We welcome everyone who, being a real host, 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 indeed, it is not so simple.
Features of aluminum
Why is aluminum so valued? This is pure non-ferrous metal. It is lightweight, durable, has a good degree of deformation, and is resistant to aggressive media and corrosion. All these advantages allow you to apply it in a variety of areas from industry and construction (except for industries where high-strength structures are made) to use in everyday life. The demand for valuable metal is great, therefore 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 your own simple studies at home. Learn how to distinguish aluminum from stainless steel - tips from members of the forum and experts.
- With a magnet. Aluminum of any brand will not stick to the magnet. Stainless steel also has this property. But there is an exception to the rule. If nickel is present in its composition in sufficient quantity, the test products will have some attraction. If there is a lot of chromium or copper in a stainless metal, this will not affect the magnet in any way.
- Marking on a stainless steel. Some stainless steel products have an identification mark, which already gives a hint on how to distinguish aluminum from stainless steel. In the presence of markings, for example, "NERZH" and the like, this is not aluminum.
- Plain paper does not lie. The method is very simple. Experimental conditions: you need white, as thick paper as possible (printer paper is also suitable). Remove dirt from the edge of the test piece with a thick cloth. Swipe alternately cleaned places with some pressure on the sheet. There will be no trace of stainless steel. Aluminum will draw gray streaks.
- By the color of the metal, how to distinguish aluminum from stainless steel? The surface of the subject is a brilliant colorless shade that does not change over time - this is stainless steel. The dull surface of a product that has a grayish or whitish color is aluminum. It is not polished with sandpaper to a shiny gloss. Check it out.
- Under mechanical stress. Another simple way will help you understand how to distinguish aluminum from stainless steel. Hit in the dark with the product on the surface of any hard metal. Aluminum will never sparkle, unlike stainless steel grades.
- Thermal conductivity, melting. Compare where the water heats 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. Do not melt the stainless steel in the usual way (melting point above 1800 ° C).
- Check for copper sulfate. An option available to everyone. After exposure to aluminum, copper sulfate will leave cloudy streaks and traces on it, but will not appear on stainless steel.
- Alkaline solutions. Any housewife knows that it is impossible to boil aluminum dishes in alkaline solutions. It will darken and lose its appearance. Conclusion: aluminum products are afraid of alkali, both sodium and potassium. What can not be said about stainless steel.
- Acid test. All acids, from ordinary citric to more aggressive, falling on an aluminum surface will leave traces. You will not see them on a stainless steel; it does not 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 helps out here - various combinations in the alloy with aluminum of manganese, copper and magnesium.
To all the properties of the elder brother listed above, the transition metal has:
- high degree of strength;
- long service life;
- ductility;
- high hardness.
Slower accumulates fatigue properties and is resistant to cracking.
The disadvantage of duralumin products is their susceptibility to corrosion, which can be prevented by anodizing, applying a thin layer of paints and varnishes, aluminum.
The choice between two metals depends on the end use. We give credit to their merits, but also provide for the shortcomings. The household sphere leaves the choice for aluminum, the manufacturing sector votes for the strength that duralumin has.
Naturally, the question arises of how to distinguish aluminum from duralumin. Determining by eye where a metal is is almost impossible. The exact answer will give the chemical laboratory. But experts on the forums have their own opinions on this matter.
- Navigate by labeling.
- The color of the alloy is gray-steel.
- Clear marks remain from scratches.
- A jingle is heard from the blow.
- During processing, the chips will break without viscosity.
- The alloy structure is crystalline.
You can determine the type of material by conducting an experiment. Apply a drop of caustic sodium to duralumin and aluminum samples for 10 minutes. After removing the substance from the formed spots, we learn about the metal: dark is duralumin.
If you place a piece of aluminum in acid with the addition of alkali, it will dissolve, forming a white powder precipitate. In the experiment with duralumin, blue granules of copper will be present.
Unlike aluminum, the main characteristics of the alloy are the lack of ductility, brittleness and hardness.
Everything is known in comparison, examine several times the details of two samples, pick up, comparing the weight. Such an acquaintance will subsequently help simply recognize metals.
Silumin - a twofold attitude
Products made of silumin, an alloy based on aluminum with the addition of silicon, literally flooded the market. What attracts the buyer and how to distinguish aluminum from silumin?
The benefits of silumin
Of course, this alloy of two materials has its own “fans”. They call such positive features of silumin:
- light in weight;
- high strength;
- resistant to wear and corrosion;
- cheap price.
Cons of Silumin
Silumin products should be treated with caution, unlike aluminum. Silumin content of aluminum production wastes, silumin-containing alloys, metal powder does not have an exact proportion. It can not be called quality, since the manufacturer gives out cheap products under the name of a 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. Products have a glossy smooth gray surface.
Today, the discontent of the population regarding sanitary products continues to grow due to the heterogeneous structure of the material with numerous internal tensions and voids. After 3-5 months, the water tap turns into dust, and the ball made of rotary steel rusts.
Bimetal and aluminum on the example of radiators
When replacing heating radiators, many are faced with the choice of which material of a new design to give preference to. Cast iron batteries are a thing of the past , manufacturers offer aluminum, steel and bimetallic. If steel is externally easily recognizable, then with aluminum and bimetallic structures there is a problem, you cannot tell by eye. Moreover, the latter option has the greatest demand. The store has a chance not to buy a fake, but how to distinguish bimetal from aluminum in the market?
Visual recognition will not give accurate results to the consumer. Both the aluminum and the bimetallic systems have external fins made of aluminum. Yes, and to visually find out the weight of one section is unrealistic.
For reference: the aluminum section weighs 1–1.6 kg, the “compartment” of the bimetal radiator - 1.5–2 kg.
You can use the "grandfather" method and arm yourself with a neodymium magnet, which has great power.
Preliminary test. Bring the magnet first to the steel, then to the aluminum radiator. The magnetic tester will draw to the surface of the first option. The effect of a bimetallic radiator is less pronounced. Its steel tubes are under a diamagnet - aluminum. With a powerful neodymium magnet it is possible to catch the attraction.
It is more difficult when the heat transfer tubes are made of copper, which, like aluminum, is immune to the magnetic field.
Unlike other non-ferrous metals
It is known that the properties of metals are more identical. But each element has its own distinctive characteristics. It is they that make it possible to understand how to distinguish metal from aluminum:
- copper is recognized by a bright reddish hue;
- iron and its alloys have high magnetic properties;
- You can recognize gold by yellow;
- lead has high fragility and density;
- silver is bright;
- tin has high ductility.
The above methods are only estimated and approximate. More reliable information is available on the pages of special references.