Name of screws and self-tapping screws. What are self-tapping screws and what are they?

Screws, screws, bolts - these types of fasteners have been used for a long time, but there are also self-tapping screws. What are they and what are their features? What types of screws are there, and how to choose them?

How does a self-tapping screw differ from a screw?

Let's start with definitions. The screw is fastener with external thread applied to the rod. When joining parts, the external thread of the screw is aligned with the internal thread of the hole in the part or parts. So you need to pre-drill a hole to install the screw. A screw differs from a screw in that it has a smooth narrowing at the end and sparser thread turns.

What is the difference between a self-tapping screw and a screw: thread and material

Now pay attention. Self-tapping screw is short for self-tapping screw. It differs in that installation does not require availability in advance. drilled hole. When screwed in, it cuts the required grooves itself. Hence the term - self-tapping. And so that the self-tapping screw can “bite” into the material itself, its thread is triangular, with sharp edges and, as a rule, “deeper”. So, a self-tapping screw is a type of screw that itself drills a hole in the material as it is tightened.

A self-tapping screw is a screw that drills a hole for itself

If we talk about the difference between self-tapping screws and screws, then the self-tapping screw has a more elongated and sharper edge. With this shape it is easier to “bite into” the material. To install self-tapping screws, a screwdriver is usually used, which allows you to do a large amount of work, unlike using a conventional screwdriver. Overcoming the resistance of the material when cutting a hole is not easy.

Types of self-tapping screws

Self-tapping screws are divided by area of ​​application. They are universal, for wood and metal. These are the three main large groups. There are even more highly specialized ones - for concrete, drywall (gypsum plasterboard), etc. There are separate groups for window profile and roofing materials.

However, keep in mind that when they talk about metal screws, they mean sheet metal or profiles made from it. And then, in sheets of large thickness, holes are often pre-drilled. This makes it easier and faster to install fasteners, especially if they are not of good quality.

There are many types of self-tapping screws. So which ones should you choose?

Moreover, holes are often drilled in wood for self-tapping screws. In dense wood - such as oak - this is an almost immutable rule. The density of such wood is high and otherwise the process is underway too slow. In soft wood, holes for installing self-tapping screws are drilled for another reason - to prevent the wood from cracking. When the screws are placed almost on the edge, this is possible. So they are insured. In any case, the diameter of the hole for installing the self-tapping screw should be 1-2 mm less than the diameter of the fastener. Only under this condition will it be easy to install and the strength of the connection will be normal.

There are also universal screws. But this does not mean that they are “for everything.” This means that they are optimal when it comes to joining wood and metal. And for metal-to-metal, wood-to-wood connections, it’s better to take your own narrow-profile fasteners.

For wood and metal - the difference

What is the difference between self-tapping screws for wood and metal? First of all, different thread pitches. For installation in wood, the carving is rarer. This is quite enough to gain a foothold in the fibrous structure. A self-tapping screw for metal has denser threads. Another difference is the metal used to make the fasteners.

What is the difference between self-tapping screws for wood and metal. The first thing that catches your eye is the density of the thread. The second is the diameter of the pin, the third is the height of the thread profile

Self-tapping screws for metal can also have not just a narrowing with applied threads, but additional planes - a drill. Such fasteners can drill holes in sheet metal up to 5 mm thick. To prevent the edge of the screw from sliding on the surface of the metal (and wood too), the installation point is “capped.” Using a punch and hammer, leave a small dent. It is not necessary to pierce the metal. It is enough that the self-tapping screw drops into the recess.

Metal and processing method

Self-tapping screws are made of carbon steel, stainless and brass. In the vast majority of cases, we use carbon steel self-tapping screws. They are not as expensive as stainless steel, but quite durable if chosen correctly. However, steel screws can be different colors: white, yellow and black. They get color after processing. Black ones are obtained by oxidation and phosphating, yellow ones are obtained by anodizing, and white ones are usually galvanized. There are also yellow galvanized ones.

It is also necessary to keep in mind the method of metal processing

What color screws should I choose? It depends on what material. If for wood, the best choice- anodized. These are yellow ones. Yes, they are much more expensive than black ones. But black oxidized ones rust and then leave streaks on the wood. For metal, this is not critical, since usually the joints are painted over so that they do not rust. But there is one more point: black oxidized screws can be brittle. If you twist it during installation, the head may fly off. Not only can this happen during installation, but it also happens under load. For example, when the flooring was screwed to the joists using black oxidized self-tapping screws. Boards are known to bend and dry out. And this leads to increased loads on the fasteners. And the heads of black screws often fly off. This can be noticed when the floor is rebuilt. And also because some boards begin to bend or sway and creak more strongly. The caps broke off and the fasteners did not hold.

To install metal sheet material It makes sense to take galvanized screws. There will be no conflict of coatings and chemical reactions. In this case, they usually take white ones. Yellow ones are used for aesthetic reasons - during installation door hinges, locks, handles and other similar fittings yellow color.

Types of self-tapping screws: head and slot

Self-tapping screws are also divided by head type. There are many types, but it is worth remembering that there are secret, semi-secret and protruding (hemispherical, semi-cylindrical, etc.). Also available with hex heads. They are used to install roofing material, polycarbonate, fastening materials to fences, covering frames. In general, where rigid fixation is important. Self-tapping screws with hexagonal heads are usually equipped with sealing washers and rubber gaskets.

Types of self-tapping screw heads

Self-tapping screws with countersunk heads are hidden in the wood during installation. In this case, there is no need to pre-drill holes of a larger diameter for the cap. To make the hat fit like clockwork, take countersunk heads with notches.

Types of slots on self-tapping screws. It makes sense to take those for which you have an instrument

The heads have a recess for the tool - this is the slot. We select this parameter based on the available tool or bit. You can, of course, buy them - bits - but you should think about this in advance. And then purchase fasteners and bits. If we talk about which spline is better, then Torx is currently considered the best, since it transmits torque best. This is important when working with hard material.

Selecting the length of screws

To select the length of the self-tapping screw, there are several rules that are used in different situations. When uniting/connecting two not very massive parts, they work following rules selection:

If some thin part is attached to a massive base, a different rule applies. Then the length of the fastener should be 2-2.5 times longer than the attached part. This is how you need to select the length of the screw if you are attaching something to a wall, say, or to concrete floor. In this case, to fasten the same 28 mm board to the wall, the length of the fastener is 56-70 mm. That's the difference.

Self-tapping screw sizes: most applicable options

How to choose the length of the screws should be clear. Now about what they generally are. The situation here is confusing. Neither screws nor self-tapping screws have a common standard. There are several standards of “worn out” years of manufacture, which specify the dimensions of certain types of self-tapping screws.

• GOST 1145-80. Countersunk self-tapping screws.
• GOST 1144-80. Round head screws.
• GOST 1146-80. Screws with a semi-countersunk head.

The situation today is that each manufacturer produces its own “lines”. They focus, of course, on demand. Well, the parameters of the heads are usually made in accordance with one or another GOST. This will at least somehow stabilize the situation. Sometimes the assortment - diameters and lengths are also made according to the standard. In this case, in the description of the screws, the diameters in which they are generally produced are indicated, and then there is a postscript: it corresponds to such and such GOST. This means that the heads comply with the specified standard, and also that the assortment corresponds.

Diameters and lengths of self-tapping screws with a countersunk head GOST 1145-80 and a semi-countersunk head GOST 1146-80

How then do you choose self-tapping screws according to length and diameter? Calculate/determine the length that is needed and determine the type of head. Then they look at the diameters and make the final choice. Let’s say right away that for wood the principle “thicker is better” does not work. This can be applied to metal. For wood, thinner ones are better, but with good carving and made of good metal. This is the ideal option.

If the manufacturer has his own parameters for the screws, they are indicated in the description

But this is not enough. The store usually offers up to a dozen options of the same size, but different manufacturers. And if it’s more or less easy to decide on the metal and type of processing, then choosing which brand to take is difficult. There are, of course, proven ones, but they are expensive. Although, if you take cheap ones, 30-50% may be wasted. What kind of marriage? Either they bend or the caps fly off. This is not always, but often. If you are “lucky” to run into such fasteners, it turns out that it would not be more expensive to buy “expensive” ones. Well, or not much more expensive.

Lengths and diameters of self-tapping screws with a semicircular head according to GOST 1144-80

Now compare the two tables. They are compiled according to different GOSTs. As you can see, the diameters and lengths are the same. This is what makes life easier. If during the production of fasteners we adhered to the standard in terms of the diameter/length ratio, then everything is simple. If not, then the manufacturer includes a table with dimensions in the description of the screws (as in the figure above).

You should not use metal or universal screws to fasten wood. Universal ones are good when you need to twist wood and metal. And when twisting two pieces of wood, they work worse. In the sense that specialized fasteners will hold the wood better. That is, we consider only wood screws. Believe me, there will be plenty to choose from.

Wood screws are better yellow (yes, expensive) or white (a little cheaper)

As already said, wood screws have a rarer thread with a higher profile (the grooves between the turns are deeper). They are used not only for wood, but also for all types of sheet materials: gypsum fiber board, plywood, OSB (OSB), fiberboard and chipboard. Now about when which ones work better.

Carving and other bells and whistles

First you need to choose the type of hat. Countersunk or with a press washer, cylindrical, hemispherical - choose based on what kind of connection you need to make. It is also recommended to choose a TORX type slot, as it best transmits torque from the power tool. Next in order.

Are these bells and whistles necessary or is it a waste of money? As for the incomplete carving, this is not news. One part “fits” onto another much more tightly. And try the rest. Only from your own experience will you understand whether it works or not, and what exactly suits you best.

AND practical advice by choice of wood screws. It is important that the thread goes straight from the very tip. If the first turn is too far or the tip is blunt, don’t take it. It will be pure torment, not work.

Selection of screws for metal

There are more types of self-tapping screws for metal, so it’s time to figure it out. They are definitely not made of brass - the metal is too soft. Metal screws are made from carbon and of stainless steel. All types of heads are present, almost all splines are also available. There are two types of tips - with a sharp end and a drill. They are also divided by area of ​​application - for interior spaces and for the street. They differ in the thickness of the protective layer. For the street, the coating should be thicker. Let's look at the most common types of metal screws.

The most popular types of screws for metal

Self-tapping screws with press washer (seeds)

They differ in their head - it is wide and flat. A roller is formed along its edge, which presses the parts. This type of hardware is used not only for fastening sheet metal and products made from it (for example, assembling a frame for drywall). It can also be used if you need to secure plastic, plywood or fiberboard to wooden blocks, metal or wooden frame. The flat and wide head presses materials well at the joint.

This is what self-tapping screws with a press washer look like

If you look closely at the fastener head in the photo on the right, you will see that the part has a rounded and almost flat shape. By the way, most of them are in stores and on the market. But it is not the best option this fastener, although cheap. There are very few worthy products of this type. Often the slot is small, untreated metal that breaks or bends. But the most important thing is that even white galvanized screws have a very thin layer of galvanization - 3 microns. It quickly deteriorates and the metal begins to rust.

Self-tapping screws with a press washer are produced in only one diameter - 4.2 mm, but the length can be different

If you look at the more expensive metal screws with a press washer (pictured on the left), they have a trapezoidal head. It is taller, which allows you to make a deeper slot. They are also called “reinforced”. The quality of such fasteners is much higher. A deeper spline ensures better torque transmission. This makes it possible, even without increasing the size of the screw, to tighten the parts more tightly. Due to what? Due to the fact that the reinforced structure can withstand greater torque.

The variety of sizes of screws for metal with a press washer is not encouraging. Usually there is only a diameter of 4.2 mm, and the length can be 13, 16, 19, 25, 32, 38, 41, 50, 57, 75 mm. The weight of the package depends on the number of pieces. It can also be one of the criteria for assessing quality. In any case, the density of the metal and how accurately the dimensions are maintained. Because very often the rod is made not 4.2 mm, but 3.8-4.0 m, also in length. And the thickness of the cap is smaller. In general, pay attention to the weight of the screws.

Self-tapping screws for gypsum plasterboard profiles

These are small black hardware. There is no variety in sizes. There is one diameter - 3.5 mm and two possible lengths - 9.5 and 11 mm. Because of their small size they are called “bugs”. They are made of steel with zinc coating or phosphating. The head is a truncated cone, with a cross-shaped slot. A notch may be applied to the underside of the head. It serves for braking - it begins to cling to the relief on the screw, which turns off the rotation of the screwdriver.

Appearance and drawing

There is a pointed screw and there is one with a screw. Despite their small size, they drill metal up to 0.9 mm thick, and fasteners with a drill - up to 2.0 mm. But this is if they are of normal quality. Please note that this fastener is designed for indoor use. It starts to rust quickly outdoors, so don't use it outside.

Black self-tapping screws for attaching gypsum boards to the frame

The frame for drywall is assembled using “bugs” or self-tapping screws with press washers. The sheets themselves are attached to the frame using black self-tapping screws with a countersunk head and a sharp end. They are made of phosphated steel, and also galvanized. Actually, these are screws for wood or metal. Which ones to take to attach gypsum boards? Depends on what kind of frame was assembled. For wooden bars use wood, for profiles use metal.

This is what the self-tapping screws for attaching drywall sheets to the frame look like

If you are sheathing a regular living space with plasterboard, black phosphated self-tapping screws are a good choice. If the frame is assembled in the bathroom, kitchen, toilet, it is better to take galvanized ones. At high humidity The black ones rust quickly, then the heads fly off.

The most common sizes of self-tapping screws for drywall, which are attached to wooden sheathing

What are the sizes of self-tapping screws for attaching drywall? Optimal diameters are 3.8, 4.0 and 4.2 mm. Length can be 16, 19, 25, 32, 35, 41. 45, 51, 55, 61, 65, 70, etc. up to 100 mm. What length of self-tapping screw is needed to attach a sheet of plasterboard to the profile? Use it universal rule: Double the length of the attached material. If you are fastening plasterboard with a thickness of 12 mm, then the self-tapping screw is no shorter than 25 mm. Can it be longer? It's possible, but why?

Roofing screws

This is a type of fastener for outdoor use. This means that the protective layer is thicker. Roofing screws can be easily identified by appearance. They have a hex head and a sealing washer. The washer can be rubber or silicone. Silicone is much more durable, but also more expensive. Good rubber, by the way, can also not crack for decades. It’s just difficult to determine whether it’s good or not.

Roofing screws come in different types and are designed for fastening different materials to frames of different rigidity. There are these types of roofing screws:

Types of self-tapping screws for roofing and their area of ​​use

• Pointed. Designed for fastening soft material to wooden sheathing.
• With short screw. This type is for fixing metal sheet material to wood.
• With a long screw. This is for metal-to-metal fixation. Most often used for attaching corrugated sheets to the fence frame.

Length and diameter of roofing screws of different types

Roofing screws are made of galvanized steel. And it’s better if galvanizing is done. This coating is more durable. Sometimes paint is also applied over galvanization. Color - matching with coating. The washers are made either galvanized or from aluminum alloy. The washer was said to have a rubber or silicone seal. Rubber is better than EPDM, it does not lose elasticity even in the open air for a long time. The running dimensions of roofing screws are given in the table.

In this article we will talk about the types and characteristics of self-tapping screws and help you decide on the choice of fasteners, taking into account the type of material being fastened. What is the difference between self-tapping screws, types of threads and slots?

Currently, there are a large number of fasteners on sale - anchors, dowels, etc., however use of self-tapping screws still relevant. The main advantage of self-tapping screws is that there is no need to pre-drill the surfaces to be fastened; using a screwdriver or screwdriver, the self-tapping screw will drill its own path. This results in a reliable fastening.

Self-tapping screws - technical specifications

Self-tapping screws are a fastening material consisting of a head with a slot and a threaded rod, as well as a tip of a certain shape. They are manufactured using standard quality structural carbon steel, as well as improved quality low alloy steel and non-ferrous alloys (copper, brass, zinc and aluminum). In addition, some types of self-tapping screws are coated with anti-corrosion compounds, usually zinc. We will talk about the differences between self-tapping screws below.

Types of self-tapping screw heads

High-quality self-tapping screws are distinguished by types of heads:

A self-tapping screw with a hex head can be produced either with a molded press washer or with a stacked washer. The hexagon is screwed in with a regular key;

With a countersunk head, thanks to which, after screwing in, the fastener is completely recessed into the surface;

A self-tapping screw with a hemispherical head, which, as a rule, remains on the surface, but if necessary, it is recessed;

For fastening fragile materials Fasteners with a hemispherical head equipped with a press washer are used, as well as a head with an enlarged press washer.

What types of slots are there for self-tapping screws?

The slots on self-tapping screws are necessary to transmit torque from a screwdriver or screwdriver to the fastener itself. There are quite a few of them, and we will note only the most common ones.

Straight spline. Previously it was quite popular, but it Lately almost completely embossed the cross slot.

Phillips slot. The Phillips product was to the taste of the consumer, as it significantly simplified the process of screwing in a self-tapping screw.

Pozidrive Phillips. Fasteners with such splines allow more efficient transmission of force from the tool. This was made possible due to the smaller apex angle and additional antennae. However, this requires more precise centering of the screwdriver or bit in the slot, which slows down the work somewhat.

Torx spline. It holds a record for efficient torque transmission, but requires careful alignment of the spline with the tool, so it is not suitable for screwing large quantity self-tapping screws Typically, fasteners with such a slot are used for screwing frames, dowels and facade elements.

Square splines, And internal hexagon splines are practically not used, except perhaps only in the furniture industry.

Even less commonly used are special splines, or, as they are called differently, “secret” splines.

The thread is also varied, and which screws to use depends on the type of material being fastened:

Large carving. Self-tapping screws with a rare thread pitch allow you to fasten soft materials - gypsum, asbestos, plastic and soft wood. The diameters of such screws are from 3.5 to 5 mm, length - from 16 mm to 150 mm;

Medium thread. These are universal self-tapping screws, suitable for almost all types of fastened materials. Diameters of medium self-tapping screws - from 3 mm to 6 mm, length - from 12 mm to 220 mm;

Medium thread, herringbone profile. Designed for fastening to concrete and brick surfaces, driven into a dowel. The diameters of the screws are from 3 mm to 8 mm, the length is from 12 mm to 200 mm;

Frequent carving in two passes. Self-tapping screws designed for fastening to metal sheets up to 0.9 mm thick have this type of thread. Available with or without a drill at the tip (in this case, pre-drilling is required). The diameters of such screws are from 3 mm to 8 mm, length - from 12 mm to 200 mm;

Asymmetrical thread. This type of thread is intended for self-tapping screws used in furniture production, used for fastening furniture elements made of wood, plywood or chipboard. Pre-drilling is required, screw diameters are 5 mm and 7.5 mm, lengths are from 40 mm to 70 mm;

Variable knurled thread. The purpose of construction screws with such threads is to fasten to concrete or brick surfaces without a dowel. The diameter of the self-tapping screw is 7.5 mm, length from 70 mm to 200 mm.

Self-tapping screws appeared in Russia in the sixties of the last century. Since then, they have been changed, refined and classified more than once. Some of the features of this fastener will be discussed.

Self-tapping screws - what do you need to know about these hardware?

A classic self-tapping screw is a fastener in the form of a metal rod with a thread applied to it. During operation, it is screwed into the attached part, forming a thread in it and attracting it. Unlike classic screws and screws, the thread does not completely cover the self-tapping screw, and the self-tapping screw itself is made of more durable material and in the future it is also hardened. Today, fasteners of this type are used in almost all areas of life: household, construction, repair, production, making souvenirs, decorative fakes and even paintings.

There are plenty of new materials on the construction market, ranging from sibit, thermoblocks and ending with sandwich panels. But in Russia, such building material as wood is traditionally popular. Products made from it traditionally occupy the top lines of the rating in the list of construction and ornamental materials. It is not surprising that wood screws are also in demand.

As you can see, this is a black fastener in the form of a metal rod with a thread applied to it that does not reach the cap. In operation, the hardware is screwed into the workpiece, cutting a thread and tightening it.

Hardware (short for “metal products”) is a generalized name for all metal products, including self-tapping screws.

Key Difference self-tapping screws intended for fastening wooden products, – wide thread pitch. Hardware intended for working with metal has smaller threads. The wide thread breaks the fibers, providing reliable fixation of the workpieces. However, when working with hard wood, it is recommended to use fasteners with fine threads (used for fastening metal products). In addition, self-tapping screws exist and are widely used for working with plastic, MDF, chipboard, etc.

In hardware stores there are self-tapping screws for any purpose. But such diversity can confuse a novice master. Let's try to help him. On the price tag (or in the price list), the name of the product is usually given in this format - 3x70 mm. The first number 3 indicates the diameter of the thread (given in mm), and 70 is the length of the self-tapping screw from its tip to the end of the head.

However, many stores provide their windows with visual information. But if it’s not there, you can always use a special table:

As you can see, this table helps you make a choice. By the way, the length of the screws is not mentioned intentionally - this parameter is determined based on specific tasks. For example, fasteners 7 cm long should not be used to connect two parts with a total thickness of 3 cm.

Classification of self-tapping screws for wood - let’s ease the pain of choice

A great variety of self-tapping screws have been invented: for metal, for wood, for roofing, for working with drywall, gypsum plasterboard, plastic, etc. But even in one subgroup they may differ. For example, there are several types of hardware only:

• Black oxidized - designed for use in light conditions.
• Yellow and white. They differ from their black counterparts in having a more frequent thread, its angle of inclination (45 degrees) and protective coating, giving them a yellowish or white color. Used for working with hardwood or chipboard.
• Wood grouse self-tapping screws - they are distinguished by more solid dimensions and a turnkey head - hexagon. As a rule, they are used when assembling furniture.

It is believed that the oxidized coating of the black self-tapping screw imposes some restrictions on its use - only in dry places. Yellow and white screws, according to manufacturers, are more attractive in appearance, and the zinc coating provides reliable protection. In fact, black self-tapping screws are more popular among craftsmen. And it’s not just about the price (yellow or white fasteners are 20 percent more expensive).

As practice shows, yellow self-tapping screws are not much longer than black ones in terms of service life. And finer threads do not always provide reliable fixation of workpieces. But if the design of the product is of primary importance, it is better to use yellow or white fasteners - their appearance is more aesthetic.

We work with fasteners - nuances of preparation, necessary tools

The heads of hardware for wood have slots for a Phillips screwdriver. The exception is self-tapping screws, they are tightened with hexagons or keys. But in everyday life, they mostly work with the more familiar yellow or black self-tapping screws. They can be fixed in the surface of the product or wooden wall using conventional Phillips screwdriver. But only when there are few of them. For large volumes, get the appropriate tool - a screwdriver or electric drill with a set of bits and attachments.

The work begins with markings: in the places where you plan to screw in the screws, make deep punctures with an awl. This is a precautionary measure that will prevent you from making a mistake in the place where the screw is screwed in and will not allow it to slip off.

Another nuance is the effort applied. After installing the screw in place, do not give the power tool high speeds - this can tear off the slots in the hardware head, or even the head itself. The first turns are made carefully until the self-tapping screw is secured in the material.

The tree is attached only with special fasteners. This is a postulate and an axiom. But even in this case, there are tricks that allow you to get the best result. The main one is the use of a drill. That is, before screwing in the screw, drill a hole for it. Hardwood Drill Diameter equal to diameter self-tapping screw, for fiberboard - a millimeter less, for soft wood and chipboard - 3 millimeters less. Pre-drilling reduces the risk of splitting the wood, but for thick soft slats or boards you can do without it.

Although special fasteners have been invented for working with drywall, the usual black oxidized screws are often used for these purposes. Considering the fragility of this finishing material, we simply have to mention some of the features of the work. Let's start with the fact that for this coating optimal distance between hardware, a step of 0.7 meters is considered. And power tools are used with caution.

At the beginning of work, the screwdriver can be used at full power, but after screwing in the fasteners halfway, begin to reduce the speed. It is advisable to use products with a conical head. This will allow it to be recessed 1 mm below the cardboard level. Please note, it is reinforcing cardboard, not plaster. This will provide the structure with additional strength. But if in inopportune moment“the hand trembled” and the cardboard tore, the place of the defect needs to be puttied, and the fasteners must be moved 5–10 cm.

In general, when working with decorative panels And finishing materials, attached to the frame, the choice of screws depends on its type. That is, if drywall is “sewn” onto a wooden sheathing, wood fasteners are used, and if the base is assembled from a metal profile, metal screws are used. The requirement for the latter is a small hat that can be hidden during subsequent finishing.

The abundance of shiny fasteners on the shelves of hardware stores pleases the eye, but makes every person not professionally associated with the sale of fastening equipment awkwardly hang around the display window. The purpose of half the screws is unclear, and it’s awkward to ask the seller... Let’s try to understand the variety of screws - self-tapping screws presented on the modern market. After 5 minutes, you will be surprised to find that everything is much simpler than it seems.

The screw is a self-tapping screw. Where does the confusion come from?

What is the difference between a screw and a self-tapping screw? I suggest you look into GOST 27017-86 which gives following definition screw:

A screw is a fastener in the form of a rod with an external special thread, a threaded conical end and a head at the other end, forming a thread in the hole of the wooden or plastic product being connected.

As follows from a document dated 1986, the use of this type of fastener involved pre-drilling a hole and limited the material of the fastened elements to wood or plastic. For this type of screws, brass, low-carbon steel (St1, St2, St3, 10kp) or corrosion-resistant steel without galvanic coating are used. As a fastener, the classic screw is not very popular, but even today it is still found as a cheap alternative to self-tapping screws.

The self-tapping screw is a new stage in the evolution of fasteners. Formally, it corresponds to the definition from GOST, which we cited above, but has significant design differences (shape of slot, coil, thread and tip) and is made of high-quality steels with corrosion-resistant coatings.

As the name suggests, the self-tapping screw can cut threads on its own and is used without pre-drilling holes. Self-tapping screws can handle not only wood and plastic, but also metals, concrete, brick, etc. Given the variety of fasteners, it is useful to know their sizes and classification. Below are convenient tables for each type.

Transcript example

Screw 1 - 4×25 GOST 1145-80

Standardized labeling looks like this, but in practice everything is much simpler. On the box that you take from the shelf, only the purpose of the screws and their sizes will be written.

Standard sizes of self-tapping screws

The size of a self-tapping screw is determined by only two quantities: length and diameter.

Universal screws

They are usually made with incomplete threads. Used for wood, chipboard, etc. soft materials. Self-tapping properties are low. By standards GOST 1144-80, 1145-80 , 1146-80 Available in diameters 1.6, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0 mm and lengths 13, 16, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120 mm.

Self-tapping screws for wood, chipboard, fiberboard, plastics

One of the most common self-tapping screws. Used for installation in dowels. Available with galvanized coating ( white) or galvanized and chromate passivated (yellow), sometimes treated with phosphate.

Wood screw with hexagonal head

DIN 571 and GOST 11473-75. Designed for fastening joists, slats and other tasks that require reinforced fixation. As a rule, it is produced galvanized.

Screws for fastening to metals

Screws according to DIN 7981, DIN 7982, DIN 7982

Visually similar to universal ones, but differ in materials of manufacture, entry angle and thread profile angle (up to 60 degrees).

Screws according to DIN 7504

Structurally almost completely identical to pointed screws for metal DIN 7981, 7982 , 7983 (see table above). The key difference is the tip that performs the function of a drill.

Self-tapping screws for sheet metal and metal-based products

Self-tapping screws with press washer

They are found on sale with both a drill (for metal up to 2mm thick) and a sharp tip (designed for metal up to 0.9mm). Standard diameters 4.2 (4.0) mm and length - 13, 14, 16,
18, 19, 22, 25, 32, 41, 51 mm.

Self-tapping screw with a semi-cylindrical head (“bug”)

Similar to its predecessor, it can be either sharp or with a drill. There is no size guide for this self-tapping screw and it comes in only one size option:

With sharp tip - 3.5 x 11

With drill tip - 3.8 x 11

Hex head screws

Designed to work with sheet metal without preliminary preparation of the hole. Provide reinforced fastening. From one manufacturer to another, variations in product sizes for a given segment of fasteners are possible. The tables below show the most popular ones.

With a sharp tip.

For metal sheets up to 0.9 mm.

With drill (DIN 7504-K)

For metal of large thickness (5mm or more). The length of the drill tip determines the swing. sheet metal thickness.

Self-tapping screws for drywall

Manufactured with a countersunk conical reduced head, a Phillips slot, a double-start variable thread and a sharp tip. Dimensions of fasteners for mounting on wooden frame or a metal profile with a thickness of less than 0.9 looks like this: Ø 3.9 mm with lengths 19, 25, 30, 45 mm.

Self-tapping screws for fastening slabs and sheets of chipboard, fiberboard, plywood

As a rule, these are galvanized screws (FLUGEL) measuring 5.0 x 36

Available with a countersunk conical head and notches for countersinking a countersunk hole ( DIN 7504P) with dimensions:

Roofing screws

When installing the roof, it is advisable to use standard galvanized self-tapping screws. They are resistant to corrosion. The size chart looks like this:

Issued roofing screws with painted heads. The paint provides additional protection against exposure external factors. And they do not spoil the exterior of the roof, since they are “selected” by color.

Screws and self-tapping screws for special purposes

Confirmations

Confirmat or “euro-screw” is a separate category of fasteners. It is designed for the assembly of furniture panels. It is made with various protective and decorative coatings (usually galvanized). The thread pitch is rare. The task is to pull the parts together. The head has characteristic difference. A special hexagon is required for screwing.

Screws for concrete

Screwed into a pre-drilled hole. It is not recommended to use a hammer drill. Hence the complexity of the process. Before screwing you need to drip machine oil- this will make the procedure a little easier. A type of fastener that is called “forever”. Withstand high loads (up to 100 kgf). Available in: Ø 7.5 mm. Length: 50, 70 (72), 80, 90, 100, 120, 130, 140, 150, 160,180, 200,... mm.

Window screws

No hole preparation is required. They work as “amplifiers” of windows and have the following dimensions: Ø 3.9 mm, lengths: 13, 16, 19, 22, 25, 32, 35, 40 (38), 45 mm.

Frame screws

Large screws with high strength. They are screwed into the dowel and sometimes come complete with it.

Adjustment screws

A characteristic feature is the second thread. The first thread (usually smaller) is necessary for fastening to the base, the second is used for mounting the substructure.

Popular screws are ∅6 mm screws and lengths: 60, 70, 80, 90, 100, 110, 120, 130, 145 mm.

Scaffolding screws

Screws-nails

Screws for hangers

They are very convenient in everyday life, for example, we have had a children’s swing hanging on such fasteners for several years in the corridor of a city apartment. Time to install and remove is literally 1 second! Single standard there is no size specification for this element and each production creates a size range at its own discretion.

Cheat sheet for the home handyman

The following tables will help you navigate when choosing the necessary fasteners.

We distinguish the product by the type of thread

Self-tapping screws vary in the frequency of turns. The small pitch allows the fasteners to be used for metal parts. Screws with rare threads are designed for materials with low density. This includes: asbestos, gypsum, plastic, etc. Self-tapping screws can be classified according to their appearance as follows:

It's all in the hat

Based on the shape of the cap, you can determine the intended purpose of the self-tapping screw. The relationship between these parameters is shown in the table:

The fact that a lot of effort was spent on screwing it in does not indicate the titanic torment that will have to be endured if the need arises to unscrew the screw. Therefore, every time a “forever” method is recommended, it is worth thinking about the feasibility. Manufacturers offer a variety of self-tapping screws, differing in the metal from which they are made. The cost also varies. In order not to overpay, you need to give an objective assessment of the load to which the fastening unit will be subjected. If we are talking about a “carnation” for a painting on wooden wall, it makes no sense to spend money on expensive screws.

The screwing tool can be used both manually and electrically. Often a screwdriver is sufficient. This method will not allow achieving high labor productivity if we are talking about professional work and large volumes of fasteners. A familiar screwdriver is optimal for the job.

Slit - smiley :) Incredible but true

The Japanese plant Komuro Seisakusho released a batch of fasteners with a non-standard slot in the shape of a smiley face. The author of this funny idea is designer Yuma Kano. Unfortunately, the new product has not yet been presented on the domestic market.

We hope that now you have once and for all figured out the issue of the purpose and size of fasteners. We will be grateful for recommendations, criticism and detected inaccuracies.

Among the wide variety of fasteners, it is difficult not to get confused. Self-tapping screws and self-tapping screws are fasteners consisting of a rod with a sharp thread and a head. They are different in length, thickness, material, shape, purpose. For a certain type of work, specific screws are used. There are, of course, universal fasteners, but they are not always suitable and will securely secure this or that material. Let's take a closer look at their purpose.

What is the difference between a self-tapping screw and a screw? The main difference is in the carving. The self-tapping screw barrel consists entirely of a threaded part or has a smooth part that is shorter than the threaded part. The tip of the self-tapping screw is sharper than the end of the screw. Screws are made from soft species steel, self-tapping screws - hard.

Modern self-tapping screws are made from special hardened steel and are protected from corrosion. Due to surface treatment, hardware is produced in different colors. Most often they are galvanized (yellow and silver color) or black (oxidized or phosphated).

According to the area of ​​application, self-tapping screws differ as follows:

For wood material

For drywall

For metal sheets

For sandwich panels

For window profiles

Self-tapping screws for wood and plastic

They differ from all others by their rare thread pitch. They look like a trunk with sparse carvings and a countersunk head; the head is easily recessed into the wood and does not interfere with further surface processing of the material. The rare step on the screw is made with structure in mind wooden materials to avoid wood crumbling and more secure fastening.

Used as a fastener for drywall to wooden sheathing, for fastening wooden elements each other without pre-drilling holes. Black screws are most often used for this.

Furniture self-tapping screws (confirmat, euroscrew)

Used in the production and assembly of furniture. Made in the form of a metal rod with a rare and high thread, and a blunt end. The cap is flat in shape, there is a thickening near the cap. During installation, as a rule, a 6-diameter hexagon wrench is used. Requires pre-drilling. The heads can be covered with decorative ones.

Self-tapping screws for window profiles

They look like a rod with a drill at the end or a sharp tip and a countersunk head. Mainly used in production plastic windows for panels to metal profiles. Material - steel, coating - white and yellow zinc.

Screw for concrete

Sometimes called a dowel. They are used to attach parts to a solid base. The most common dowels are divided into two types:

With cylindrical head;

With a hidden head.

They have a special uneven thread along the entire length to create special fastening strength. Pins are used for fastening wooden, aluminum structures to a concrete (brick) base.

Capercaillie screw

A very thick screw, perfect for heavy structures where special strength is needed (slats, beams, bars, etc.). Requires pre-drilling of the hole. Hex head, wrench or hex bit. The thread can be located along the entire length or slightly short of the head. This fastener is often used for installing plumbing fixtures and water heaters. The fastenings are very durable and can withstand fairly high loads. Before screwing, you must first make a hole with a drill.

Once you become familiar with the types of self-tapping screws and their purpose, you can securely fasten any elements together. You can buy self-tapping screws of any type in the Dom online store with delivery or pickup.