What is the melting point of tin

Melting point of tin in degrees Celsius

Tin is one of the most studied metals by man. It was discovered in prehistoric times. Already ancient man knew what the melting point of tin was, the physical and chemical properties of this metal and the range of its use in everyday life. The alloy of tin and copper is man's first attempt at metallurgy, the first artificial metal compound created by human hands.

Tin in nature

The most important natural compounds are cassiterite, which includes tin oxide, and stannin (tin pyrite). In ancient times, this metal was mined in open mines, but in the modern world there are practically no open deposits of tin left. On an industrial scale, it is smelted from ores containing about 1% of this substance. Thus, to obtain 1 kg of pure tin, you need to process a hundredweight of ore.

Uses of tin

One of the most well-known uses of tin is soldering. The low melting point allows soldering at home. For soldering, this metal is sold in the form of small rods with a diameter of up to 10 mm.

Due to its physical characteristics, this metal can be stored in liquid form under normal conditions. The low melting point of tin allows the metallic liquid to be sealed into glass ampoules for laboratory or other research.

Tin smelting

Tin is quite easy to melt in large quantities and cast into a mold of graphite or any other material. The average melting point of tin does not exceed 240°C. The basic requirements for material for molds are as follows:

• the substance should not be wetted with liquid tin;
• the material must withstand temperatures of 250°C without collapsing or changing its shape.

Molten metal is capable of oxidizing in open air, and the solid is quite resistant to oxygen corrosion. Sometimes this property is used to apply a metal layer to tin products. But unlike zinc coating, tin coating does not provide the product with electrochemical protection - in the event of a scratch, corrosion will more quickly corrode the surface with a tin coating rather than with a zinc coating.

Tin for soldering

The melting temperature depends on the amount and composition of impurities in the rod. You can find out what the melting point of tin is from the table of the most common alloys.

Three-component alloys based on lead, silver and tin have proven themselves well in electrical engineering. The percentage of impurities in solder varies: standards for additives have not yet been developed. All manufacturers agree on one thing - the tin content in the alloy should not be less than 95%. The melting point of tin solder in this composition ranges from 217-221° C.

Source: https://crast.ru/instrumenty/temperatura-plavlenija-olova-v-gradusah-celsija

Melting temperature of tin for soldering, POS-40 and POS-60 solder, technical characteristics

Solder is a metal or mixture of metals used in soldering to join parts together. Typically, alloys based on tin, copper and nickel are used. Tin-based solder is included in the group of low-melting solders.

And the melting temperature of the solder here does not exceed 450 °C. These compounds are widely used to work with radio equipment.

Solders based on tin and lead are very common; they are widely used in our metal industry: the abbreviation POS.

To assemble homemade devices of the simplest design, the most common solder POS-61 or similar is sufficient. The alloy can be obtained from an old printed circuit board from an electronic device and assembled with a soldering iron from the soldered contacts.

Types and characteristics of solders

They are soft (low-melting) and hard. For installation of radio equipment, low-melting materials are used, with a melting point of 300−450 °C. Soft solders are inferior in strength to hard solders, although they are the ones used for assembling electrical appliances.

Low-melting alloys are usually an alloy of lead and tin primarily. There are few alloying elements.

Impurities of other metals are introduced to obtain certain characteristics:

• plasticity;
• melting point;
• strength;
• corrosion resistance.

The number in the brand designation indicates the percentage of tin it contains. So, the technical characteristics of POS-40 solder are such that it contains 40% Sn, and POS-60 - 60%.

If the brand is unknown, the composition can be assessed by indirect signs:

• The melting point of POS is 183−265 °C.
• If the solder has a metallic sheen, it means there is a lot of Sn in it (POS-61, POS-90). If the color is dark gray and the surface is matte, this indicates a high lead content, which is what gives the grayish tint.
• Solders containing large amounts of lead are very ductile, and tin imparts strength and rigidity.

Use of tin-lead group alloys

These alloys include the following:

• POS-90 contains: Pb - 10%, Sn - 90%. Used for repairing medical equipment and food utensils. There is little toxic lead, as it should not come into contact with food and water.
• POS-40: Pb - 60%, Sn - 40%. Mainly used for soldering electrical equipment and galvanized iron products; it is also used to repair radiators, brass and copper pipelines.
• POS-30: Sn - 30%, Pb - 70%. Used in the cable industry, for soldering and tinning and zinc sheeting.
• POS-61: Pb 39%, Sn 61%. Like with POS-60. There's not much difference.

Using POS-61, tinning and soldering of printed circuit boards of radio equipment is carried out. This is the main material for assembling electronics. It begins to melt at 183 °C, complete melting at 190 °C. You can solder with this solder using an ordinary soldering iron without fear that the radioelements will overheat.

POS-30, POS-40, POS-90 melt at 220−265 °C. For many radio-electronic elements this temperature is subcritical. It is better to assemble homemade electronic devices with POS-61, whose foreign analogue can be considered Sn63Pb37 (where Sn is 63% and Pb is 37%). It is also used to solder radio equipment and homemade electronics.

Solders are usually sold in tubes or coils of 10-100 g. The composition of the alloy can be read on the packaging, for example: Alloy 60/40 (“Alloy 60/40” - POS-60). It looks like a wire with a diameter of 0.25-3 mm.

It often contains flux (FLUX), which fills the core of the wire . indicated as a percentage and amounts to 1−3.5%. Thanks to this form factor, there is no need to supply flux separately during operation.

A variety of POS - POSSu is a tin-lead alloy with antimony, and is used in the automotive industry, in refrigeration equipment, for soldering electrical equipment elements, electrical machine windings, cable products and winding parts; Suitable for soldering galvanized parts. In addition to lead and tin, the alloy contains 0.5−2% antimony.

As the table shows, POSSU-61−0.5 is most suitable for replacing POS-61, because its complete melting temperature is 189 °C. There is also a completely lead-free , tin-antimony POSu 95−5 (Sb 5%, Sn 95%) with a melting point of 234−240 °C.

There are solders designed specifically for soldering parts that are highly sensitive to overheating. The most “high-temperature” among low-temperature ones is POSK-50−18 with a melting point of 142−145 °C. POSK-50−18 contains 8% cadmium, 50% tin and 32% lead. Cadmium enhances corrosion resistance, but at the same time imparts toxicity .

In descending order of temperature comes ROSE (Sn 25%, Pb 25%, Bi 50%), marked POSV-50. T pl. - 90−94 °C. Designed for soldering brass and copper. This alloy contains 25% tin, 25% lead, and 50% bismuth.

The ratio of metals in percentage may vary slightly, and their quantity is usually indicated on the package in the “Composition” column. This solder is extremely popular among electronics engineers. Used when dismantling/installing elements sensitive to overheating.

Among other things, the alloy is ideal for tinning the copper tracks of a brand new printed circuit board.

Used in protective fuses in radio equipment.

An even lower temperature WOOD alloy (Sn 10%, Cd 10%, Pb 40%, Bi 40%). Melting point - 65−72 °C. Since the alloy contains 10% cadmium, it is toxic, unlike ROSE.

Both ROSE and WOOD are quite expensive solders.

Solder paste

Source: https://tokar.guru/metally/temperatura-plavleniya/temperatura-plavleniya-pripoya-i-tehnicheskie-harakteristiki.html

At what temperature does tin melt: chemical element and its properties, boiling and melting points, color

Tin is a soft, silvery-white metal. It is so malleable and pliable that its sheets a thousandth of a millimeter thick can be rolled into a tube. This material is called tin paper. In D.I. Mendeleev’s periodic table of elements, this element corresponds to number 50, atomic weight 118.69 and the sign “Sn” (from the Latin stannum). There are 10 known stable isotopes. The metal is obtained mainly from the mineral cassiterite, which is tin dioxide.

The metal alloyed with lead is mainly used for soldering. It is also used as an anti-corrosion coating for food steel containers as it is non-toxic. Composites containing tin are used as fungicides, paints, toothpaste (SnF2) and ceramics.

Element history

This element was discovered in 1854 by Halus Pelegrin. However, its use began long before this date in the Middle East and Balkans around 2000 BC. During that era, bronze (an alloy of tin and copper) was discovered, which gave its name to the Bronze Age. They made weapons and tools from bronze, which were more effective than stone and bone.

In ancient times, the production of bronze led to the development of trade between different countries. There are also references to this metal in the Old Testament. Thus, in Mesopotamia they made bronze weapons, and in Ancient Rome they coated the inner surface of copper vessels with tin to increase their corrosion resistance.

General properties of tin

All the properties of this metal can be divided into two large groups: physical and chemical.

physical characteristics

It is a silvery, malleable metal that oxidizes easily at ambient temperatures, causing the color of tin to change to dark gray.

If you bend a plate of this metal, you can hear a characteristic sound, the so-called “tin cry,” which arises due to friction between its constituent crystals.

One of its pronounced characteristics is a sharp deterioration in mechanical properties under certain conditions, called “tin plague”: below a temperature of -18 ° C, the metal is destroyed, and it begins to look like a gray powder.

Pure tin has two allotropic modifications: gray and white. The gray modification has a cubic crystal structure, is a semiconductor, is very brittle, has low density and is stable at temperatures below 13.2 °C. The white allotropic modification has a tetragonal crystal structure, conducts electricity well and is stable at temperatures above 13.2 °C.

Metal melts at a relatively low temperature of 232 °C (for comparison: iron melts at 1535 °C). In this case, it is necessary to understand, when answering the question at what temperature tin melts, that it is its white allotropic modification that melts. Despite the low melting point, the metal boils at a relatively high temperature of 2602 °C (iron boils at 2750 °C).

Chemical properties

The most important mineral is cassiterite, SnO2. However, ore deposits with a high percentage of this mineral are currently unknown. Most of the world's cassiterite is mined from low-quality sediment deposits.

It is from this mineral that tin is obtained on an industrial scale. To do this, cassiterite is crushed to obtain its concentrate, and then it is smelted along with coke, quartz and lime in a blast furnace.

After this, the castings in the form of blocks undergo final cleaning to remove impurities of bismuth, copper and iron.

The chemical element tin reacts well with both strong acids and strong bases, but is relatively inert in neutral solutions. It is subject to corrosion in the presence of oxidizing environments; in the absence of oxygen, the metal practically does not corrode. During oxidation, a dense oxide film is formed on the surface of the metal, which protects the rest of it from further oxidation.

If an acidic environment is formed when salts are dissolved in water, then tin reacts in the presence of oxidizing agents or air. These salts include chlorides, for example, aluminum and iron. Most non-aqueous liquids, such as oils and alcohols, have little or no reaction with tin. Tin itself and its simple inorganic salts are not toxic, however, some organic composites are toxic.

Tin(II) oxide, SnO is a black-blue crystal that dissolves in acids and bases. It is used to produce salts in electroforming and glass production.

Tin(IV) oxide, SnO2 is a white dust that is insoluble in acids. It is used as an indispensable component for coloring pink, yellow and brown ceramics, as well as dielectrics and refractory alloys.

It is an important agent in polishing marble and other decorative stones.

Tin(II) chloride, SnCl2 is the main ingredient in stannous acid for soldering. Tin(IV) chloride, SnCl4 is used as a chemical ingredient to add weight to silk fabric, as well as to stabilize some perfumes and color stabilize soaps, and SnF2, which is white in color and soluble in water, is used as an additive in toothpastes.

Organic chemical compounds based on this element are those in which at least one tin-hydrogen bond, Sn-H, is present, and in which the metal exhibits an oxidation state of +4. Organic compounds that have found their application in industry have the following chemical formulas:

• R4Sn;
• R3SnX;
• R2SnX2;
• RSnX3.

Here R is an organic group, for example, methyl, ethyl, butyl and others, and X is an inorganic element, for example, chlorine, oxygen, flor and others.

Tin-based alloys

Tin-based alloys are also known as white metals and typically contain copper, antimony and lead. Alloys have different mechanical properties depending on their composition.

Tin-lead alloys have found commercial use in a wide range of compositions. Thus, 61.9% tin and 38.1% lead correspond to a eutectic composition, the solidification degree of which is 183 °C.

Alloys with a different ratio of these metals melt and crystallize over a wide temperature range when there is an equilibrium between the solid and liquid phases. With such crystallization, solid segregations begin to form in the melt, which lead to the formation of various structures.

An alloy of eutectic composition, since it has the lowest melting point, is used as a fuse against overheating of electronic components.

There are also alloys in which, in addition to the indicated metals, there is a small amount of antimony (up to 2.5%). The main problem with alloys based on tin and lead is their negative impact on the environment, so recently their substitutes have been developed that do not use lead, for example, alloys with silver and copper.

Alloys of tin, lead and antimony are used for decorative ornaments, and some alloys of tin, copper and antimony are used as a lubricant to reduce friction in bearings due to their antifriction properties. In addition to the above alloys, tin is used in bronze alloys and in alloys with titanium and zirconium.

Using the element and its connections

All areas of human production in which this element is directly or indirectly used are listed below:

• Protection against corrosion and mechanical impact of steels and other metals, for example, in the production of cans;
• Reducing the fragility of glass, as well as in the production of mirrors;
• In chased patterns on various dishes;
• Use in fungicides, paints, toothpastes and various pigments.
• When producing various alloys, for example bronze.
• For low temperature or soft soldering;
• Contains lead in the production of metal sheets for musical instruments;
• In the production of labels for various products;
• In alloys that protect electrical devices and electronic microcircuits from overheating;
• In the ceramic industry for the production of enamels as a matting agent.
• In capsules for sealing wine bottles. The production of such capsules expanded after the ban on the use of lead in the food industry.

Effects of exposure to tin compounds

The activity of compounds with this element, one way or another, affects both the human body and the environment.

On human health

As already mentioned, the most dangerous to human health are organic chemical compounds of tin. These substances are widely used in industry, for example, in the production of paints, plastics and agricultural pesticides. In addition, the production volumes of organic compounds with this metal are constantly growing, despite the fact that the consequences of poisoning with them are known.

The effects of these substances on humans are varied, it all depends on the type of compound and on the individual characteristics of the body. The danger of a compound correlates with the length of the bond between the metal and the hydrogen; the longer the bond, the less dangerous the compound. In this regard, the most dangerous organic substance is considered to be a tin compound with three ethyl groups, the hydrogen bonds of which are relatively short.

These substances can enter the human body through food, airborne droplets, or simply touching them. The following effects of organic tin compounds on the human body are known:

• If you are in a room containing vapors of this metal, severe irritation of the upper respiratory tract, skin and eyes;
• Headaches, stomach pain and lack of appetite;
• Nausea and vomiting;
• Problems with urination;
• Heavy sweating and shortness of breath.

The following effects can lead to more serious consequences:

• Depression;
• Liver problems;
• Immune system dysfunction;
• Damage to cell chromosomes and lack of red cells in the blood;
• Brain damage (sleep disturbances, headaches, memory loss, irritability).

On the environment

Both tin atoms and the metal itself in a pure state are not toxic to any organism on earth, in turn, almost all compounds with this element of an organic nature are harmful.

These compounds can remain in the environment for long periods of time. They are quite stable and practically do not decompose under the influence of microorganisms, due to their strong hydrogen bonds.

No matter how small the concentrations of this metal compounds in soil and water are, in view of the above, they are constantly growing.

Organotin compounds are known to cause great harm to aquatic ecosystems as they are toxic to fungi, algae and phytoplankton.

Phytoplankton is an important part of the aquatic ecosystem, since it produces oxygen for all other living organisms in this system, and is also an important part in the food chain.

The toxicity of tin compounds varies among living things, for example, tributyl tin is poisonous to fish and fungi, while the most toxic compound to phytoplankton is triphenol tin.

It is also known that organic compounds of this element have a negative effect on the growth and reproductive function of animals and disrupt the functioning of enzymes. Such compounds accumulate mainly in the upper layers of soil and water.

Source: https://obrabotkametalla.info/splavy/temperatura-plavleniya-olova

Melting point of tin: properties of the element and its scope of application

All metals have their own special properties and characteristics. Many of us know from school that every metal has its own melting point. In a thermodynamic process, the crystal lattice in metals is destroyed, and they pass from a solid state to a liquid state.

Metals are divided into groups depending on their melting point - light, medium and refractory. Tin belongs to the first group of fusible metals, but we will try to find out at what temperature this rare chemical element melts.

Tin

The rare metal tin ranks 50th and belongs to the main subgroup of group IV in the table of the fifth period. Its mass is 118.710, in its pure form it appears as a silvery-white metal, soft, ductile and malleable, it is highly resistant to corrosion. The rare element is ranked 47th in distribution in the earth's crust.

The main deposits in the world are located in the countries of Southeast Asia - China, Thailand, Malaysia, Indonesia. There are also large deposits in South America and Australia. On the territory of Russia, there are reserves of tin ore in Chukotka, Khabarovsk and Primorsky Territories, and Yakutia.

A little history

This rare metal became familiar to people even before our era, since it was mentioned in the Bible. It was inaccessible to people, so it was very expensive ; tin products are rare among the products of archaeological excavations of Ancient Rome and Greece.

It began to be used in the Bronze Age; tin at that time was a strategic metal, since it was part of bronze products. The recipe for the alloy of copper and tin has been preserved to this day, but now they have begun to add aluminum, lead and silicon. The resulting alloy was very hard, cast well, and was easy to forge and machine. At that distant time, bronze was considered the most durable metal known to people of that time.

Jewelry and dishes were made from this alloy, but it was very expensive. Much of the long period of development of society since the discovery of tin is associated with the rare element.

Properties of tin, its melting point

In nature, a rare metal can be found in two forms - in rocks and minerals. Most often, the element is found in the form of tin stone - an oxide compound. Previously, it was smelted from ore that was found in the upper layers of the earth's crust. Nowadays, such minerals have practically disappeared, so the process of mining tin has become much more difficult.

• Until the moment when the metal enters the smelting department, ore and placers that contain tin undergo an enrichment process. After this, the concentrate is sent to kilns and only then melted.
• The rare element has a low melting point; the melting process begins at +231.9°C; at a temperature of +231.0°C the metal remains solid. Even when cooled, it bends easily, and when heated it becomes pliable like plasticine. The boiling process of tin begins when the temperature is many times higher than the melting point - 2630 ° C.
• The element comes in white and gray colors; it acquires a darker color when it turns into a powder state; in powder, the density of the element is much lower than when it is in a solid state.

During the smelting process, slags, fluxes, and additives are used in order to obtain the desired grade and quality of metal. Its low melting point made it a strategically important metal. It can easily participate in the formation of alloys with other materials due to its low melting point. Ultimately, alloys are easily processed, then they participate in the connection of structural units and parts with a good sealed seam.

Applications of tin

• This element is often used as a protective layer in the nuclear industry.
• It is also used in the glass industry as a glass polish ; it is poured in a liquid state into a container with a melt.
• The printing industry uses an alloy of tin with antimony and lead to create printed type.
• Tin is rolled into foil; the element is used in the production of pipes and various parts to give them anti-corrosion resistance, because tin does not rust.
• The rare element conducts heat well; for example, it is often used in the production of cans. You can store food in such containers for a long time, since tin is a non-toxic element. The dishes are not subject to destruction for a long period of time.
• It is also used in the weaving industry, but only as metal salts . It is mainly used in the production of natural silk and for printing on calico fabric.
• The element has also found application in medicine, for example, in dentistry for reinforcing certain types of fillings. The rare metal is present even in the human body; its lack can negatively affect growth, for this reason it begins to slow down.

Conclusion

Today, tin is used in many industries, since the metal has a number of unique properties . Thousands of years later, the rare chemical element is still in demand both in its pure form and in alloys with other metals.

Source: https://stanok.guru/cvetnye-metally-i-splavy/olovo/pri-kakoy-temperature-proishodit-process-plavleniya-olova.html

Solders

Radio electronics for beginners

At the beginning of their amateur radio activities, many novice radio amateurs rarely ask themselves about the types of solders and what their properties are.

To assemble the simplest homemade devices, the most common POS-61 or similar is sufficient. As they say: “It would be something to solder with”

You don't even have to buy solder. It is enough to take an old printed circuit board from some electronic device and assemble it with a heated soldering iron tip from the soldered contacts.

This method of “extraction” is especially relevant for those who live far from cities and large populated areas, where there is no opportunity to visit a radio store.

Solder collected from printed circuit boards

But still, solder to solder is different. In his practice, a person dealing with electronics must understand the issue of his choice. Therefore, we will consider in detail what types of solders there are, what they are used for, which one is better to use for installing electronic circuits and repairing household radio equipment.

What types of solders are there?

Solders are divided into soft (low-melting) and hard. For the installation of radio equipment, low-melting ones are used, i.e. those whose melting temperature ranges from 300 to 4500C. Soft solders are inferior in strength to hard solders, but they are used for assembling electronic devices.

Solder is an alloy of metals. For low-melting solders, this is usually an alloy of tin and lead. It is these metals that make up the majority of the alloy. Alloying metals may also be present in it, but their quantity in the composition is small. Impurities of other metals are introduced into the alloy to obtain certain characteristics (melting point, ductility, strength, corrosion resistance).

The most widely used type of solder is POS (Tin-Lead Solder). Next, a brief designation of its brand is followed by a number that shows the percentage of tin in it. So POS-40 contains 40% tin, and POS-60, respectively, 60%.

It happens that solder of an unknown brand comes into use. Its composition can be roughly assessed by indirect signs:

• Solders of the tin-lead group have a melting point of 183 – 2650C.
• If the solder has a bright metallic sheen, then it has a fairly high tin content (POS-61, POS-90). And, conversely, if it is dark gray in color and the surface is matte, then this indicates a high lead content. It is lead that gives the surface a peculiar grayish tint.
• Solders containing a lot of lead are very ductile. For example, a solder rod with a diameter of 8 mm. with a high lead content (POS-30, POS-40) is easily bent by hand. Tin, unlike lead, gives the alloy strength and rigidity. If there is a lot of tin in the alloy, then it will no longer be possible to bend such a rod easily.

POS-40 (bar)

Let's consider the purposes for which solders of the tin-lead group (POS) are used.

• POS-90 (Sn 90%, Pb 10%). Used for repairing food utensils and medical equipment. As you can see, it contains a small lead content (10%), which is quite toxic and its use in things that come into contact with food and water is unacceptable.
• POS-40 (Sn 40%, Pb 60%). Mainly used for soldering electrical equipment and parts made of galvanized iron, used for repairing radiators, brass and copper pipelines.
• POS-30 (Sn 30%, Pb 70%). It is used in the cable industry, and is also used for tinning and soldering zinc sheets.
• And finally, POS-61 (Sn 61%, Pb 39%). Same as POS-60. I don't think there's much difference between them.

POS-61 is used for tinning and soldering printed circuit boards of radio equipment. It is mainly used as a material for assembling electronics. Its melting point starts at 1830C, and complete melting is achieved at a temperature of 1900C.

Soldering with such solder can be done using a conventional soldering tool without fear of overheating of the radioelements, since its complete melting is achieved already at 1900C.

POS-30, POS-40, POS-90 completely melt at temperatures of 220 – 2650C. For many radio-electronic components, this temperature is subcritical. Therefore, it is better to use POS-61 for assembling homemade electronic devices.

A foreign analogue of POS-61 can be considered Sn63Pb37 (63% tin, 37% lead). It is also used for soldering radio equipment and for making homemade electronics. Radio amateurs choose it as an alternative to the domestic POS-61.

As a rule, any solder is sold in coils or tubes of 10 ~ 100 grams. The composition of the alloy is indicated on the packaging, for example, like this: Alloy 60/40 (“Alloy 60/40” - also known as POS-60). It has the shape of a wire of different diameters (from 0.25 to 3 mm).

It is also not uncommon that it contains flux (FLUX), which fills the core of the wire. flux is indicated as a percentage (usually from 1 to 3.5%). This form factor is very convenient. During operation, there is no need to separately supply flux to the soldering area.

One of the varieties of POS solders is POSSu . Yes, if you say it out loud, it doesn’t sound very presentable.

But, despite this, tin-lead solder with antimony (this is how the abbreviated designation stands for) is used in the automotive industry, in refrigeration equipment, for soldering the windings of electrical machines, elements of electrical equipment, winding parts and cable products. Well suited for soldering galvanized parts. In such an alloy, in addition to lead and tin, there is from 0.5% to 2% antimony.

Solder	Initial melting t0 (Solidus)	Full meltdown (Liquidus), t0
POSSu-61-0.5	183	189
POSSu-40-2	185	229
POSSu-40-0.5	183	235
POSSu-30-2	185	250
POSSu-30-0.5	183	255

As we can see from the table, POSSu-61-0.5 solder is most suitable for replacing POS-61, since it has a complete melting temperature of 1890C.

It is worth noting that there is also a completely lead-free tin-antimony solder POSu 95-5 (Sn 95%, Sb 5%). Its melting point is 234 – 2400C.

Low temperature solders

Among the solders, there are also those that are designed specifically for soldering components that are very sensitive to overheating. The most “high-temperature” among low-temperature ones is POSK-50-18 . It has a melting point of 142–1450C. POSK-50-18 contains 50% tin and 18% cadmium. The remaining 32% is lead. The presence of cadmium in the alloy increases corrosion resistance, but also makes it toxic.

Next in decreasing melting temperature is the ROSE alloy (Sn 25%, Pb 25%, Bi 50%). Marked as POSV-50 . Its melting point is lower than the boiling point of water and is 90 – 940C. It is designed for soldering copper and brass. In the composition of the ROSE alloy, tin occupies 25%, lead – 25%, bismuth – 50%. The percentage of metals in the alloy may vary slightly. Usually indicated in the “Composition” column on the packaging.

This alloy is very popular among radio mechanics and, in general, among all electronics engineers. It is used for dismantling/installing elements sensitive to overheating. Among other things, this alloy is ideal for tinning copper tracks of a newly manufactured printed circuit board.

Finds application in protective fuses that can be found in any radio equipment.

An even lower temperature alloy is WOOD (Sn 10%, Pb 40%, Bi 40%, Cd 10%). Its melting point is 65 – 720C. Since the WOOD alloy contains cadmium (10%), it is toxic, unlike the ROSE alloy.

It is worth noting that ROSE and WOOD alloys are quite expensive.

At what temperature does tin melt and crystallize?

One of the very first metals discovered in antiquity was tin. It has a silvery-white color with a small mass. Dishes made from it perfectly retain the smell and taste of drinks.

This metal was used much earlier than iron was subsequently discovered, and its alloy with copper (bronze) is the first alloy substance created by man.

This happened due to the fact that the melting point of tin is very low, which made it possible to process the metal even at the inception of metallurgy.

Properties and features of tin

Tin alloys have a low coefficient of friction, which is why they are used in a variety of antifriction materials. In addition, they can impart this property to other substances. This significantly extends the service life of mechanisms and machines, significantly reducing friction losses. An interesting feature of this material is its volume increase by 25.6% at a temperature of + 13.2 °C. This metal is called gray.

When the temperature drops to – 33.0 °C, the substance crystallizes and turns into a powder state. When gray and white tin interact, properties are transferred to the white metal. A variety of tin alloys are widely used in the electrical industry.

There is a clear answer to the question at what temperature tin melts: + 231.9 °C or 505.1 kelvin. This is very convenient for radio amateurs, because parts at this temperature can be soldered without any problems even at home.

The melting point at which tin becomes liquid is low, which makes it easier to use.

This substance is of great interest due to its good corrosion resistance. Tin coating is the oldest way to protect a variety of metal objects, including cans. In addition, this element has the property of combining many metals, giving them resistance to external influences.

This is used for tinning various dishes and other household utensils, as well as for electrical technicians. Tin-lead alloys are soft components, which is convenient when soldering radio components. These solders may have different numbers of components and corresponding designations.

For example, pos-61 means that the tin component is 61%, and the lead component is 39%.

The human body contains tin substances in the bones, where they help renew bone tissue. For normal functioning, the body needs to receive about 2-10 mg of metal per day every day. This macronutrient is contained in the food we eat, but only up to 5% of the total incoming amount is absorbed.

Melting temperature

Particularly famous are the compounds used as solder by radio amateurs. The melting point in the POS-40 alloy is + 235.0 °C. The lead contained in solders is a rather soft material, having a gray color with a light tint. It melts at +327.0 °C, which makes it an ideal component for tin. POS-61 solder can melt at a temperature of + 191.0 °C, which is very convenient for soldering small radio components.

Experts know at what temperature tin melts. This value is + 231.9 °C, and at + 231.0 °C it remains solid. The boiling point of this substance is much higher - 2,600 degrees Celsius. Depending on the components included in the tin alloy, the melting temperature changes.

This material bends perfectly even when cold, and when heated, it begins to acquire the properties of plasticine. The melting points of lead and tin differ, but their alloys have a wide range of applications. When melting, special fluxes, slags, and additives are used to obtain the required degree of quality and type of metal.

Due to its ability to melt at low temperatures, it is a strategically important raw material. Alloys containing a tin component are very easy to process and are used when connecting structural parts and assemblies with a sealed seam.

The most well-known household compounds include solders, the melting point of which tin and lead depends on their quantity.

Application and recycling

The main advantage that determines the scope of application of the tin substance is its high resistance to corrosion. It transfers this property to other metals participating in the alloy. This ability to resist chemically aggressive substances makes the material very valuable in protecting steel products. The thinnest layer covers almost half of all steel sheet produced.

This metal is used in the production of thin-walled pipes, which are used exclusively at positive temperatures. A limitation of the scope of application is the low crystallization temperature of tin.

Household products contain tin in plumbing fixtures, various fittings and other accessories. The material is highly hygienic, has a low melting point of tin, and also has very low thermal conductivity compared to steel.

Due to these characteristics, it is actively used for the manufacture of washbasins and bathtubs.

This substance is present in household dishes, jewelry, as well as small decorative and household items. This is due to the good melting of the material at low temperatures, malleability and soft color. Bronze alloys have excellent strength as well as high corrosion resistance. This makes bronze an excellent building and decorative material.

In addition to solders, which are convenient to melt at home and in industrial production, alloys are even used for the production of musical instruments. Church bells and organ pipes are cast from various alloys. The tone of the products depends on the number of constituent elements. The low solidification temperature of the material and ease of processing make it possible to produce unique musical products.

Old tin cans are used for recycling. They have a protective tin coating with some impurities. Their quantity for food packaging is strictly limited. The value of the tin composition when tinning a tin can should not exceed 0.14%, and for lead this figure is 0.04%.

For health safety, special varnishes are additionally used that protect the metal base from destruction under the influence of salt, sugar, and organic acids. The average jar contains about 0.5 g of the tin component. On a global scale, this is a very impressive figure.

The share of this recycled raw material in developed countries reaches 30%.

Tin is used in almost all areas of modern production. Millennia after its discovery, the metal remains a sought-after substance with a wide range of unique properties.

Recommended reading:

Why do you need rosin (flux) when soldering?

Source: https://oxmetall.ru/pajka/temperatura-plavleniya-olova

Melting point of tin and alloys with lead, features of tin and manufactured solder - Machine

Everyone knows from school that tin with the chemical symbol “Sn” is used for soldering microcircuits and other radio components. The main requirement for this alloy is a low melting point.

This is because the solder must melt during the process, not the part being joined.

Pure tin with a melting temperature of 232 °C is quite suitable for these purposes, but in practice, pure tin is not actually used for soldering due to its high cost; alloys with lead and other metals are more often used.

Characteristics

Tin is indispensable in the production of electronic devices. Due to its properties, it is used for welding components in radio engineering. The alloy, called Eutectica, consists of lead (Pb), silver (Ag), copper (Cu) and nickel (Ni). Thanks to these additives, tin melts at different temperatures depending on the percentage of each of them.

Tin for soldering

Tin is soft and malleable, but very resistant to corrosion and does not form rust, has very good electrical conductivity and a relatively low melting point. All these characteristics make it indispensable for creating electronic devices.

The soldering process takes place in soft welding, which consists of combining two base elements by introducing a third element with a lower melting point into the base.

For example, soldering a copper circuit board pad to a capacitor leg uses molten tin, which melts at a much lower temperature than the base elements.

During the heating process, liquid tin, due to its capillary properties, is attracted to the base components, and then cools in soft soldering mode.

Eutectica alloy

Types of solders and fluxes

In our country, the POS brand of solder has become widespread - an alloy of tin Pb and lead Sn. Depending on the type, cadmium, nickel, copper, and other metals may be added to it.

PIC is mainly produced in the form of rods, wires, balls and paste. Its chemical composition is strictly regulated by GOST 21930-76.

In Russia, the following types of solder are widely used: POS18, POS30, POS50, POS90, which are soft alloys with a melting temperature of up to 300 degrees.

POS brands

POS-18

Solder is regulated by state standards; in addition to Pb (0.8%) and Sn (17-19%), it contains impurities of many metals. Regulatory authorities strictly ensure that the manufacturer limits the presence of toxic arsenic in the composition, which reduces the fluidity of the liquid alloy and increases fragility under conditions of alternating loads.

Composition of POS-18 impurities in percent:

• Cu - 0.1;
• Bi0 - 0.05;
• S—0.02;
• Fe - 0.02;
• Al, Ni, Zn - 0.002 each.

Technical data:

1. Density—10.3g/cm2.
2. The resistivity indicator is 0.200 µOhm•cm.
3. The Brinnel hardness index is 11 HB.
4. Thermal conductivity—0.37 kcal/cm*C*deg.
5. T at which the solder will melt solidus/liquidus—183/285 C.

Solder Advantages:

• Wide area of ​​alloy in liquid state;
• reduced content of impurities that cause brittleness;
• corrosion resistance of the soldering area, which is important for parts located in humid environments.

Disadvantages of POS-18:

• Special solder, not mass produced.
• The presence of harmful additives in the composition - Pb.

POS-18

POS-18 belongs to the universal alloys and is a substitute for antimony-free alloys; it is used:

• For the production of radio equipment;
• soldering low power printed circuit boards;
• car body repair in the form of tinning;
• connections of units made of copper-zinc alloys;
• repair of equipment in heating systems: boilers, radiators and other heating elements.

The price of POS-18 solder as of September 1, 2019 is from 710 rubles/kg.

POS-30

Solder is standardized by GOST 21930.76 / 21931.76 and belongs to soft alloys with a melting temperature of 256.0 C. Its properties are similar to grades with POS-40 and 50 and consists of Pb and Sn in a percentage ratio of 30:70, as well as other elements no more than 1 %. It differs from pure tin in its dark color and increased hardness of the alloy.

Solder POS-30

Composition of impurities in percentage:

• Sb - 0.1;
• Cu - 0.05;
• Bi0 - 0.2;
• S, As, Fe - 0.02 each;
• Al, Zn - 0.002 each.

Technical data:

1. Density - 9.72 g/cm2.
2. The resistivity indicator is 0.185 µOhm•cm.
3. The Brinell hardness index is 12 HB.
4. Thermal conductivity - 0.37 kcal/cm*C*deg.
5. Solidus/liquidus melting temperature - 183/256 C.

Solder Advantages:

• High fluidity;
• low melting temperature;
• low resistance allows you to work with small parts;
• high impact strength equal to pure tin;
• high scope of application, with the possibility of replacing expensive materials, for example, for soldering zinc or brass plates;
• Possibility of use for repairing household appliances.

The disadvantage of POS-30 is the presence of harmful additives in the composition - Pb.

The price of POS-30 as of September 1, 2019 is from 766 rubles/kg.

POS-50

It is produced in accordance with the requirements of GOST 21931.76, it is distinguished by a practically equal ratio of lead and tin.

Solder POS -50

Composition of POS-50 impurities in percent:

• Sb - 0.8;
• Cu - 0.1;
• Bi - 0.05;
• As - 0.05;
• S, Fe - 0.02 each;
• Ni, Al, Zn - 0.002 each.

Technical data:

1. Density - 8.87 g/cm2.
2. The resistivity indicator is 0.158 µOhm•cm.
3. The Brinell hardness index is 14 HB.
4. Thermal conductivity - 0.48 kcal/cm*C*deg.
5. Solidus/liquidus melting temperature - 183/209 C.

Solder Advantages:

• Good fluidity;
• good thermal and electrical conductivity;
• Possibility of use in wet environments;
• good ductility of the seam allows it to be used for products with increased requirements for tightness, for example, in measuring instruments and low-power PC circuits.

Disadvantages of POS-50:

• Ineffective when soldering thick products due to unstable heating; the presence of harmful additives in the composition - Pb;
• accelerated crystallization of the melt does not make it possible to use the alloy in manual soldering technology.

The price of POS-50 solder as of September 1, 2019 is from RUB 1,102.00/kg.

POS-90

The solder is characterized by low thermal conductivity and high hardness, which is explained by the high content of tin 90, the material is silver in color, which gives the resulting joints an aesthetic appeal.

Solder POS - 90

Composition of POS-90 impurities in percent:

• Sb - 0.1;
• Cu - 0.05;
• Bi - 0.2;
• As - 0.01;
• S, Fe - 0.02 each;
• Ni, Al, Zn - 0.002 each.

Technical data:

1. Density - 7.6 g/cm2.
2. The resistivity indicator is 0.120 µOhm•cm.
3. The Brinell hardness index is 15.4 HB.
4. Thermal conductivity - 0.13 kcal/cm*C*deg.
5. Solidus/liquidus melting temperature - 183/220 C.

Advantages of POS-90:

• Wide range of applications from household, medical to industrial sectors;
• good fluidity;
• high level of wettability in the liquid state;
• low melting temperature;
• good electrical conductivity;
• good tightness, the ability to use in water and gas environments; good plasticity of the seam allows it to be used for products with high
• sealing requirements, for example in measuring instruments and low-power PC circuits.

The disadvantages of POS-90 are the presence of harmful additives in the composition (lead).

The price of POS-90 solder as of September 1, 2019 is from RUB 1,778.00/kg.

What is the melting point

Tin, which is used in electronics, is usually a eutectic type, meaning that it is an alloy with a lower melting point for each of its constituent elements. So, if there is a 60% tin alloy (melting temperature - 232 C) and 40% lead (melting temperature - 327 C), then the total melting temperature of the alloy will be approximately 183 C.

Melting tin

The most common solder used in EU countries for electronic work is 63/37 SnPb. It is a eutectic alloy with a melting point of 183 C. The 60Sn alloy has a working range of 183-238. There is a lower temperature alloy Sn43Pb43Bi14, which has a melting point of 144-163.

Solder composition

The lead contained in the alloy is gradually being phased out in accordance with new EU directives (RoHS and WEEE) and is being replaced by solders consisting of tin-antimony alloys. Already today in the EU many stores do not sell it. Things are different here for now; it will probably be many years before lead solder in our country is replaced forever.

Important! Lead-free alloy has a higher melting point than lead alloy and uses more aggressive fluxes. This means that the soldering iron must be made for lead-free soldering to ensure the correct temperature of around 230 C. Lead-free solder is generally about 20-50% more expensive than lead solder.

How to choose the right one

The choice of solder depends on the type of work and purpose of the finished product, as well as on the conditions under which the product will be used.
Criteria to consider before choosing solder for soldering:

1. Soldering iron type.
2. Wire size. Diameters vary from centimeters or millimeters, the size of the wire depends on the work being performed.
3. The flux cleans the soldering area, making it easier for the solder to flow and therefore a perfect solder joint. Flux changes surface tension as it increases adhesive properties in the solder joint.
4. Before purchasing, you need to know at what temperature tin melts for soldering.
   Compound. The debate about whether to use lead or lead-free solder on PCBs is still ongoing. Despite debates caused by environmental and health concerns, many electrical technicians use lead.

Note! The expiration date and industry guidelines require its use within three years from the date of manufacture. The expiration date is indicated on the product and can be found in the store upon purchase. If you use expired solder paste, oxidation may occur on the solder surface, rendering the connection ineffective.

Usage

Experts give useful tips that are very helpful for novice radio amateurs to solder correctly:

1. Choose solder with a minimum lead content.
2. It is necessary to ensure the cleanliness of the soldering iron tip; it should not have dirty deposits.
3. For cleaning, use a file or sandpaper. After cleaning, the tip is tinned with rosin.
4. It is not recommended to hold the device at the solder point for a long time, since the parts being connected can suffer high temperature damage. To reduce the harmful effect of T on the part, it is held with tweezers, which will act as a heat sink.
5. The product is cleaned before soldering, and the contact contacts are additionally tinned to ensure excellent adhesion.

Soldering technology

Additional Information. When soldering, safety precautions must be taken. Always wear safety glasses to protect your eyes from flying drops of hot liquid solder.

The tip of the soldering iron is very hot by design, exceeding 370 C. Do not allow the tip to come into contact with skin, clothing or other objects.

When working, you need to use a special holder for a soldering iron.

To summarize, we can say that soldering tin is still widely used in the domestic electronics industry and everyday life. The product is widely represented on the Russian and foreign markets, in the form of lead and lead-free solders. In order to protect the environment and the requirements of international organizations, consumption of the first type will be steadily reduced.

Source: https://regionvtormet.ru/beton/temperatura-plavleniya-olova-i-splavov-so-svintsom-osobennosti-olova-i-izgotavlivaemogo-pripoya.html

Solder POS 61: melting point of tin for soldering, composition and technical characteristics

Most novice radio amateurs who have not encountered soldering before are wondering what solders can be and how they differ from each other.

POS solder is a tin-lead alloy. Depending on the ratio of these elements, there are different markings. The most common is POS 61 solder.

Types of solders

Solder is not always necessary to purchase. You can use an old radio component and assemble it from the board tracks using a soldering iron tip. This option is perfect for those who live far from the city, where it is not possible to purchase the material in a store.

Standard lead solders.

However, they are different and differ in their properties and characteristics. In this regard, every experienced master should understand this issue. To solder parts, it is necessary to use special alloys - solders.

The latter have a lower melting point than individual parts of the products.

Such alloys are divided into two main categories depending on their melting point: soft and hard. The first type is widely used in radio electronics, both by amateurs and professionals.

Low-melting solders include solders with a melting point of less than 450°C. They are made from: gallium, indium, tin, bismuth, lead and cadmium. High-temperature ones melt when heated above 450°C. In any case, it is usually an alloy consisting of several metals and impurities.

The most common option is a tin-lead alloy called PIC. The numbers after the abbreviation indicate the percentage of tin.

You can distinguish one alloy from another without knowing the brand. For example, with a higher tin content, a characteristic metallic luster appears, and with a higher lead concentration, the color becomes dark gray.

In addition, the melting point of POS does not exceed 265°C. Another distinctive feature of alloys with a higher proportion of lead is their ductility and the ability to be easily bent by hand.

Classification of alloys is carried out in accordance with GOST standards.

Physico-mechanical properties of solders.

The most common are:

• solder POS 90;
• POS 61;
• POS 40;
• POS 30.

In fact, there are significantly more markings. There are several dozen of them. Each is written in such a way that the composition of the alloy becomes clear from its name; all are manufactured in accordance with GOST 21930-76 tin-lead solder.

It is worth noting that the alloys differ from each other not only in their chemical composition. Depending on the form of release, they come in ingots, wire, a tube with rosin, or in a rod.

For example, POS 61 solder can be sold in rods or in the form of wire of various diameters. It is important to understand that the ratio of lead to tin affects the melting point. This parameter largely determines the choice of the required alloy.

This flux contains no halogens. Thanks to this fact, it has significantly less harm to the health of masters.

The use of alloys of various grades is determined by the scope of their application. POS thirty and forty are considered soft. Their melting point does not exceed 300°C. Used in joining galvanized products, tinning, repairing electrical appliances, etc.

Bottom line

The melting point of tin makes this material an excellent solder. POS brand solders are particularly widespread. They are used in industry, in private workshops, and by radio amateurs.

Many brands of this solder allow you to choose the necessary alloy, which is ideal for solving almost any problem.

Source: https://tutsvarka.ru/oborudovanie/pripoj-pos

Melting point of lead and tin, characteristics of metals, melting point tables

Lead is a low-melting metal, so melting it is quite easy, even without special equipment. The main thing you need to know is what is the melting point of lead. The choice of container in which the melting will take place depends on this. For lead, an ordinary tin can is suitable, since the tin for it is made of steel, which melts at a temperature several times higher than that of the metal being smelted.

Lead and its properties

The dirty gray color of this metal is the result of the fact that an oxide film forms on its surface in a short time in the atmosphere. It is this that gives such a nondescript appearance to lead.

However, if you run a file over the surface of the metal several times, a shiny surface with a bluish tint will become visible under a thin layer of oxide film. This is a very soft and heavy material, it is almost one and a half times heavier than steel.

The density of lead is 11.34 g/cc, and the density of iron is 7.80 g/cc.

Lead was discovered in ancient times around 4000 - 4500 BC. In modern industry, it is obtained mainly by metallurgical methods from lead ores and concentrates.

Lead has a low melting point - only 327 °C, and a boiling point - 1749 °C. It is necessary to take into account the toxicity of lead vapor and the fact that this chemical element is poorly excreted from the body. The more molten lead is heated, the more it evaporates. Therefore, the room in which the melting takes place must be well ventilated.

It is due to its low melting point that lead is used in the manufacture of soft solders together with tin.

Tin Characteristics

Melts at 232 °C, boils at 2600 °C, perfectly alloys with various metals, and, due to its high ductility, can be forged well. Soldering tin is used as solder because it wets metals well. Industrial production of tin is much more difficult than lead, so it is much more expensive.

Unlike lead, tin looks much more attractive. This silvery-white metal is safe for human health. Tin is often used to cover the surfaces of metal products in places where they come into contact with food: dishes, tin plates, food foil and others.

However, tin dust and fumes can cause hazardous effects on the human body if inhaled. In addition to the production of food containers, tin is widely used in various solders and other alloys, for example, in antifriction and bearing alloys.

This material is much lighter than lead, its density is 7.3 g/cc.

Tin is polymorphic, meaning it can exist in various modifications depending on temperature. At temperatures below 13 °C, white tin (β-modification) turns into gray tin (α-modification). As a result of this phase transition, the shiny pewter pieces crumble into a gray powder. Moreover, upon contact with the powder, white tin becomes infected with it and turns into gray. This phenomenon was called the " tin plague ".

According to some reports, it was the main reason for the death of Robert Scott's expedition to the South Pole. Kerosene, stored in intermediate warehouses, leaked from canisters sealed at the seams with tin, which crumbled into powder in the frosts of the Antarctic. Thus, the expedition members were left almost without fuel.

Soldering alloys

Solders are classified according to various characteristics: degree of melting during soldering, manufacturing method, base metal, ability to flux, etc. Based on melting temperature, solders are:

1. Light alloy, melts at less than 145 °C.
2. Soft, melts at temperatures from 145 °C to 400 °C.
3. Solid, melting point above 400 °C.

Light alloys are used for soldering materials critical to overheating, such brands as Newton's alloy, Guthrie's alloy, Wood's alloy, POSV 32−15−53 can be mentioned.

Soft ones are used for tinning and soldering seams of dishes, electrical equipment, printed circuit boards, and heat exchanger tubes. The most common of them are tin-lead (see Table 1).

Hard solders provide high joint strength and are used for soldering load-bearing structures. These solders include copper-zinc (PMC-36, PMC-48, PMC-54), silver (PSr72, PSr70, PSr50, PSr50Kd, PSr12M) and others.

Tin-lead solders

An alloy of tin and lead with a tin content of 10 to 90% is called POS solder . The following designations of brands of such solders can be given:

• POS40 - contains 40% tin, the rest is lead, melts at 235 degrees, used in industry for tinning and soldering electrical equipment, galvanized steel products;
• POS90 - 90% tin, 10% lead, melts at 222 degrees, has found its application in the manufacture of tableware and medical equipment;
• POSSU 30−0.5 - 30% tin, 0.5% - antimony, the rest is lead, becomes liquid at 255 degrees, is used for tinning and soldering zinc sheets, ordinary and stainless steel, wires, radiators.

Depending on the percentage of tin and lead, the melting temperature of different brands of solder changes.

Melting metals

Melting is the process of a substance changing from a solid to a liquid state. Unlike alloys, in pure metals melting and solidification (crystallization) occurs at a constant, strictly defined temperature. It distinguishes between metals:

• low-melting , melts at temperatures up to 600 °C;
• medium-melting - from 600 °C to 1600 °C;
• refractory - over 1600 °C.

Table 2 indicates at what temperature lead melts, at what temperature tin and other metals melt.

Melting temperatures of metals (in °C). table 2

Source: https://chebo.biz/stroyka-i-remont/plavka-svintsa-i-olova-temperatury-plavleniya-metallov.html

Melting point of tin, industrial use

Tin is one of the metals of antiquity that can preserve the smell and taste of drinks. A light metal, silvery-white, one of the few that man began to use in prehistoric times. It was discovered before iron, and the alloy of copper and tin is most likely the first “artificial” material created by man.

Description of metal

Tin is a rare metal, found in small quantities in ores and sands, and is especially common in layers raised from the ocean floor. It ranks 47th in abundance among metals in the earth's crust.

To obtain it, ores are used whose content of this metal is about 0.1%. First, the ore is enriched (by magnetic separation or gravity flotation). Thus, the tin content increases to 40–70% . Then the concentrate is fired in oxygen to remove arsenic and sulfur impurities. The material thus obtained is reduced in electric furnaces using aluminum or coal.

About 40% of the world's tin production goes into the production of tin cans. The rest is used in metallurgy to produce various alloys. The most famous alloy is bronze, consisting of tin and copper. And only 7% of tin produced in the world is used in the form of chemical compounds.

Recycling and use

Recycling also takes place, with most of the metal coming from old tin cans, in which it is used as a coating. Due to the fact that this metal may contain impurities, which over time can pass into the product in a tin can, the content of tin and other elements in the production of food cans is strictly standardized.

According to sanitary standards, the content of foreign impurities in tin intended for tinning a tin can should not exceed 0.14% , and the amount of lead should not exceed 0.04%. But still, for preventive purposes, special varnishes are used that protect the metal from decomposition under the influence of organic acids, sugar, and salt.

Each jar contains approximately 0.5 g of this metal. But if you multiply this seemingly small number by the scale of production, you get tens of tons. In developed countries, the share of “recycled” tin in production is approximately 1/3 of total consumption.

Alloys and some features of tin

The use of tin alloys is common as antifriction materials, that is, materials that have a low coefficient of friction, or that can reduce the coefficient of friction of other materials. Using antifriction materials, you can significantly increase the life of mechanisms and machines by reducing friction losses.

Another interesting feature of tin (the so-called white) is its ability to increase its volume by 25.6% when the temperature drops to 13.2°C . In this case, the so-called gray tin is formed. When the temperature reaches -33°C, the metal cracks and becomes powder. If gray and white metal come into contact, “contamination” of the white will occur. The combination of such phenomena is called the “tin plague.”

Various tin-based alloys are used in electrical engineering in the manufacture of electrical capacitors. In capacitors, staniol is actively used: almost pure metal in the form of thin sheets.