malleability, electrical conductivity, machinability, and many other mechanical properties make it a super metal. In construction, it is commonly used in the plumbing system, particularly tubes and conduits that convey gas and hot water. Its alloys are also utilized for cladding surfaces.

  • Brass

    – Copper has many different alloys, and that includes one of the most well-known metals—bronze. But one copper-based metal stands out in terms of usefulness for construction application—brass. You see this metal in different forms from the hinges and knobs of doors to the trims and railings of stairways. They have major part in the complete of a building’s exterior and interior.

The metal industry has grown so big since its advent many thousand years ago and has seen no major decline since, thanks to our insatiable desire for advancement. Unfortunately, like any other products, metals vary in quality and that’s mainly because they are quarried and manufactured by different companies. If ever you are looking to using metals, especially non-ferrous ones, in your future craft or construction project, be careful where you get your where to buy copper sheet metal or bronze bars from. Make sure it comes from a certified supplier like Rotax Metals who utilizes the latest technologies in their foundries. They sure have the highest quality products that can ensure the success of your projects.

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