How to distinguish non-ferrous metal

How to identify brass at home - Metals, equipment, instructions

For most of us, knowledge about copper and its properties is limited to a school chemistry course, which is quite enough at the everyday level.

However, sometimes there is a need to reliably determine whether a material is a pure element, an alloy, or even a composite material.

The opinion that this information is needed only by those who are engaged in the acceptance or delivery of scrap metal is erroneous: for example, on amateur radio forums, topics are often raised about how to distinguish copper in wires from copper-plated aluminum.

Briefly about element No. 29

Pure copper (Cu) is a golden-pink metal with high ductility, thermal and electrical conductivity. Chemical inertness in an ordinary non-aggressive environment is ensured by a thin oxide film, which gives the metal an intense reddish tint.

The main difference between copper and other metals is color . In fact, there are not so many colored metals: only gold, cesium and osmium are similar in appearance, and all elements included in the group of non-ferrous metals (iron, tin, lead, aluminum, zinc, magnesium and nickel) have a gray color with varying intensity of shine.

An absolute guarantee of the chemical composition of any material can be obtained only through spectral analysis. The equipment for carrying it out is very expensive, and even many expert laboratories can only dream of it. However, there are many ways to distinguish copper at home with a high degree of probability.

1. Determination by color

So, we have before us a piece of unknown material that needs to be identified as copper. The emphasis on the term “material” rather than “metal” was made specifically, since recently many composites have appeared that are very similar to metals in appearance and tactile sensations.

First of all, we consider color. It is advisable to do this in daylight or “warm” LED lighting (under “cool” LEDs, the reddish tint changes to yellow-green). It is ideal if there is a copper plate or wire for comparison - in this case, errors in color perception are practically eliminated.

Important: old copper products can be covered with an oxidized layer (a greenish-blue loose coating): in this case, the color of the metal must be looked at in a cut or saw cut.

2. Determination by magnet

Color matching is a reliable but not sufficient method of identification. The second step of independent experiments will be a test with a magnet. Chemically pure copper is classified as diamagnetic - i.e. to substances that do not respond to magnetic influence.

If the material under study is attracted to a magnet, then it is an alloy in which the content of the main substance is no more than 50%.

However, even if the sample did not react to the magnet, it is too early to rejoice, since often an aluminum base is hidden under the copper coating, which is also not magnetic (this can be eliminated by filing or cutting).

3. Determination by reaction to flame

Another way to identify copper is to heat a sample over an open fire (gas stove, lighter or regular match). When heated, copper wire will first lose its shine and then turn black-brown, covered with oxide. This method can also be used to cut off composite materials that, when heated, begin to smoke and form a gas with a pungent odor.

4. Determination through chemical experiments

The reaction with concentrated nitric acid is indicative: if the latter is dropped onto the surface of a copper product, a green-blue color will occur.

A qualitative reaction to copper is dissolution in hydrochloric acid followed by exposure to ammonia. If a copper sample is left in an HCl solution until completely or partially dissolved, and then ordinary pharmaceutical ammonia is dropped into it, the solution will turn intensely blue.

Important: working with chemicals requires precautions. Independent experiments should be carried out in a well-ventilated area using personal protective equipment (rubber gloves, apron, goggles).

How to distinguish between copper and its alloys?

Copper alloys are widely used in industry.

Over many years of research, it has been possible to obtain many materials with unique properties: high ductility, electrical conductivity, chemical resistance, strength (all depends on alloying additives).

The most common are bronze (with the addition of tin, aluminum, silicon, manganese, lead and beryllium), brass (with the addition of 10-45% zinc), as well as copper-nickel alloys (nickel silver, cupronickel, copel, manganin).

Only bronze and brass are difficult to identify, since copper-nickel alloys differ significantly in color due to their low copper content.

Copper or brass?

Brass can contain from 10 to 45% zinc, a silver-gray metal. Naturally, the more zinc, the paler the alloy. However, high-copper brasses, in which the amount of additives does not exceed 10%, differ little in color from the copper sample.

In this case, you can only trust your feelings: brass is much harder and more difficult to bend (for greater reliability, a comparison with a reference sample is advisable). You can try to remove the shavings: copper shavings will have a curl shape, brass shavings will be straight, needle-shaped.

When the samples are placed in a solution of hydrochloric acid, no reaction with copper is observed, and a white coating of zinc chloride forms on the surface of the brass.

Copper or bronze?

Like brass, bronze is much stronger, which is explained by the presence of harder metals in the alloy. The most reliable test will be a “tooth test” - there is unlikely to be a trace of pressure left on the surface of the bronze.

You can also experiment with a hot saline solution (200 g of table salt per 1 liter of water). After 10-15 minutes, a copper sample will acquire a more intense shade than a bronze one.

For those familiar with electrical engineering

Very often, copper cores from electrical cables are sold as scrap non-ferrous metals, and there are often cases when copper-coated aluminum is used in the production of electrical products. This material has a significantly lower density, but due to its irregular geometric shape, determining the volume to calculate the density is quite difficult.

In this case, copper can be determined by electrical resistance (of course, if you have the appropriate instruments - a voltmeter, ammeter, rheostat). We measure the cross-section and length of the core, take instrument readings, and Ohm’s law will help you.

Resistivity is a fairly accurate characteristic by which any metal can be identified with a high degree of reliability.

Conclusion

It is possible to accurately determine the quality of copper scrap or the content of the main substance in the alloy only after an examination: all of the above methods are approximate.

If we consider pricing when purchasing scrap metal, the most expensive is electrical copper, the cheapest are alloys of the brass group.

The final cost of the transaction can be clarified with the managers of companies involved in the purchase of scrap non-ferrous metals.

Source: https://spb-metalloobrabotka.com/kak-opredelit-latun-v-domashnih-usloviyah/

How to distinguish galvanized steel

When manufacturing metal containers or structures (for example, the widespread construction of hangars or warehouses), the quality of the metal, and, in particular, its corrosion resistance, is important. For this purpose, steels with protective (usually zinc) coatings, as well as stainless steel and aluminum are widely used. How can you distinguish between these metals and protect yourself from the actions of unscrupulous dealers?

Distinguishing aluminum from galvanization

In order to reduce the load on supporting structures, they are often made of aluminum. It is easy to distinguish aluminum from galvanized steel, especially if the buyer is not presented with a finished assembly, but with blanks made from rolled sheets or profiles. Main methods:

• By density/weight. The density of aluminum (2700 kg/m3) is almost three times less than the density of steel (76007900 kg/m3).
• In terms of surface hardness, aluminum is softer, and when scratched it will leave a deeper groove on a smooth surface.
• According to the effect on the tissue organs of the fingers. The thinnest film of aluminum dioxide upon frictional contact with wet skin of the hands will leave particles of aluminum on the surface of the fingers. When you touch them to a sheet of clean paper or cardboard, dark gray stripes will remain on it.

Externally, aluminum looks more silvery than steel, especially hot-rolled steel.

We distinguish between galvanized and non-galvanized steel

Both stainless steel and galvanized steel are characterized by good resistance to corrosion, so for short service life of structures (up to 10 years), the lower price of galvanized steel can be the decisive choice. It’s a different matter if the design is designed for a shorter period of use, and there is a reason to use ordinary steel. In such cases, it may be necessary to distinguish galvanized steel from non-galvanized steel.

A simple test will help you determine the difference between regular and galvanized steel:

• Prepare a solution of three parts table salt (not iodized!) and one part warm water.
• Dip a clean rag/cloth napkin into the solution and wipe the surface of the steel being tested with it.
• We keep the sample for 24 hours in a normal room at room temperature (you can’t leave it in the sun).
• We inspect the sample: if there are no traces of rust on it, and the surface texture is not uniform in the treated and untreated areas, then this is galvanized steel.

The basis of the test is that as a result of galvanic galvanizing - hot or cold - zinc actively penetrates deep into the base metal, introducing itself into its structure, which acquires anti-corrosion resistance. Ordinary steel does not have such a protective coating, so a saturated saline solution activates the oxidation process with the formation of light red iron oxide.

Another way to distinguish galvanized steel from non-galvanized steel is based on the different magnetic properties of the metals. Zinc, for example, is non-magnetic, so by applying a regular magnet to the unpainted surface of a workpiece, you can determine whether it contains zinc or not.

If the surface of the workpiece is already painted with heat-resistant paint, a magnet will not help. Laboratory testing is required. The greatest accuracy will be obtained by testing for electron paramagnetic resonance (EPR). EPR shows the content of material molecules on an oscilloscope, so galvanized steel will have a high zinc content on the outer surface and its presence in the inner layers. When painting, no zinc will be found in the coating.

Another method is to take a microphotograph of a ground cross-section of the sample. When galvanizing, three intermetallic layers are clearly visible in the structure, which are absent in conventional steels.

In conclusion, we will present an exotic method - you just need to lick the steel surface. Galvanized steel, unlike ordinary steel, has a chalky aftertaste, and a very distinct one.

We distinguish between galvanized and stainless steel

It is not easy to visually distinguish stainless steel from galvanized steel, since the difference in density is hardly noticeable (as is the appearance of the metal). The following types of tests must be used:

• For mechanical strength in the original state. Most grades of stainless steel have a tensile strength of at least 450 MPa. For galvanizing, this figure is much lower - up to 300350 MPa.
• For hardness according to Brinell HB. For stainless steel, NV 230300 is considered normal, for galvanized steel – NV 200250.
• For plasticity. The specific force at which cracks appear on the workpiece is 170230 MPa for galvanized steel, and 350400 MPa for stainless steel.

If mechanical tests are not enough, chemical tests are carried out using hydrochloric acid. The method is based on the properties of zinc, which, when interacting with a galvanized sheet coating, actively releases hydrogen. A small drop of hydrochloric acid is enough for the galvanized surface to begin to bubble, and the zinc layer gradually disappears. The surface of stainless steel is chemically inactive.

Electromagnetic differences between galvanized and stainless steel can also be used for evaluation. If a magnet is attracted to the workpiece, then with a high degree of certainty we can say that it is galvanized steel, while most stainless steels are non-magnetic.

Source: http://www.hugebuilding.ru/otlichiya-ocinkovki.html

7 Ways to Tell Copper from Brass

27.09.2017 17:15

To accurately distinguish brass from copper at home, it is enough to know the composition and some characteristics of these materials.

Copper is a pure metal, and its alloy with zinc is called brass. Due to their different compositions, these materials have several important differences:

• Color . Copper has a reddish tint, while brass is yellow.
• Weight . Copper is slightly heavier than brass.
• Hardness _ Copper is softer, brass is harder.
• Density _ For copper it is 8920 kg/m3, for brass it is from 8300 to 8700 kg/m3.

It should be noted right away that it is not possible to recognize at home that what we have in front of us is a metal or its alloy using a magnet. Both materials are not attracted to them.

However, there are several ways to distinguish copper from brass without resorting to spectral analysis in the laboratory. All of them are described below - from the simplest to the most complex.

1. Contact a specialist

The easiest way to identify metal is to show it to a specialist with a trained eye. This task can be easily handled by a person working in metallurgy - a foundry worker, and so on. The difference between copper and brass can also be determined by a jeweler, a pawnshop worker, a chemistry teacher, or an experienced scrap metal acceptor.

2. Determination by color

The easiest way to determine whether a product is copper or brass is by its color. For accuracy, it is recommended to thoroughly clean the metal surface from dirt and oxide film. As mentioned earlier, copper has a reddish tint, sometimes brownish or pink.

If the product under study has a yellowish color, reminiscent of gold, then this is most likely brass. And the more pronounced the yellowness, the greater the proportion of zinc in the alloy.

You can determine the metal by color by comparison with a known product. In everyday life, as a copper sample, you can use an electrical wire, cleared of insulation and protective varnish. Brass can be seen on the plugs of electrical appliances - their pins are made from this alloy.

3. Identification by sound

This method is only suitable for large items. If you hit a copper product with any metal tool, you will hear a muffled low-frequency sound. When performing similar actions with a brass object, the sound turns out to be more ringing and high-frequency.

This feature occurs because copper is slightly denser and heavier than its alloy with zinc. The described method is not suitable for small objects.

4. Determination by hardness

If the product is thin-walled, then the composition can sometimes be determined by its compliance with mechanical loads. So, copper bends much easier, but it does not crack or break. Brass is a harder and more brittle material, so a product made from it is easier to break.

This method is not suitable for thick-walled or monolithic products, since they cannot be bent.

5. Determination using chemistry

This method is one of the simplest and most accessible, and at the same time quite accurate. To determine the composition of the metal, you will need a solution of hydrochloric acid. Such liquids are often used to clean contacts when soldering in radio electronics. Accordingly, acid can be bought at any radio store. And it's inexpensive.

Without going into details and without resorting to chemical formulas, the essence of the test is as follows. A few drops of acid must be applied to the surface of the metal being tested. If it is copper, then it will simply be cleaned and acquire its natural reddish or pinkish tint. If we have brass in front of us, then a chemical reaction will take place on its surface with the release of a white substance - zinc oxide.

6. Determination by drilling

If the product is scrapped, that is, it would not be a pity to damage it, then its composition can be determined using an ordinary drill and a thin metal drill. When processing copper, due to its softness and ductility, long curling chips will come out from under the drill.

In the case of drilling brass, you will see how the metal crumbles and the chips have sharp corners. Its length, however, will be small.

7. Determination by density

This is the most complex method described, and rarely anyone adopts it. However, it is quite effective and accurate, and most importantly, it can be performed at home.

The bottom line is that first the exact mass of the product under study is determined, and then its volume. Knowing the density of copper and brass, using the identified parameters it will be possible to determine the composition of the material. If an object has a complex shape, then its volume can be calculated by immersing it in a container of water. To determine weight, it is better to use scales with high accuracy.

Source: https://metallomcity.ru/stati-o-metallolome/otlichit-med-ot-latuni

How to distinguish copper from other metals at home

One of the main problems for those wishing to sell non-ferrous metal scrap is determining its type. In this article we will tell you how to distinguish copper from other non-ferrous metals at home . Copper is one of the oldest metals discovered by man. Due to its properties, it is widely used in a variety of fields, but is most widespread in electrical engineering.

Copper is mined in both nuggets and ore. When it comes to waste and scrap, copper alloys are often found. There are several ways to tell whether a metal is pure or an alloy. Let's look at each one separately.

Check color

Almost everyone knows the copper shade, but it's worth using a wire to test. It is made without impurities, which allows you to compare colors. It is better to do this in daylight or under warm artificial light. When viewed under a cool bluish color, the tint of copper will be yellow-green.

Please note that old metal oxidizes. There will be a greenish-bluish layer on top. In this case, it is better to check the color on the cut.

Test with a magnet

Copper does not have magnetic properties. If a metal reacts to a magnet, then it is an alloy. The only point: aluminum may be hidden under the copper layer. It also does not respond to magnets. Therefore, it is recommended that after the magnetism test, you make sure that the metal on the cut is clean.

Apply Heat

If you heat a copper plate or wire, the pure sample will first fade and then turn black-brown. It should not smoke or emit strong odors. If the reaction is different, you have an alloy on your hands.

How to distinguish copper from brass or bronze

Brass alloys vary in zinc content. If there is a lot of it (up to 45%), the metal will be much whiter, and it can be easily distinguished by color from copper wire. If the zinc content is no more than 10%, it will be more difficult to determine the composition. The first option is to check for bending. The plate will be harder than pure copper. But a more reliable way is to remove the chips. At the shallows it is in the shape of a curl. Brass has needle-like straight strips.

Copper plates are usually distinguished from bronze by pressing. Soft copper leaves marks. Not on bronze.

These are the main ways to distinguish copper from other non-ferrous metals at home . For an expert assessment and detailed advice on all types of color and ferrous metal, please call the numbers listed on our website.

Source: http://stavmet.com/kak-otlichit-med-ot-drugih-metallov-v-domashnih-usloviyah

Comparison of aluminum and zinc: how to distinguish the 2 metals

It is easy to distinguish aluminum from other metals due to its lightness. The metal is widely used and is in demand in the industrial and food industries. It is not difficult to distinguish zinc from aluminum on your own. To do this, it is enough to have the necessary knowledge and techniques. We invite you to familiarize yourself with them in more detail.

How to distinguish zinc from aluminum?

Alternative options to answer the question of how to distinguish zinc from aluminum, available at home, are the following.

1. Recognition by physical and chemical characteristics

Minimum school knowledge is sufficient to determine the composition and variety of an element. Aluminum has a silver tint, is light weight, and flexible. Zinc has a bluish tint, is heavier than the previous material, and does not bend under normal conditions. Fragile, breaks quickly.

1. Determination by density parameters

To determine the type of metal by density, you will need a measuring cylinder and water. The essence of the technique is to gradually immerse the product in liquid. When a body is immersed in water, a certain amount of liquid is released. Using the simplest physical formula allows you to calculate the density of the material. The rest is left to the tabular data. If the resulting figure is close to 2.7/ml, then you have 100% aluminum.

1. Metal detection by magnet

Many elements are attracted by a magnet. However, this property does not apply to Al. Therefore, to determine the quality characteristics, it is enough to bring a magnet to the product. If the metal does not react in any way, and it has a silvery tint, then this means aluminum.

The only negative aspect of the technique is the impossibility of isolating the alloy. If it contains a large amount of aluminum, the magnet will also have no effect on it. Therefore, additional methods will have to be used to determine the purity of the alloy.

1. Thermal conductivity testing

The thermal conductivity parameters of aluminum are much higher than those of other elements of the periodic table. Therefore, the same volume of liquid under the same conditions in an aluminum pan is brought to a boil much faster. The maximum melting point of Al is 660 degrees.

1. Recognition of aluminum by chemical methods

Al is easy to determine. It is enough to apply alkali to a previously cleaned surface. After some time, the surface will oxidize, which can be seen visually.

A similar reaction occurs when metal is exposed to acid, including lemon juice. The aggressive effects of acid are manifested by the appearance of dark gray spots that disturb the appearance of the product.

The difference between aluminum and alloys based on them

To find the differences between aluminum and aluminum-based alloys, laboratory research will be required. However, the Kulibins have found several methods that they can use themselves at home.

When there is a mechanical impact on duralumin, the alloy does not produce high frequency ringing. A blow to Al provokes the appearance of ringing frequencies and has a special shine, thanks to which you can see your own reflection.

The second way to determine the presence of additional elements in aluminum is to test it with hydrogen peroxide. When a few drops of hydrogen peroxide are applied to the surface layer, the alloy will begin to change color towards darkening, which cannot be said about aluminum.

The composition of the product can be more accurately determined through examination by professional experts.

How to distinguish stainless steel from other metals

Stainless steel is widely used in the production of products and equipment, the construction industry and many other industries. Consumers often wonder how to distinguish stainless steel from other metals, because at first glance they are very similar. To solve this problem, there are some expert tips that will help you understand exactly what kind of metal was used.

How to distinguish stainless steel from aluminum

One of the most popular types of metal in production is aluminum. It is often used to make household products. To determine exactly what kind of metal you have, use these tips and perform a few simple tests.

1. The easiest way is to use a magnet. Aluminum is paramagnetic and practically non-magnetic. Even a child can carry out a test using a magnet at home.
2. Using a plain piece of paper. To carry out the test, you will need to remove dirt from the surface of the object being tested and run it with paper, pressing firmly on the product. If you have stainless steel in front of you, then there will be no traces left on the sheet, but with aluminum, gray stripes will appear.
3. Another criterion for distinguishing stainless steel from aluminum is the color of the metal. If the surface is smooth and shiny, then this is stainless steel; aluminum has a matte surface without a characteristic shine.
4. Thermal conductivity indicators. To install metal accessories, simply pour water into a container and bring to a boil. In aluminum cookware, water will boil much faster, since the thermal conductivity of this metal is much higher.
5. Separately, we can distinguish chemical methods for determining stainless steel using various acids and alkalis. When treating aluminum with alkali, brown spots remain on the surface; stainless steel will not have any visible changes.
6. Exposure to copper sulfate. You can find this reagent in any agricultural store. After application to the aluminum surface, cloudy stains will certainly remain. Vitriol has no effect on stainless steel.

Using these methods will allow you to determine at home with 100% accuracy where the product is made of aluminum and where it is made of stainless steel.

How to distinguish stainless steel from other types of steel

In appearance, all steel grades are almost identical, but at the same time they have different technical characteristics. This means that products made from different types of steel behave differently. To distinguish stainless steel from another grade of steel, you can use several methods:

• Use of nitric acid. This chemical liquid helps distinguish stainless steel from carbon steel. If you apply a few drops to the surface of the steel, a reaction will begin in which caustic steam will be released. This reaction is typical for carbon steel; no changes will occur with stainless steel.
• Check the reflection on the surface. Stainless steel has bluish-yellow tints on its surface.
• Marking. Steel products are always marked with the type and grade of material used. If the numbers are preceded by the letters “STAINLESS”, this means the use of alloy steel.

These simple tips will help you accurately determine the presence of stainless steel.

How to distinguish stainless steel from non-ferrous metals

It is difficult for an ignorant person to separate stainless steel from non-ferrous metals. This will require complex chemical actions and reagents. Still, you can use some expert advice:

1. Take a small piece of the sample and drill a hole. In duralumin, the chips move away in a spiral and do not stick to the drill.
2. Hydrogen peroxide and 20% sodium sulfide can be used. When these reagents are applied to a cut, the surface of non-ferrous metals will darken.

Distinctive characteristics of food grade stainless steel from technical grade

It must be said that the division of stainless steel into two types has a special character, since they differ in areas of use. The main difference between them is the surface treatment. For the food type, the surface is of particular importance, since the metal will come into contact with food products.

Distinctive features of food grade stainless steel are a smooth surface with a high level of processing. Food grade stainless steel is a highly alloyed metal that is resistant to corrosion and rust. The amount of additives affects the quality of product operation. The food grade is susceptible to the influence of an aggressive alkaline environment, so it adds more metal impurities. Based on the composition and markings, you can accurately determine what type of stainless steel it is.

Results

To determine the type of metal and the distinctive features of stainless steel, it is enough to know the basics of chemistry and some characteristics of metals. By conducting simple chemical experiments or using simple household methods for installing stainless steel products, you can easily determine what type of metal was used.

We also recommend reading:

Why paint aluminum structures?

Anodized aluminum - what is this technique?

Do you want to ensure the durability of your construction? Choose an aluminum profile!

Source: https://aluminiypro.ru/kak-otlichit-nerzhavejku-ot-drugih-metallov

How to determine what metal a product is made of - Metalist's Handbook

How to determine a metal and its origin? The question is mainly of interest to jewelry owners who are afraid of purchasing a fake for an impressive amount. You can deal with this problem yourself or contact an expert. The jeweler will conduct an examination, issue an opinion and charge a fee for the work. Authenticity testing can cost from 10 to 20% of the cost of jewelry. If you can’t contact a specialist, then you should try to solve the problem on your own.

Comparison of platinum, silver and white gold

How to check?

Owners of platinum jewelry should remember:

1. Platinum is an expensive and heavy metal, and small jewelry is often made from it.
2. Platinum can be replaced with silver, but such a substitution can be recognized by color.
3. The hardest thing to distinguish from the original is jewelry that has a layer of platinum applied to it.
4. The mark on the surface of the product should not raise doubts.
5. Platinum is not afraid of high temperatures and reagents.

The cost of platinum is constantly increasing; there is not much of this metal in the world. Therefore, if in a store a buyer is offered to purchase an impressively sized product made of platinum, and its cost is quite low, he should refuse the purchase. Platinum is not sold cheaply, and jewelry made from it is small; the metal is too heavy.

Platinum Bank Bar

Silver and platinum are similar in appearance, so the expensive metal is often replaced with silver. Such a fake will give itself away with a black tint and plasticity. Silver is not resistant to damage; a mark will remain on its surface, but it will not be possible to spoil a platinum product in this way.

If a layer of platinum is applied to the surface of the product, then a fake can be recognized by its weight. When this is not possible, it will not be possible to determine its quality without causing damage to the jewelry.

Before purchasing, you need to carefully examine the mark; you can use a magnifying glass for this. If all the numbers are clearly visible, most likely the jewelry is really made of platinum.

Due to its chemical properties, platinum is not afraid of high temperatures and acids. When immersed in acid, ammonia and even when exposed to iodine, the product will not change. If you try to heat a ring or earring with a lighter, the temperature of the jewelry will not change immediately. Platinum is a poor conductor of heat, unlike silver.

Gold and silver

At home, gold and silver are most often tested. You can also buy a fake in a jewelry store, but don’t panic.

It is easy to check the authenticity of silver; just immerse it in hot water. The metal will immediately heat up, but will not hold the temperature for long.

Gold jewelry

If you apply a small amount of sulfur ointment to the surface of silver jewelry, the product will immediately darken. This will indicate the authenticity of the metal.

Low-grade silver is easier to distinguish; you just need to hold the item in your hands and then examine your palms. If there are black marks or stains on them, the quality of the silver leaves much to be desired.

Iodine is a universal tool for testing precious metals; a drop of it can resolve all issues. If after the procedure there are streaks left on the surface of the jewelry, it is a fake.

Gold is also tested using iodine. If after the test the metal changes color, absorbs iodine and a stain forms on its surface, this is a sign of a fake or an alloy that contains a large number of other non-precious metals.

Checking gold with a magnet

Gold can also be identified by color: if the jewelry has a red tint, then it probably contains copper. The latter changes color at high humidity and acquires a green tint. Therefore, if gold changes color when in contact with water, it contains copper in large quantities. An exception is red gold, which gets its color by adding copper to the alloy.

A clean piece of paper will help distinguish fake from gold. It is enough to sweep two decorations across its surface at the same time. If the stripes do not have any differences, then they are made of gold.

Only gold that is 585 or higher should be checked for authenticity; other products will not pass the test. And the use of chemical elements during the procedure can ruin the jewelry.

It is difficult to distinguish gilding from gold; for this you can make a notch. The damage will allow us to study the metal at the cut site. If there are no differences, then the jewelry is made of gold.

Another universal method for checking jewelry is a magnet. Noble metals do not react to magnets. If the product behaves differently, then it contains iron or steel.

Some craftsmen have learned to distinguish silver from base metals by assessing the smell - this test is very dubious.

None of the above methods will give a 100% guarantee. You may suspect a fake, but only an expert can accurately determine the quality of the metal. Some silver items are not assayed at all. This is a reason to think, but such a phenomenon does not indicate that it is a fake. You can understand the authenticity of the metal and its quality after some time. If, a few days after purchase, the earrings, ring or bracelet darken, this should be regarded as the first sign of a fake.

Source: https://ssk2121.com/kak-opredelit-iz-kakogo-metalla-izdelie/

Learning to identify copper and distinguish it from other metals and alloys

Chemically pure copper has three distinctive characteristics. It is a colourful, ductile and corrosion resistant metal. The latter property is due to the formation of a thin oxide film. This layer makes the copper chemically inert in a non-corrosive environment and also adds a red tint to its golden pink color.

The best way to accurately identify copper is spectral analysis, which requires expensive equipment - a metal analyzer, while identifying copper at home is a task with a limited set of tools.

Here the best instruments are the senses, easily accessible chemicals, fire and improvised devices.

How to distinguish copper from other metals by eye?

Visual perception is the simplest, but not always quite accurate method. However, in most cases it works and it is not difficult to distinguish copper scrap from other non-ferrous metal scrap. Indeed, despite the name of the category non-ferrous metals, only the following are equally colored:

• copper;
• gold;
• cesium;
• osmium.

The remaining metals are characterized by a gray tonality and differ mainly in the intensity of their shine. Therefore, color is an excellent “means of identification” in such matters as distinguishing copper from aluminum, zinc or nickel.

The natural color of the pure element Cu is red-pink. It is recommended to look at metal in natural light. Artificial lighting, with the exception of LED lamps with warm color temperatures, changes the hue towards a yellow-green tone.

The second rule for visual identification of copper is that the surface oxide film must be removed. Oxidation creates a greenish-blue coating on the metal surface. Therefore, to determine by color that you have copper, preferably by fresh sawing or by processing the material with a file. The situation with copper alloys: brass and bronze is much more complicated. It is also visually difficult to distinguish between Cu and copper-plated aluminum.

How to distinguish copper from brass and bronze

The first metal is a Cu-Zn alloy. zinc varies in the range of 4 – 45%. When an alloy is characterized by a high addition of a major impurity, it is easy to distinguish it from pure metal by color. The color of copper is pink-red, brass is lighter, but scrap brass may have a dirty surface.

The more zinc in the alloy, the more its color shifts from red to yellow. Therefore, visual perception is unacceptable for high-copper brasses, where the presence of impurities is at the level of 10%.

In this case, there are 3 options left for how to distinguish copper from brass without using a tool:

1. By sound. It is advisable to have an ear for music here. When struck against metal, soft copper sounds muffled, while brass sounds loud. The method works well for massive, oversized products - pipes, for example.
2. Along the fold. The ductility of copper allows the metal to be easily bent. Harder brass is not as malleable.
3. By weight. The density of Cu 9 g/cc is higher than that of Zn (7.1). The resulting characteristic value for brass is on average 8.6 g/cc. The difference is small, but if you have accurate scales, it is possible to distinguish metals.

A good identifier of copper, relative to brass, is shavings. In pure metal it is spiral-shaped. On the contrary, the brass shavings are straight and needle-shaped.

A more complex approach involves the use of chemicals, namely hydrochloric acid. Chemically inert copper does not react in solution, whereas when brass is immersed, a white coating forms on the surface of the metal. This is zinc chloride, the result of the reaction of this metal with an acid.

copper and brass:

It is not always possible to determine which metal is in front of you by color. Bronze is an alloy of copper and tin, also characterized by a pink-red hue; scrap bronze can be found in anything. In this case, the main distinguishing characteristic is the ductility of the pure metal. By pressing on the copper with a hard object, we get a notch on the surface. Deforming bronze is much more difficult.

An alternative way to distinguish copper from bronze at home is a saline solution. Add 200 grams of table salt to a metal container containing 1 liter of water. The solution is heated to a temperature above 50 °C. Next, the metal is placed in the heated liquid and kept for about 15 minutes. The color of copper changes. Bronze remains insensitive to the effects of saline solution.

The next method is patination of copper. Oxidation of pure metal over time in air is an inevitable process, leading to the formation of a greenish-blue coating. Bronze is not subject to patination.

How to distinguish copper from aluminum

Naturally, metals are easy to distinguish by color. The situation becomes more complicated when it is necessary to determine what the cable cores are made of. Tinned copper takes on a silvery tint, while copper-plated aluminum takes on a yellow tint. The result is that it is extremely difficult to distinguish metals from each other by color.

The best option is to measure the resistance. For a copper twisted pair cable about 100 meters long, the parameter value reaches 4–8 ohms. The resistance of a similar aluminum cable is significantly higher: 12 – 20 Ohms. This method is good because there is no mechanical impact on the metal.

The second method is bending/extension of the vein. The aluminum conductor will break quickly. The next option is a flame test. The melting point of aluminum is 600 °C, that of copper is much higher.

Other cases of fire and acid testing

Exposure to flame is used not only to identify metal relative to aluminum. For these purposes, a gas stove, lighter or fire is sufficient. Heating copper leads to the formation of its oxide, which affects the color change. The surface of the metal gradually becomes dull until it acquires a completely dark shade.

Nitric acid is another identifier for copper at home. It is also important to be careful here. It's better to just drip the liquid onto the metal. Pure copper at the point of contact will turn blue-green.

from here

Source: https://tsvetmet.wordpress.com/2018/09/10/%D1%83%D1%87%D0%B8%D0%BC%D1%81%D1%8F-%D0%BE%D0% BF%D1%80%D0%B5%D0%B4%D0%B5%D0%BB%D1%8F%D1%82%D1%8C-%D0%BC%D0%B5%D0%B4%D1%8C -%D0%B8-%D0%BE%D1%82%D0%BB%D0%B8%D1%87%D0%B0%D1%82%D1%8C-%D0%B5%D0%B5-%D0 %BE/amp/

Copper: color, mining features, characteristics of the metal

Copper in its pure form is characterized by plasticity, viscosity, and can be easily rolled into thin metal sheets. It has been mastered by man and has found wide application since ancient times, thanks to a relatively affordable method of extraction from ore at a low melting point. Most people know what color copper is. It is a reddish metal, brown in some areas, and with a pink tint at the fracture.

Metal mining

In nature, copper in the form of nuggets is more common than gold, silver or iron. The oldest copper objects, as well as slag, indicating its smelting from ore, were discovered in Turkey during excavations of ancient settlements.

It is known from history that the Stone Age was followed by the Copper Age, characterized by the manufacture and use of copper objects.

Research by scientists suggests that even with the softness of the metal, tools made of copper are superior to stone products in the speed of planing, chopping, drilling and sawing wood.

Copper ores are mineral deposits that contain not only copper, but also other substances that contribute to their properties, such as nickel. Copper ores are considered to be those types of ores in which the copper content would be sufficient for reasonable extraction by industrial methods. These requirements are met by ores containing non-ferrous metal in the range from 0.5 to 1%. The Earth has copper-bearing resources, 90% of which are copper-nickel ores.

Ore is now mined in a number of countries, but the largest deposits are found in Australia, Chile, Indonesia, and the USA. In recent years, the continuous process of mining this metal has noticeably decreased. This is due to the widespread use of scrap (raw materials) in industry.

Due to the strength of the metal and the ability to retain its physical and chemical properties for a long time, the life cycle of copper is quite long, although products become unusable over time.

They are handed over to metal collection points, and a new process of processing copper scrap begins, consisting of several stages and having a positive effect on the economics of production.

At the same time, the bowels of the earth remain untouched; moreover, processing ore requires considerable energy expenditure, and 90% less is spent on processing scrap. Not all metals are characterized by such a high indicator.

Copper belongs to the group of non-ferrous metals, even the ore has a distinct copper color. Ore is mined mainly by open-pit mining, that is, without mine structures, and the metal is extracted using beneficiation using the flotation method.

The ore rock is wetted with water, non-metallic substances are moistened and stick together, forming waste, and non-wetted particles rise up and form foam.

Then the copper ore undergoes an additional purification cycle, is sent to the smelting furnace, and then to the production of blanks.

Characteristics and features

Copper appears as a golden-pink metal, which when exposed to air acquires an oxide coating of a yellowish-red hue. Just like gold, cesium and osmium, it is characterized by individual coloration. There are some other features of the metal:

1. It has a high degree of electrical conductivity (in second place after silver), especially when used in its pure form. The admixture of other metals or any substances in the composition reduces its conductivity.
2. The metal is strong and durable, therefore it is widely used in the production of pipes and roofing materials.
3. The attractive color and shine of copper made it possible to use it for making dishes, various decorative items, objects and interior decorations.
4. An important feature of copper is the oxidation process. When interacting with a humid environment, the metal acquires a unique coating. Thanks to the patina layer, the metal is protected from corrosion and various damages. This property of copper is often used by artists and sculptors. By artificially exposing the metal to moisture, an unusual color of the product is obtained. An example is the Statue of Liberty in the USA. Over the years, a patina began to form on it, and the monument acquired a green tint. Now Americans call their symbol “Green Lady.”
5. It is highly energy efficient. The good thermal conductivity of the metal allows for significant energy savings. If the heating system is equipped with insulated copper pipes, heat loss is reduced many times. Conversely, in cooling systems, the metal maintains the set temperature.
6. This is an essential trace element involved in many processes of the human body: hematopoiesis, sugar and cholesterol metabolism, promotes the absorption of iron, improves the functioning of the cardiovascular system and brain.

Many foods are rich in this metal. The daily dose required for the normal functioning of the body is from 1.5 to 3 mg per day. It must be borne in mind that an insufficient amount has a detrimental effect on the human body.

Difference from other elements

Chemically pure metal is characterized by three features - an individual color (as copper is found in everyday life), ductility and resistance to corrosion. The latter property is formed due to the formation of a thin oxide film. This layer complements the dark red tint of pink copper, and also gives the metal chemical inertness in a non-aggressive environment.

To identify copper, spectral analysis is used, which requires a special expensive device - a metal analyzer, while self-analysis will require a set of certain techniques:

1. Visual difference between copper scrap and other non-ferrous metals. In natural light, pure Cu element has a red-pink color. Artificial lighting changes the color of copper, sometimes closer to a yellow-green tone.
2. Removal of surface oxide film. To do this, you need to break the top layer with a file.

It will be more difficult to distinguish a pure element from copper alloys: brass and bronze, as well as copper-coated aluminum. Brass contains copper and zinc, the presence of which ranges from 4 to 45%. With a high percentage of impurity content, it will not be difficult to distinguish from pure metal, since the color of the brass will be lighter.

As the amount of zinc in the alloy increases, a shift occurs from red to yellow. Therefore, high-copper brass with 10% impurity content can be visually mistaken for pure copper. However, there are three options that can make the difference:

1. Identification by sound. When hitting metal, soft copper will produce a muffled sound, while brass will produce a ringing sound. This method works effectively for large-sized products, such as pipes.
2. Along the fold. It can be bent easily, whereas stiffer brass is less flexible.
3. By weight. Density of Cu 9 g/cu.m. cm. This is higher than that of zinc (7.1). Brass is characterized by an average value of 8.6 g / cubic meter. cm.

Copper can also be identified by metal shavings: copper has a spiral shape, brass is straight, needle-shaped. You can use chemicals such as hydrochloric acid. The copper will not react while in solution, and the surface of the brass will become coated with a white coating called zinc chloride as a result of the reaction.

Methods for determining bronze and aluminum

It is not always possible to determine the type of metal by color. For example, bronze is an alloy of copper and tin and also has a rose-red hue. Therefore, you need to use the plasticity testing method. When pressing on copper with a hard object, a notch will remain on the surface; bronze will not be deformed during such manipulation.

You can distinguish copper from bronze using a salt solution. Dissolve 200 g of salt in one liter of water, pour into a metal container and heat to 60 degrees. Then place the pieces of metal into the hot liquid and wait about 20 minutes. Copper will change color, but bronze will not react to the salt solution.

Metals can also be identified by the patination properties of copper, which after a certain time oxidizes and becomes covered with a greenish-blue coating. Bronze does not have this property. Metals are easy to distinguish by color. It is more difficult to determine what the cable cores are made of. Tinned copper has a silvery tint, and copper-plated aluminum is light yellow, so it is very difficult to distinguish them by color.

The correct way would be to compare their resistance. A twisted pair of copper conductors, 100 m long, has a parameter value from 4 to 8 Ohms, the resistance of an aluminum cable of the same length is much higher (from 12 to 20 Ohms). Knowing that copper has a high degree of electrical conductivity, we can draw conclusions. The veins are also checked using bending and extension. An aluminum conductor will quickly break, but a copper conductor will take some time.

Roofing coverings

The original color inherent in copper, as well as its anti-corrosion properties, played a big role in its development as a roofing material many years ago. For a long time, cheaper steel and aluminum were used in this capacity, but recently designers and architects have again become interested in the unusual metal.

Copper roofing is distinguished not only by its luxury and attractiveness, but also by its high quality and long service life, its ability to withstand various influences: mechanical, temperature and others. Houses with copper roofing have a stylish and presentable appearance.

Thanks to technological capabilities, it is now possible to immediately obtain copper of the desired color ; previously, houses were covered with shiny yellow scrap metal. Over time, the color of the roof gradually darkened as metal oxide formed on its surface.

And over time, chemical processes that occurred under the influence of the environment formed a layer of malachite-green patina on the roof.

Thanks to this layer, the metal is reliably protected from the corrosion process, so roofs covered with patina last for several decades and at the same time retain their performance characteristics.

Currently, specialized stores are equipped with many catalogs where you can immediately select copper sheets of a suitable color to cover the roof. Thanks to modern technologies, you can choose between classic, oxidized and patinated coating types.

Nowadays copper is used not only for the roofs of houses, but also for facades. This is both beautiful and profitable. The copper facade does not require special care, does not fade in the sun, and protects the building from temperature changes and high humidity.

The originality of the color is distinguished by copper oxide and sulfate, which are widely used in industry. Copper oxide, which has black crystals, is used to tint glass and paint materials. Copper sulfate is not used as a dye, but it has a wonderful blue-turquoise color.

Source: https://othodynet.ru/othody/med-tsvet-osobennosti-dobychi-harakteristika-metalla

How to determine what we have in front of us: brass or copper, their main differences

Anyone who searches for and sells non-ferrous metal sometimes has doubts about the type of scrap and, accordingly, its true value upon delivery.

Copper is a non-ferrous metal, and brass is an alloy that is typically 70% copper, so it often resembles it.

A mistake can be quite costly. For copper at collection points they give 285-300 rubles, for brass - about 150 . There are many ways to find out what kind of metal we see - copper or brass, and we will tell you how to distinguish them from each other in this article.

What is copper and brass

Copper is a non-ferrous metal. Its color is reddish-pink, it is pliable when working, soft and malleable. It has high thermal and electrical conductivity, so copper is often used to produce:

• parts of electrical appliances;
• cables;
• radiators.

Copper is not hardened because it becomes hard even after cold forging. It tends to become covered with patina - a green coating that occurs when the ambient humidity is high.

To increase strength, improve a number of other indicators and reduce the cost of the material, impurities are added and an alloy is obtained.

One such alloy is brass .

In the classic version it contains a third of zinc.

Brass is golden yellow, stronger and harder. It does not oxidize so intensively , and is not so plastic.

Sometimes, depending on the purpose of the alloy, they add:

• tin;
• silicon;
• lead;
• manganese.

Similarities and differences

Brass alloy consists mostly of copper, so it is natural that they are similar not only visually, but also in some properties. The more copper in the alloy, the more similar their colors will be. This is where the exact coincidences end.

Visually, less than 80% copper are easily distinguished . They are slightly similar to gold, as they have a pronounced yellow tint. The more zinc, the lighter the shade.

Because of this, brass is even used to counterfeit or imitate gold . Copper has a main shade of reddish, which often has a pink tint.

With a strong decrease in temperature, brass does not lose its relatively limited ductility and does not become brittle . Conducts electricity and heat worse.

They differ in such a way as hardness .

Copper is softer and more ductile , while brass, on the contrary, is hard and it is difficult to give it any shape without annealing.

The shavings are also different: for brass they are needle- shaped , for copper they are twisted into a spiral .

Let's look at the properties that brass and copper have and whether they have any differences:

Copper	Brass
Plastic, soft	Solid
Reddish-brown-pink tint	Golden tone
Lower sound on impact	Alt
Heavy	Easier
The shavings are twisted into a spiral	Needle shavings

Most often you can distinguish by:

• mind;
• weight;
• degree of hardness

without the use of any tools or equipment.

But there are situations when, for accuracy, it is necessary to use :

• reagents,
• tools,
• devices.

Before assessing the scrap that you are going to take to the collection point, you need to clean it of dirt, otherwise you won’t be able to accurately determine it by eye.

Both metals, although to varying degrees, can develop a patina .

Therefore, do not forget to clean the scrap well.

If an object has been in the open air or in water for a long time, the patina layer is difficult to remove.

Sometimes it will be justified to purchase a special cleaning product .

It is advisable to inspect the scrap under a powerful white light.

This implies that one can view either under the sun on a fine day or under a bright fluorescent lamp . Incandescent lamp is not suitable.

Pure copper will have a reddish-brown tint, sometimes with a pink tint. Keep in mind that brass can be red or orange. This type is commonly used for decorations and water pipes.

If the material has an orange, yellow or golden tint, you can be almost sure that it is brass.

Source: https://rcycle.net/metally/cvetnye/kak-opredelit-latun-ili-med-ih-osnovnye-otlichiya

Which is harder, aluminum or brass?

Business July 24, 2018

We welcome everyone who, being a real owner, draws knowledge and experience from our site. This suggests that today for some reason you are interested in the question of how to distinguish aluminum from stainless steel. But really, it’s not that simple.

Features of aluminum

Why is aluminum so valuable? This is a pure metal classified as non-ferrous. It is lightweight, durable, has a good degree of deformation, and is resistant to aggressive environments and corrosion.

All of the listed advantages allow it to be used in a variety of areas from industry and construction (except for industries where high-strength structures are manufactured) to domestic use.

The demand for the valuable metal is great, so it is important to know how to accurately distinguish it from other similar metal alloys.

Aluminum or stainless steel: methods of determination

There are several ways to help you do simple research on your own at home. Find out how to distinguish aluminum from stainless steel - advice from forum members and experts.

1. Using a magnet. Aluminum of any grade will not stick to a magnet. Stainless steel also has this property. But there is an exception to the rule. If it contains nickel in sufficient quantities, the tested products will have some attraction. If there is a lot of chromium or copper in a stainless metal, it will not have any effect on the magnet.
2. Marking on stainless steel. Some stainless steel products have identification markings. This already gives a hint on how to distinguish aluminum from stainless steel. If there are markings, for example, “STAINLESS” and the like, this is not aluminum.
3. Plain paper won't lie. The method is very simple. Experiment conditions: you need white, as thick paper as possible (printer paper will also work). Use a thick cloth to remove dirt from the edges of the products being tested. Move the cleaned areas one by one with some pressure across the sheet. There will be no traces left of the stainless steel. Aluminum will draw gray stripes.
4. How to distinguish aluminum from stainless steel by the color of the metal? The surface of the object has a shiny, colorless hue that does not change over time - it is stainless steel. The matte surface of a product that has a grayish or whitish color is aluminum. It will not be polished with sandpaper to a high gloss finish. Check it out.
5. Under mechanical load. Another simple way will help you understand how to distinguish aluminum from stainless steel. Hit the product against the surface of any hard metal in the dark. Aluminum will never spark, unlike stainless steel.
6. Thermal conductivity, melting. Compare where the water heats up faster. Of course, in an aluminum container. This metal has much better thermal conductivity. But it is not used on the burner of a gas furnace; the melting point is 660 °C. Stainless steel cannot be melted in the usual way (melting index is above 1800 °C).
7. Testing for copper sulfate. An option available to everyone. Copper sulfate, after exposure to aluminum, will leave cloudy stains and traces on it, but will not appear on stainless steel.
8. Alkaline solutions. Any housewife knows that it is impossible to boil aluminum cookware in alkaline solutions. It will darken and lose its appearance. Conclusion: aluminum products are afraid of alkali, both sodium and potassium. The same cannot be said about stainless steel.
9. Acid test. All acids, starting with the usual citric acid and ending with more aggressive ones, will leave marks when they get on the aluminum surface. You won’t see them on stainless steel; it doesn’t react with acids.

Duralumin – an alloy of aluminum with transition metals

The industry is not able to provide itself only with pure metal, and duralumin comes to the rescue here - various combinations of manganese, copper and magnesium in an alloy with aluminum.

In addition to all the above properties of its older brother, the transition metal has:

• high degree of strength;
• long service life;
• plasticity;
• high hardness.

It accumulates fatigue properties more slowly and is resistant to cracking.

The disadvantage of products made of duralumin is susceptibility to corrosion, which can be prevented by anodizing, applying a thin layer of paints and varnishes, aluminum.

The choice between the two metals depends on the end use. We pay tribute to their advantages, but also foresee their disadvantages. The domestic sector leaves the choice to aluminum, while the industrial sector votes for the strength that duralumin has.

Naturally, the question arises of how to distinguish aluminum from duralumin. It is almost impossible to determine by eye which metal is which. The chemical laboratory will give you the exact answer. But experts on the forums have their own opinion on this matter.

1. Follow the markings.
2. The color of the alloy is steel gray.
3. Scratches leave clear marks.
4. A ringing sound is heard from the impact.
5. During processing, the chips will break without ductility.
6. The structure of the alloy is fine-crystalline.

You can determine the type of material by conducting an experiment. Apply a drop of sodium hydroxide to duralumin and aluminum samples for 10 minutes. After removing the substance, we learn about the metal from the resulting stains: the dark one is duralumin.

If you place a piece of aluminum in an acid with added alkali, it will dissolve, forming a white powdery precipitate. In the experiment with duralumin, blue copper granules will be present.

Unlike aluminum, the main characteristics of the alloy are lack of ductility, brittleness and hardness.

Everything can be learned by comparison; examine the parts of two samples several times, pick them up and compare the weight. Such familiarity will help you subsequently simply recognize metals.

Silumin - a twofold relationship

Products made from silumin, an aluminum-based alloy with the addition of silicon, literally flooded the market. Why does it attract the buyer and how to distinguish aluminum from silumin?

Advantages of silumin

Of course, this alloy of two materials has its “fans”. They call the following positive features of silumin:

• light in weight;
• highly durable;
• resistant to wear and corrosion;
• cheap price.

Cons of silumin

Silumin products should be treated with caution, unlike aluminum ones. in silumin, aluminum production waste, silumin-containing alloys, and metal powder do not have an exact proportion. It cannot be called high quality, since the manufacturer produces cheap products under the name of some brand.

The disadvantages of the alloy include:

• design flaws;
• they are unsuitable for food products;
• dangerous to health.

You can distinguish silumin from aluminum visually. The products have a glossy smooth gray surface.

Today, public dissatisfaction with plumbing products continues to grow due to the heterogeneous structure of the material with numerous internal stresses and voids. After 3-5 months, the water tap turns into dust, and the rotary steel ball rusts.

Bimetal and aluminum using radiators as an example

When replacing heating radiators, many are faced with the choice of which material to choose for the new design. Cast iron batteries are a thing of the past; manufacturers offer aluminum, steel and bimetallic ones.

While steel is easily recognizable in appearance, the problem with aluminum and bimetallic structures is that you can’t tell the difference by eye. Moreover, the latter option is in greatest demand.

In the store there is a chance not to buy a fake, but how to distinguish bimetal from aluminum at the market?

Visual recognition will not provide accurate results to the consumer. Both the aluminum and bimetallic systems have external fins made of aluminum. And it’s impossible to visually determine the weight of one section.

For reference: the aluminum section weighs 1–1.6 kg, the bimetallic radiator “compartment” weighs 1.5–2 kg.

You can use the “old-fashioned” method and arm yourself with a neodymium magnet, which has greater power.

Preliminary test. Place the magnet first on the steel, then on the aluminum radiator. The magnetic tester will attract the first option to the surface. The effect will be weaker for a bimetallic radiator. Its steel tubes are located under a diamagnetic material - aluminum. With a powerful neodymium magnet, it is possible to catch the attraction.

It is more difficult when the coolant tubes are made of copper, which, like aluminum, is impervious to the magnetic field.

  Does aluminum rust or not?

Difference from other non-ferrous metals

It is known that metals have largely identical properties. But each element has its own distinctive characteristics. They allow you to understand how to distinguish metal from aluminum:

• copper is recognized by its bright reddish hue;
• iron and its alloys have high magnetic properties;
• You can recognize gold by its yellow color;
• Lead has high fragility and density;
• silver has a bright shine;
• Tin has high ductility.

The above methods are only estimates and approximate. More reliable information is available on the pages of special reference literature.

Source: https://varimtutru.com/chto-tverzhe-alyuminiy-ili-latun/