Self-tapping screws for wood - the usual fasteners for all occasions. Self-tapping screws and screws What are the yellow self-tapping screws called

This is only half the battle. To complete the task of fastening, it is required to wrap more self-tapping screws, directly into the drilled hole or into the dowels.

Self-tapping screw - a type of fastener, which is a rod with sharp threads and a head designed to transmit torque when screwing while simultaneously cutting threads in the connected elements.

The assortment, for fastening to the wall, self-tapping screws on sale tends to infinity. The task of selecting hardware (from the phrase "metal products") for fastening to the wall seems insoluble. But if you put everything on the shelves, it becomes clear which self-tapping screw is required for each specific case.

Self-tapping screws are made of brass, carbon and stainless steel (metal contains more than 13% chromium). The most widely used self-tapping screws are made of carbon steel with a protective coating. They are the cheapest.

Self-tapping screws made of carbon steel are available with the following types of protective coatings. Oxidized, black - for fastening in rooms with normal humidity. Silver galvanized for indoor and outdoor use. Galvanized, yellow color - for indoor and outdoor use. They have a golden decorative appearance. Looks good on door locks and gold-plated hinges.

Types and types of self-tapping screws

According to the type of thread, self-tapping screws are: with a universal thread, with a rare thread pitch and frequent. Self-tapping screws with a frequent thread pitch are designed for screwing into metal sheets. For example, if you need to hang a heavy picture on a plasterboard wall. Use a powerful magnet to find the place where the profile is located, to which the sheets are screwed, and screw the self-tapping screw through the drywall into the profile. If the self-tapping screw is without a drill at the end, then it is first necessary to drill a hole in the metal with a diameter equal to the inner diameter of the thread of the self-tapping screw.

For fastening sheets of roofing iron, there are special galvanized self-tapping screws of two sizes: 4.8 × 16 and 4.8 × 19 with a hexagonal head. A type of self-tapping screw with a rare thread pitch is designed specifically for screwing into soft materials, such as plastic, plaster, asbestos, wood board and the like. Universal - designed for twisting into any materials. Of course, it is better to use specially designed ones, but any will reliably hold.

List of popular types of self-tapping screws, their purpose and dimensions
The appearance of the screw	Self-tapping thread pitch	Scope of self-tapping screws	Self-tapping screw diameter, mm	A number of lengths of self-tapping screws, mm
	Average	Universal self-tapping screws, designed for all types of fastening, are the most popular	3,0; 3,5; 4,0; 4,5; 5,0; 6,0	12; 16; 20; 25; 30; 35: 40; 45; 50; 60; 70; 80; 90; 100: 120; 140; 160; 180; 200; 220
	Frequent, carving in two sunset	Self-tapping screws for fastening to metal sheets up to 0.9 mm thick without dowel, pre-drilling of the hole is required. self-tapping screws come with a drill on the tip, but are more expensive
	Rare	Self-tapping screws for fastening to soft materials without dowels - soft woods, plastic, gypsum, asbestos, and the like	3,5; 4,0; 4,5; 5,0	16; 20; 25; 30; 35: 40; 45; 50; 55; 60; 70; 75; 90; 100: 125; 150
	Average, herringbone profile	Self-tapping screws for fastening to concrete or brick walls by driving into a dowel	3,0; 3,5; 4,0; 4,5; 5,0; 6,0; 8,0	12; 16; 20; 25; 30; 35: 40; 45; 50; 60; 70; 80; 90; 100: 120; 140; 160; 180; 200
	Asymmetric	Self-tapping screws for fastening elements of modern furniture made of wood, chipboard, plywood, etc. Requires pre-drilling a hole with a diameter of 4.5 or 7 mm respectively	5,0; 7,5	40; 50; 60; 70
	Variable knurled	Self-tapping screws for fastening to concrete or brick walls without dowels (pins), screwed into a hole, 15 mm deeper than the screwed length of the self-tapping screw, 6 mm in diameter	7,5	70; 90; 110: 130; 150; 180; 200

A separate line is worth noting a self-tapping screw - a confirmation specially created for the manufacture of furniture from wood and chipboard. A self-tapping screw of the confirmat type, with a clean surface and a large area of the side surface of the thread, makes it possible to obtain a high-strength and precise connection of elements. The most popular standard size of confirmat is 7×50. Before screwing the confirmation, drilling a hole with a diameter of 4.5 or 7 mm, respectively, is required. The head of the confirmation is made with a hex key.

To hide the head of a twisted self-tapping screw confirmat, decorative plastic buttons are produced - plugs of any color. The protrusion plug is tightly inserted into the hexagonal hole of the confirmat's head and disguises it to match the color of the furniture.

It should be noted that self-tapping screws for concrete, which are screwed without a dowel, directly into the drilled hole. When screwing into porous material and with cavities, drilling holes is not allowed. to make it easier to screw, a little of any machine oil should be injected into the hole before screwing. Used for permanent fastening. I do not use them, as it is difficult to tighten, and even more difficult to unscrew.

There are also self-tapping screws that have a thread profile like a herringbone. They are hammered into the hole at the same time as the dowel with a hammer and are also intended for fastening "forever". Their use is justified, for example, when attaching a baguette to a stretch ceiling or when installing plastic window frames. Their advantage is the speed of installation.

Types and types of heads for self-tapping screws

Head - an extended part of the screw, designed to hold fixed objects and provide torque transmission from the tool to the screw.

Types of heads and their purpose
Appearance	Head type	Purpose
	secret	After installation, the head of the self-tapping screw is completely recessed into the material to be fixed without a protrusion.
	hemispherical	Strongly holds the fixed object due to the sufficiently wide pressing area of the head
	Hemispherical with press washer	With an increased area of the bearing surface of the head and a reduced head height, for fastening sheet materials
	Reduced secret	It has a small bearing surface and a smooth transition from the head to the threaded rod, during installation it is fixed both in the material and in the fastened element, it allows applying much more force during installation than with a standard countersunk head
	Hemispherical with large press washer	With a very large bearing surface and reduced head height, this type of head is designed for clamping soft sheet materials.
	Hexagonal	The oldest head shape, allows you to easily tighten self-tapping screws with great effort with a power tool with a special hex nozzle
	Funnel-shaped countersunk with a thickening along the rod, for a 4 mm hex key	Perfectly masks the connection and allows you to close the head with a decorative plastic button

Self-tapping screws are designated as follows: 3 × 25, where 3 is the outer diameter of the thread (mm), 25 is the length of the self-tapping screw measured from the end of the head to the tip of the rod (mm).

The choice of self-tapping screw depending on the load

Self-tapping screws have a large margin of safety for shearing and bending. The main thing is to securely fasten it to the wall. The more porous the structure of the wall material, the thicker and longer the dowel should be in order to have a large engagement area, and, accordingly, the size of the self-tapping screw. If in doubt about the choice, it is better to choose a larger size self-tapping screw for fastening.

Table for selecting the standard size of a self-tapping screw, depending on the load on one self-tapping screw of the fastened product
Self-tapping screw size depending on the wall material without taking into account the thickness of the fastened product
Ordinary brick	Concrete	Tile	porous concrete	Tree	Drywall
less than 1.0	3×25	3×16	3×16	3×16	3×25	3×16
up to 5.0	3×25	3×20	3×25	3×25	3×30	3×16*
up to 10.0	4×25	4×20	4×25	4×30	3×25	3×16*
up to 20.0	4×50	4×40	4×50	4×70	4×50	4×16*
up to 30.0	5×70	5×50	5×70	5×70	5×50	4×16*
up to 50.0	6×80	6×60	6×80	6×90	6×60	–
up to 75.0	8×100	8×80	8×100	8×140	8×100	–
up to 100.0	10×140	10×100	10×160	10×160	10×120	–

* - the self-tapping screw is screwed in after installing a special dowel for drywall.

Types and types of anchors for concrete

Anchor - a type of finished fastener for fixing heavy products by wedging in the wall. Anker in German means anchor. In practice, this is the same dowel and self-tapping screw, but the difference is that the dowel is made of metal, and the self-tapping screw is a bolt or stud with a metric thread that is screwed into a conical nut. The conical nut, entering the tubular split base of the anchor, pushes it apart, creating a large moment of friction with the wall material. The use of anchors is possible only when fixing in very hard materials, dense brick, concrete and stone. In everyday life, such cases can occur when attaching a heavy chandelier to a concrete ceiling or when installing a large false ceiling. The use of an anchor is justified, for example, for fixing sports equipment in an apartment - rings, wall bars. A children's swing on anchors will also hold securely.

Types of anchors and their purpose
Appearance of anchors	Name of anchors	Purpose of anchors
	Anchor bolt with nut	Simultaneously performs the function of an anchor and a bolt. It is indispensable if you need to fix two parts at once, for example, a corner or a sheet to a concrete wall. This type of anchor is convenient for securely fixing a heavy TV to the wall.
	The drop-in anchor is designed for fixing heavy objects on walls and ceilings made of concrete, not hollow brick, stone.
	Allows you to fasten any product to the stud of the anchor fixed in the wall, with an additional nut
	For hanging stationary products that need to be hung up and removed periodically. For example, a chandelier or streamers between two walls.
	It is used for the same cases as the anchor hook, but prevents accidental slipping of the fixed product
	For fastening to hollow walls
	Universal for fastening wooden and metal frames, wooden boxes to concrete and brick

Anchors are expensive and therefore their use is justified only if there is no alternative method of fastening. The anchor is indispensable, for example, when attaching a heavy chandelier to the ceiling. In practice, in many cases, fastening with an anchor can be replaced by fastening with plastic dowels paired with self-tapping screws, increasing their number.

The abundance of shiny fasteners on the shelves of hardware stores is pleasing to the eye, but makes it awkward to stomp at the window of every person who is not professionally involved in the implementation of fastening equipment. The purpose of half of the screws is not clear, but it’s kind of awkward to ask the seller ... Let's try to understand the variety of screws - self-tapping screws on the modern market. After 5 minutes, you will be surprised to find that everything is much easier than it seems.

Screw - self-tapping screw. Where does the confusion come from

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

Screw - 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 connected wooden or plastic product.

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 steels (St1, St2, St3, 10kp) or corrosion-resistant steels without galvanic coatings are used. As a fastener, the classic screw is not very popular, but today it is still found as a cheap alternative to self-tapping screws.

A 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 (the shape of the slot, coil, thread and tip) and is made of high-quality steels with corrosion-resistant coatings.

As the name suggests, a self-tapping screw can cut threads on its own and is used without pre-drilling holes. A self-tapping screw can handle not only wood and plastic, but 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.

Decryption example

Screw 1 - 4×25 GOST 1145-80

Screw 4 mm diameter, 25 mm long, mild steel, not galvanized

Standardized marking 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 dimensions will be written.

Standard sizes of self-tapping screws - screws

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

Universal screws

They are usually made with incomplete thread. Used for wood, chipboard and other soft materials. Self-cutting properties are low. By standards GOST 1144-80, 1145-80 , 1146-80 are 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.

Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm
2.5	10	3.0	10	3.5	10	4.0	13	5.0	16
	13		13		13		16		20
	16		16		16		18		25
	18		18		18		20		30
	20		20		20		22		35
	22		22		22		25		40
	25		25		25		30		45
			30		30		40		50
					40		45		60
							50		70

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

One of the most common self-tapping screws. Used for dowel mounting. It comes with a galvanized coating (white) or galvanized and chromate passivated (yellow), sometimes treated with phosphate.

Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm
3.0	10	3.5	10	4.0	12	4.5	16	5.0	16	6.0	30
	12		12		16		20		20		40
	16		16		20		25		25		45
	20		20		25		30		30		50
	25		25		30		35		35		60
	30		30		35		40		40		70
	40		35		40		45		45		80
			40		45		50		50		90
			45		50		60		60		100
			50		60		70		70		120
					70		80		80		140
									90		160
									100		180
									120		200

Capercaillie screw with hexagonal head

DIN 571 and GOST 11473-75. Designed for fastening logs, rails and other tasks that require enhanced fixation. Usually galvanized.

Ø, mm	length, mm	Ø mm	length, mm	Ø mm	length, mm	Ø mm	length, mm
6.0	30	8.0	40	10	40	12	100
	40		50		50		120
	50		60		60		140
	60		70		70		160
	70		80		80		180
	80		90		90		200
	100		100		100		230
	120		120		120		250
	160		140		140		280
	180		160		160		300
			180		180
			200		200
					220

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, lead angle and thread profile angle (up to 60 degrees).

Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm
3.5	13	3.9	13	4.2	13	4.8	16	5.5	16	6.3	16
	16		16		16		19		19		19
	19		19		19		22		22		22
	22		22		22		25		25		25
	25		25		25		32		32		32
	32		32		32		38		38		38
	38		38		38		45		45		45
			45		45		50		50		50
			50		50		60		60		60
							70		70		70
							80				80

Screws according to DIN 7504

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

Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm
3.5	13	3.9	13	4.2	13	4.8	16	5.5	22	6.3	22
	16		16		16		19		25		25
	19		19		19		22		32		32
	22		22		22		25		38		38
	25		25		25		32		45		45
			32		32		38		50		50
			38		38		45
							50

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

Self-tapping screws with a press washer

They are found on sale both with a drill (for metal up to 2 mm thick) and a sharp tip (designed for metal up to 0.9 mm). 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")

Similarly to its predecessor, it can be both sharp and with a drill. This self-tapping screw does not have a dimensional ruler and it is found in a single dimensional version:

With a sharp tip - 3.5 x 11

With a drill tip - 3.8 x 11

Self-tapping screws with hexagonal head

Are intended for work with sheet metal without preliminary preparation of an aperture. Provides reinforced fastening. From one manufacturer to another, variations in the dimensions of products in this 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 thick metal (5mm or more). The length of the tip - the drill determines the max. sheet metal thickness.

Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm
4.2	19	4,8;5,0	14	5.5	19	6.3	19
	21		19		25		25
	25		25		32		32
	32		38		38		38
			45		51		45
			51		64		51
			64		76		64
			76				76
							90
							102
							127
							152

Self-tapping screws for drywall

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

Self-tapping screws for fixing boards and sheets of chipboard, fiberboard, plywood

As a rule, these are galvanized screws (FLUGEL) with a size of 5.0 x 36

Meet 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 not susceptible to corrosion. The table with a dimensional ruler looks like this:

Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm	Ø, mm	length, mm
4,80	20	5,50	19 (20)	6,30	19 (20)	7,00	122
	29		25		25		142
	35		32		32		162
	38		38 (40)		38 (40)		177
	50		51 (50)		50
	60		64 (62)		60
	70		76 (78)		70
	80		100		80
			115		90
			130		100
			150		130
			180		150
			235		175
					200
					235

Roofing screws with painted heads are available. The paint creates additional protection against external factors. And they do not spoil the exterior of the roof, as they are "selected" by color.

Screws and self-tapping screws for special purposes

Confirmates

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

Screws for concrete

Screwed into a pre-drilled hole. The use of a perforator is not recommended. Hence the complexity of the process. Before screwing in, you need to drip machine oil - this will make the procedure a little easier. Type of fasteners, which is called "forever". Withstand high loads (up to 100 kgf). There are: Ø 7.5 mm. Length: 50, 70 (72), 80, 90, 100, 120, 130, 140, 150, 160,180, 200,… mm.

Window screws

Hole preparation is not 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 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 serves for mounting the substructure.

Screws are popular screws ∅6 mm and length: 60, 70, 80, 90, 100, 110, 120, 130, 145 mm.

Screws for scaffolding

Nail screws

Screws for hangers

They are very convenient in everyday life, for example, for several years we have been hanging a children's swing on such fasteners in the corridor of a city apartment. Installation and removal time - literally 1 second! There is no single standard for the size of this element, and each production forms a size range at its own discretion.

Cheat sheet for the home master

The following tables will help guide you in choosing the right fastener.

We distinguish the product by type of thread

Self-tapping screws differ in the frequency of turns. A small pitch allows the use of fasteners for metal parts. Screws with sparse threads are designed for materials with low density. This includes: asbestos, gypsum, plastic and so on. In appearance, self-tapping screws can be classified as follows:

thread pitch	Special purpose
	Universal self-tapping screws. Designed for fastening objects from any materials (they are the most common).
Frequent, with thread in double sunset	Designed for attaching to a metal profile up to 0.9 mm thick without the use of dowels (preliminary preparation of the hole is necessary, are available with a drill on the tip, have a high cost).
	Self-tapping screws for attaching parts made of soft materials (wood, gypsum plastic, asbestos, and so on) without the use of dowels.
Medium, with herringbone profile	Self-tapping screws for screwing into reinforced concrete or brick objects of buildings by driving into a dowel.
asymmetrical	Self-tapping screws for fastening elements of modern furniture made of wood, chipboard, plywood, etc. (pre-drilling a hole with a diameter of 4.5 or 7 mm, respectively, is required).
Alternating notched	Self-tapping screws for attaching to reinforced concrete or brick parts of buildings without dowels (pins), (screwed into a hole with a diameter of 6 mm and a depth of 15 mm greater than the immersed part of the self-tapping screw).

It's all about the hat

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

hat type	Features and purpose
secret	After screwing in, the cap is completely recessed into the object to be fixed without a protrusion.
Profile - hemisphere	Strongly holds the attached part due to the increased area of the clamping cap.
Profile - hemisphere with a small press washer	It has a larger area of the working surface of the cap and its underestimated height. It is used when mounting sheet materials.
Small secret	It has a small working area and a gentle transition from the cap to the threaded stem. During installation, it is fixed both in a stationary object and in an attached part. Allows you to apply much more force during the mounting process than in the case of a conventional blind hat.
Profile - a hemisphere with a large press washer	It has a larger working clamping area and a lower head height. Purpose - attachment of sheet parts of low density.
Hexagonal	The head configuration allows you to tighten the screws with less effort, achieving a strong pressing of the fastened objects.
Funnel-like secret with a thickening on the body of the rod	Allows you to mask the connection. Makes it possible to close the hat with a decorative plastic cap. It is screwed in with a specific key (4 mm).

The fact that a lot of effort has been spent on screwing in does not speak of the titanic torments that will have to be experienced if it becomes necessary to unscrew the screw. Therefore, every time the "forever" method is advised, it is worth considering the expediency. Manufacturers offer a variety of self-tapping screws that differ 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 that the fastener assembly will be subjected to. If we are talking about a "carnation" for a picture on a wooden wall, it does not make sense to spend money on expensive screws.

The tool for screwing is used both manual and electric. Often a screwdriver is sufficient. This method will not allow you to achieve high labor productivity when it comes to professional work and large volumes of fasteners. For work, the familiar screwdriver is optimal.

Slot - smile :) Unbelievable, but true

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

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

In the article we will talk about the types and characteristics of self-tapping screws, we will 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 thread and slots.

Currently, there are a large number of fasteners on sale - anchors, dowels, etc., however use of self-tapping screws is 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 a screwdriver, the self-tapping screw will drill its own way. This results in a secure fit.

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 aluminium). In addition, some types of self-tapping screws are coated with anti-corrosion compounds, usually zinc. We will talk about the difference between self-tapping screws below.

Types of self-tapping screws

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

A self-tapping screw with a hexagonal head, produced as a merged press washer, and with a type-setting. 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;

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

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

What are the slots for self-tapping screws

Slots for self-tapping screws and 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.

slotted. It used to be quite popular, but recently it has been almost completely squeezed out by a cross-shaped slot.

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

Pozidrive cross slot. Fasteners with such slots allow more efficient transfer of force from the tool. This was made possible by the smaller apex angle and additional tendrils. However, this requires more accurate centering of the screwdriver or bit in the slot, which slows down the work somewhat.

Torx star slot. It is a record holder for the efficiency of torque transmission, however, it requires careful alignment of the slot with the tool, therefore it is not suitable for screwing in a large number of self-tapping screws. Typically, fasteners with such a slot are used for screwing frames, dowels and facade elements.

Slots are square, and slots with internal hexagon practically not used, except perhaps only in the furniture industry.

Even less often, special slots are used, or, as they are called in a different way, slots “with a secret”.

The thread is also diverse, and which self-tapping 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 woods. The diameters of such self-tapping screws are from 3.5 to 5 mm, the length is 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, hammered into the dowel. Diameters of self-tapping screws from 3 mm to 8 mm, length - from 12 mm to 200 mm;

Frequent carving in two passes. Such a thread has self-tapping screws designed for fastening to metal sheets up to 0.9 mm thick. They are available both with and without a drill on the tip (pre-drilling is required in this case). The diameters of such self-tapping screws are from 3 mm to 8 mm, the length is 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, the diameters of the self-tapping screws are 5 mm and 7.5 mm, the length is from 40 mm to 70 mm;

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

Surely, at least once in your life you had to repair or fasten something yourself. It's no secret that this requires special fittings, and the choice of all kinds of nails, nuts, screws, self-tapping screws and other fasteners in modern hardware stores is very impressive! You stand, you look, and your eyes just widen. Any person, for sure, will be confused in such a store, and so that this does not happen to you, we suggest that you consider in detail such a type of fittings as a self-tapping screw, and figure out how to choose self-tapping screws, what they are and what materials can be used to fasten.

1.What is a self-tapping screw?

self-tapping screw- this is in the form of a rod with an external triangular sharp thread and a head, which, simultaneously with twisting, also cuts a thread in the connected element. Self-tapping screws succeeded almost completely replace, because the connection with their participation is much more reliable, you can fasten it with self-tapping screws, but many other materials, moreover, you do not risk injury during work.

2. Types of self-tapping screws

Material for making screws

Self-tapping coating

Phosphated(black color) self-tapping screws are made of carbon steel with the subsequent processing by phosphates. Used in rooms with high humidity.
oxidized(black color). These self-tapping screws are made of carbon steel with a protective oxide film. Suitable for use in rooms with normal humidity.
Galvanized self-tapping screws are also made of carbon steel, followed by zinc coating. Suitable for both indoor and outdoor use.
Galvanized yellow self-tapping screws differ from the previous ones only in color, they are used mainly for door hinges of decorative gold color, since they are visually less noticeable against their background.
Without cover. Are used for internal works at normal humidity.

Self-tapping screw design

Head (1)

This is the upper part of the screw, with the help of it the torque is carried out. It comes in various forms:

Thread (2)

Tip (3)

Slot (4)

This is a recess of a special shape at the end of the head.

3. Appointment

Universal The self-tapping screw has a countersunk head with a cross slot and a sharp tip. Has a galvanized finish. Can be used both outdoors and indoors, suitable for finishing in wet areas. It is used for fastening wood, plywood, chipboard, sheet metal (with pre-drilling), and other materials. They have a length of 12 to 200 mm, a thread diameter of 3 to 6 mm.
For wood. Wood screws are used to connect plywood, wood, as well as their varieties. Fastening wooden products with self-tapping screws is much stronger than fasteners made with nails, this is due to the presence of threads. Even after a long time spontaneous twisting self-tapping screw never will not happen, as happens with . With proper installation, you will never spoil the material, since the screwing of the self-tapping screw occurs more smoothly, and the sharp tip sets the direction, using a nail you can split the wooden surface, accidentally falling between the fibers. Wood screws come in different sizes, depending on the thickness of the elements to be joined, but they will all have distinctive features: a countersunk or semicircular head with a cross slot, a rare thread pitch and a sharp tip. Basically, black or yellow self-tapping screws are used to fasten wooden elements. Choose such a length of the self-tapping screw so that when twisting two elements, the thread enters the second at least than on ¼ part thickness of wood, then your fastening will be reliable and will be able to withstand loads.
For drywall. can be attached either to special metal profiles or to a wooden frame, depending on the material, they will have differences and self-tapping screws necessary for installation. For fastening to metal profiles, you should choose a self-tapping screw with a frequent thread pitch and a drill at the end, then you do not have to pre-drill, which will significantly reduce installation time. For fastening to a tree, choose a self-tapping screw with a rare thread pitch and a sharp end. Before screwing, stick the sharp end into the drywall to a depth of approximately 1mm. Whatever installation method you choose, drywall screws will have in common: black color, which speaks of thanks to an oxide or phosphate coating, countersunk head, which should sink 1 mm into the sheet, cross slot so that you can tighten the screw not only with a screwdriver, but also with a screwdriver.
For metal profiles and sheet metal. Self-tapping screws for metal have spicy or drilling tip and head press washers, which increases the contact area and provides a tighter pressing of the sheet elements to each other. Advantages of the drill tip is that there is no need for pre-drilling, self-tapping screws are enough easy to screw into a hard metal surface, eliminating the formation of chips or scratches. Self-tapping screws with a drill tip are very strong and can withstand heavy loads, and also have anti-corrosion properties. The thread pitch of such fasteners is rare, which makes it possible to do without the use of special bits or drills. Self-tapping screws with sharp tip have a frequent thread pitch, which allows materials of various densities to be well fastened. They are used mainly for fastening wood to metal, up to 2 mm thick. They also have anti-corrosion properties and high strength. To connect metal products, self-tapping screws with a drill tip and hexagonal head or self-tapping screws with a truncated cone (" fleas”) and a drill tip. "Fleas" are used for a metal thickness of not more than 2 mm. Hexagonal screws are very convenient to tighten with a wrench. To choose the right length self-tapping screw, you need to know the thickness of the part you want to attach to the base and add to this thickness 10 mm. Since for the reliability and strength of fasteners, the self-tapping screw must enter the base to a depth of at least 10 mm. The thread diameters of the self-tapping screw for metal are 3.5 - 5.0 mm in increments of 0.5 mm.
For window profile. There is no separate category of self-tapping screws specifically for, as such, but very often it is necessary to attach the same profile for slopes, or the same handle. Manufacturers of plastic windows, in addition to various accessories, put galvanized self-tapping screws with a countersunk head and a sharp end. But from practice, this type of self-tapping screws is not the most convenient - the sharp end slips off, scratches the plastic, or even scrolls after installation, so experienced installers advise using self-tapping screws with a drill at the end. They are not pulled away when twisted, the window frame does not deteriorate and they are screwed in much easier. The size of the screws is determined by the thickness of what you want to screw to the window. For example, if we are talking about a plastic, thin profile for future slopes, then it is better to use small " fleas» with a drill at the end and a head in the form of a press washer, if the handle is with a hidden head with a cross slot. For reliable fastening, no more than 2-3 mm of thread entry into the window profile is sufficient.
By concrete. In order to screw something to or, it must be borne in mind that the self-tapping screw will be subjected to very heavy loads during installation. For concrete work, choose a self-tapping screw made of galvanized steel with a sharp end and cruciform or six-pointed slotted. The thread diameter must be at least 7.5 mm, the possible length of self-tapping screws for concrete is 50-200 mm. If the base is loose, then pre-drilling can be dispensed with; with a solid base, it is necessary to make a preliminary deep hole.
For corrugated board. To pin and , choose galvanized self-tapping screws, visually similar to screws. The head of such self-tapping screws has hexagonal shape, covered with a polymeric material of various colors, which allows you to choose a self-tapping screw in the same color as the metal tile. Also included with such self-tapping screws is a neoprene washer With a rubber gasket that fits snugly against and prevents moisture from entering the hole. The diameter of such self-tapping screws is from 4.8 to 6.3 mm, and the length is from 190 to 250 mm.

4. How to choose the "right" self-tapping screw

It is not enough to decide on the type of self-tapping screw that is necessary for a certain type of work, it is also necessary among the many options select really quality, durable fasteners that will not let you down at the most crucial moment. Just take a close look at the screw. It must match these simple criteria:

If you see that the self-tapping screws you have chosen meet the above criteria, then you can be sure that you are holding really high-quality fasteners in your hands that will not break during the installation process.

In any type of construction work, various screws or self-tapping screws are used. At the same time, there are a very large number of different modifications, some of which are intended exclusively for wooden structures, while the other helps to connect various metal units, furniture elements or glass products.

Possession of accurate information about what types of self-tapping screws are, their sizes, as well as knowledge and understanding differences materials for their manufacture will allow you to correctly perform the task set for yourself.

After all, no one wants to buy unnecessary thing, ruin the part, and then go and buy everything new. Of course, a negative experience is also very useful, but it can be avoided by studying the necessary materials before buying.

To clarify this issue, it is necessary to study necessary information and instructions.

Basics

First, you should clearly find out for yourself that any screw element will be intended for a specific purpose and have its labeling. Experts pay special attention to the fact that when working with metal, you need to use only metal oxidized self-tapping screws, and with a roof - a roofing screw. Such distinctions are the basis of the basic qualification of this instrument. Mounting screws can vary in size, type and shape of caps, and each has its own price.

If we talk about GOSTs, then for wood screws GOST - 1145−80.

Screws for metal

Despite the fact that the topic of the article is to describe wood screws, first you need to pay a little attention to their counterparts, which are intended for fastening metal. This is necessary so that a person who comes to a hardware store does not rush to buy the first one self-tapping screw, but knew the differences between one and the other.

It will be very difficult to confuse a metal screw with other types of screws if you know how they look. They are made of high-quality metal, and the turns on the column are very close. The small interridge space allows better adhesion of the screw to a hard metal surface. Screws are usually made charcoal black or oxidized.

The price will be slightly higher than that of a screw for fastening a wooden material. The diameter of the rod can be from 3.5 to 5 mm. The longer the barrel, the correspondingly thicker the product. To understand the dimensions of self-tapping screws for metal, you can study the following table.

All data in the table are indicative. Some manufacturers do not pay attention to GOST and independently designate the parameters of their products. That is why when buying you need to focus on specific tasks. To connect parts that are made of thin tin, it is not necessary to purchase a drill to make some kind of hole. If the workpiece thickness much more, then first you need to drill a hole in the diameter of which the screw will fit.

The press washer screw is made of galvanized steel and is used to fasten metal that has a thickness of about 0.9 mm or less. There are also white wood screws. It's the same fastener, which has a wide functionality. The washer, which is located on top of the hardware, will provide good pressure on several elements. Both short and long screws are available for sale.

Screws consisting of a lower drill, an upper washer and a barrel must be used to fasten metal, which has a thickness of 2 mm, the necessary hole is made with a drill before fastening. It is very convenient to use such self-tapping screws. You can save a lot of time and do it quality connection.

This information will allow you not to confuse the self-tapping screw for metal with fellow woodworkers, which will be discussed in detail below.

Self-tapping screws for wood

All screws that are intended for fastening wood are made with a rare thread pitch. The distance between the ribs will be much greater than with metal screws. This is because the tree is much more dense material than iron.

Self-tapping screws are available in different colors.

They can be:

gold;
galvanized;
black.

The color will make a difference for the specifications. Yellow and galvanized screws are coated with a special compound that protects them from rust. Black wood screws rust much faster. The color also provides an opportunity to choose a screw for some design solution. For example, to nail furniture hinges from yellow wood, it is better to choose a self-tapping screw of the same shade.

When you go to the store to buy, pay special attention to the length. It must be commensurate with the density of the connection. For example, if you need to fasten two wooden parts that are 50 mm wide, then you need to choose a self-tapping screw with a length of 75 mm.

Hardware is manufactured with various diameters. If you purchased screws with a diameter of 3.5 to 4.2, then you do not need to use a drill to pre-drill the surface. And other screws will turn on in a completely different way.

Wood is not metal, where the screw hole is pre-made a little wider than the diameter of the self-tapping screw. Working with wood will change completely in the right direction. Thus, if you bought a screw with a diameter of 4.5 mm, then the hole must be drilled with a diameter of 3.5 mm, and not as is the case with metal. If the self-tapping screw has a diameter of 5 mm, then the hole is made 4 mm. Only in this case, when attaching a tree, it is possible to avoid various troubles cracks, for example.

If the above proportions are violated, then insufficient adhesion density can be created, and this will ensure the fragility of the entire assembled structure. As a result, everything that was collected, after a short period of time, will be greatly loosened and simply fall apart. And then you have to start all over again. Learning from your own mistakes is useful, but this can be easily avoided if you first master the theoretical knowledge base.

Thread Differences

The thread of the screw is very important, since it is it that determines the scope of the self-tapping screws. There are several varieties.

A large thread that has a wide pitch. Such a tool can be used to connect elements that are made of wood, MDF, MDF or drywall sheets. Cost - from 62 rubles per pack. Some stores sell one at a time, but usually they produce different packs with a certain weight (1 kg, for example).
Fine thread with a low pitch. It is used to connect parts that are made of hardwood. The cost is approximately 140 rubles per pack.
A two-start thread, which is an alternation of low and high turns. Used to connect materials that have different densities, for example, drywall. The cost is 100 rubles per package.

Classification according to other components

There are some more nuances that you need to pay attention to:

Manufacturing material. Screws can be stainless steel, carbon steel or brass.
External coating. There are oxidized and phosphated, black and quickly rusting, as well as galvanized or completely uncoated.
The end of the trunk, which can be sharp and drilled.
Self-tapping weight. A table or diagram can help with this question, but weight is of little importance when choosing wood screws. Dimensions, tables exist, but few people pay attention to this parameter at all.

And there is also a very large number of different types and types of heads that are installed on self-tapping screws.

Types of heads

Secret, which is used so that there are no various protrusions at the attachment point. This self-tapping screw has a round head and has the shape of a funnel, which is completely recessed into the material.
Hemispherical. Acquired in order to fasten sheet materials. They have a wide contact area and a reduced column length.
Secret reduced. Provides a smooth transition from head to post. It takes a lot of effort to install.
Spherical, which has a large press washer. It has a very large bearing surface with a small head height. Usually used to connect soft and sheet materials.
Hexagonal is designed to work with a conventional screwdriver. This is the most common type of self-tapping screw, which can be easily screwed in without electrical equipment.
Hidden under a hex key. It is best to use if you need to mask the attachment points very well.

When working with screws, not only screwdrivers are often used, but also power tools such as drills and a screwdriver, and such tools should be handled very carefully.

Never work without safety goggles. The hardware may break and fly off into an unprotected area. If this happens, you should immediately seek help from a doctor.
Fasten your sleeves when working with power tools, as the fabric can be drawn into the device.
Remove children from the work area. All hardware is very sharp, and these small objects can attract a child. As a result, he will injure himself or swallow them.
When working with a screwdriver, always select the correct nozzle. If this is not done, then the head of the hardware will deteriorate, and all notches for engagement will simply be erased. In this case, the screw will have to be thrown out, but at first it will be complicated by the fact that it will be difficult to get it from the attached surface. And also apply sufficient force when twisting, because if you lightly press on the screwdriver, then the same incident described above will occur.
Pay special attention to marking work. No one will be pleased if the inaccuracy of the markup becomes noticeable only after the main part of the work done.

Fulfill all of the above rules and advice, and then the repair or any kind of construction event will take place without complications.

If you carefully study all the above characteristics, then you can easily find exactly the version of the self-tapping screw that is suitable for a particular situation. With the help of self-tapping screws, you can provide a very good fastening, but if it is used only for a specific purpose.

As already found out above, a metal screw can be very easily distinguished from a wood screw. The wood screw has a much larger pitch than for metal. This is due to the fact that the density of the tree is less, it is softer, and the structure of the fibers is porous. Screws for wood products are usually made with sharp and narrow tips, and therefore the holes that are made with them have smooth walls. And it is also worth noting that hardware for wood has a much lower price than those elements that are made for fastening metal products.

Thanks to information about wood screws, sizes, a table with thread pitch, you can fully consider yourself prepared for a purchase. the right tools for successful construction.

The main types of screws were presented. On the Internet, they are called more vulgarly, and therefore you can find the names "grouse", "seed" and the like. In the store, it's best to use the official "names" to avoid confusion.