Self-tapping screws for wood are ordinary fasteners for all occasions. Self-tapping screws and screws What are the yellow self-tapping screws
This is only half the battle. To complete the task of fastening, you need to wrap more screws, directly into the drilled hole or into the dowels.
A self-tapping screw is a type of fastener, which is a rod with a sharp thread and a head designed to transmit torque when screwing with simultaneous threading in the connected elements.
The range of self-tapping screws for wall mounting tends to infinity. The task of selecting hardware (from the phrase "metal products") for wall mounting 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 (the 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.
Carbon steel self-tapping screws are available with the following protective coatings. Oxidized, black - for mounting in rooms with normal humidity. Galvanized silver color - for indoor and outdoor use. Galvanized, yellow - for indoor and outdoor use. They have a golden decorative appearance. Looks good on gold-plated door locks and hinges.
Types and types of screws
By 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 intended for screwing into metal sheets. For example, if you need to hang a heavy painting on a drywall wall. Find with a powerful magnet the place where the profile is, to which the sheets are screwed, and screw the self-tapping screw through the drywall into the profile. If a self-tapping screw without a drill at the end, then a hole must first be drilled in the metal with a diameter equal to the inner diameter of the self-tapping thread.
For fastening sheets of roofing iron, there are special galvanized self-tapping screws of two standard sizes: 4.8 × 16 and 4.8 × 19 with a hex head. A type of self-tapping screw with a rare thread, designed specifically for screwing into soft materials, such as plastic, plaster, asbestos, wood planks and the like. Universal - designed for screwing into any materials. Of course, it is better to use specially designed ones, but they will reliably hold any.
| A list of popular types of screws, their purpose and sizes | ||||
|---|---|---|---|---|
| The appearance of the self-tapping screw | Self-tapping thread pitch | Scope of self-tapping screws | Self-tapping screw diameter, mm | A number of lengths of screws, mm |
 |
Middle | 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, thread in two entry |
Self-tapping screws for fastening to metal sheets up to 0.9 mm thick without dowels, preliminary drilling of the hole is required. self-tapping screws come with a drill on the tip, but they are more expensive |
||
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Rare | Self-tapping screws for attaching 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 |
 |
Middle, 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. Pre-drilled hole with a diameter of 4.5 or 7 mm respectively | 5,0; 7,5 | 40; 50; 60; 70 |
 |
Variable notched | Self-tapping screws for fastening to concrete or brick walls without a dowel (pins), screwed into a hole, 15 mm deep more than the screwed-in length of a self-tapping screw, 6 mm in diameter | 7,5 | 70; 90; 110: 130; 150; 180; 200 |
A separate line worth noting is the self-tapping screw - a confirmation specially created for the manufacture of furniture from wood and chipboard. Self-tapping screw of the confirmat type, with a clean surface and a large area of \u200b\u200bthe lateral surface of the thread, allows you to obtain a high-strength and accurate connection of elements. The most popular standard size of the confirmat is 7 × 50. Before screwing the confirmat, drilling a hole with a diameter of 4.5 or 7 mm, respectively, is required. The confirmation head is made for a hex key.
To hide the head of a twisted self-tapping screw, the confirmat produces decorative plastic buttons - plugs of any color. The plug is tightly inserted with a protrusion into the hexagonal hole of the confirmation head and masks it to match the color of the furniture.
It should be noted that self-tapping screws for concrete, which are screwed in without a dowel, directly into the drilled hole. When screwing into porous material and with cavities with a perforator, it is not allowed to drill holes. to make it easier to screw, a little of any machine oil should be injected into the hole before screwing. They are used for fastening "forever". I do not use them, as it is difficult to tighten, and unscrewing is even more difficult.
There are also self-tapping screws with a herringbone thread profile. They are hammered into the hole simultaneously with the dowel with a hammer and are also designed to be fastened "forever". Their use is justified, for example, when attaching a baguette for a stretch ceiling or when installing plastic window frames. Their advantage is quick installation.
Types and types of heads for self-tapping screws
The head is an extended part of the self-tapping screw, designed to hold the objects to be fixed and providing the transfer of torque from the tool to the self-tapping screw.
| Types of heads and their purpose | ||
|---|---|---|
| Appearance | Head type | Appointment |
 |
Secret | After installation, the head of the self-tapping screw is completely recessed in the material to be fixed without a protrusion |
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Hemispherical | Holds the object securely due to the wide enough pressing area of \u200b\u200bthe head |
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Hemispherical with press washer | With increased head bearing area and reduced head height for fixing sheet materials |
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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, allows you to apply significantly more force during installation than with a standard countersunk head |
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Hemispherical with large press washer | With a very large bearing surface and reduced head height, this type of head is designed for fixing soft sheet materials |
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Hexagonal | The oldest shape of the head, allows you to easily tighten self-tapping screws with great effort with a power tool with a special hexagonal nozzle |
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Funnel-shaped countersunk with a thickening along the rod, for a hexagon wrench 4 mm | 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 screws depending on the load
Self-tapping screws have a large margin of shear and bending strength. The main thing is to securely fix it in the wall. The more porous the structure of the wall material, the thicker and longer the dowel should be, so that there is a large engagement area, and, accordingly, the size of the screw. If in doubt about the choice, it is better to choose a larger size self-tapping screw for fastening.
| Table for choosing a standard size of a self-tapping screw, depending on the load on one self-tapping screw of a fixed product | Self-tapping screw size depending on the wall material without taking into account the thickness of the fixed product | |||||
|---|---|---|---|---|---|---|
| Ordinary brick | Concrete | Tile | Aerated concrete | Wood | 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 is a kind of finished fastener for fixing heavy products by wedging in the wall. Anchor in translation from German means anchor. In fact, 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, screwed into a conical nut. The conical nut, entering the tubular split base of the anchor, pushes it apart, creating a large friction moment with the wall material. The use of anchors is possible only when anchored in very hard materials, dense brick, concrete and stone. In everyday life, such a case can occur when attaching a heavy chandelier to a concrete ceiling or when installing a large suspended ceiling. The use of an anchor is justified, for example, for fastening sports equipment in an apartment - rings, wall bars. Children's swing on anchors will also hold securely.
| Types of anchors and their purpose | ||
|---|---|---|
| Appearance of anchors | Name of anchors | Appointment of anchors |
 |
Anchor bolt with nut | Simultaneously serves as an anchor and a bolt. 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 mounting a heavy TV on the wall. |
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The drop-in anchor is intended for fastening heavy objects on walls and ceilings made of concrete, not hollow brick, stone. | |
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Allows to anchor bolt fixed in the wall, fix any product with an additional nut | |
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For hanging stationary items that must be hung up and removed periodically. For example, a chandelier or streamers between two walls. | |
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It is used for the same cases as the anchor hook, but excludes accidental slipping of the fixed product | |
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For fastening to walls of hollow structures | |
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Universal for fixing wood and metal frames, wood 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 associated with the implementation of fastening equipment. The purpose of half of the screws is unclear, but asking the seller is somehow awkward ... 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.
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 looking into GOST 27017-86which gives the following definition of a screw:
A screw is a fastener in the form of a rod with an external special thread, a threaded tapered end and a head at the other end, forming a thread in the hole of the wood or plastic product to be connected.
As follows from a document dated 1986, the use of this type of fastener involved pre-drilling the hole and limited the material of the fastened elements to wood or plastic. For this type of screws, brass, mild 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.
The self-tapping screw is a new round in the evolution of fasteners. Formally, it corresponds to the definition from GOST, which we gave above, but has significant constructive differences (the shape of the slot, thread, thread and tip) and is made of high-quality steels with corrosion-resistant coatings.
As the name suggests, the self-tapping screw can self-thread and can be used without pre-drilling. 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 handy tables for each type.
Decryption example
Screw 1 - 4 × 25 GOST 1145-80
4mm diameter x 25mm long mild steel screw, not platedStandardized labeling looks like this, but in practice it 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 quantities: length and diameter.
Universal screws
They are usually made with incomplete threads. Used for wood, chipboard and other 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.
| 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 when installing in dowels. It can be galvanized (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 |
Wood screw with hex head
DIN 571 and GOST 11473-75... Designed for fixing lags, rails and other tasks in which enhanced fixation is required. As a rule, it is produced 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, but differ in materials of manufacture, angle of approach and angle of thread profile (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 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 serves as 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 press washer
They are found on sale both with 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")
Similarly to its predecessor, it can be either sharp or with a drill. There is no dimensional ruler for this self-tapping screw and it is found in a single dimensional version:
Sharp tip - 3.5 x 11
With a drill bit - 3.8 x 11
Self-tapping screws with a hex head
Designed for working with sheet metal without preliminary hole preparation. Provides 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 thick metal (5mm or more). Tip length - drill determines the swing. 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
They are made with a countersunk conical reduced head, a cross recess, a two-start thread of a variable profile and a sharp tip. The dimensions of fasteners for mounting on a wooden frame or 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 plates and sheets of chipboard, fiberboard, plywood
As a rule, these are galvanized screws (FLUGEL) with a size of 5.0 x 36
Met with countersunk conical head and countersink incisions for countersunk holes ( DIN 7504P) with dimensions:
Roofing screws
When installing the roof, it is advisable to use standard galvanized self-tapping screws. They do not corrode. A table with a 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
Confirmation or "euro-screw" is a separate category of fasteners. It is designed for assembling 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 a characteristic difference. A special hexagon is required for screwing in.
Concrete screws
Screwed into a pre-drilled hole. It is not recommended to use a puncher. Hence the complexity of the process. Before screwing in, you need to drop a drop of machine oil - this will slightly facilitate the procedure. A type of fastener that is called "forever". Withstand high loads (up to 100kgs). Available: 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 a dowel and sometimes come with it.
Adjustment screws
A characteristic feature is the second thread. The first thread (usually a shallow one) is necessary for fastening to the base, the second is for mounting the substructure.
Popular screws are screws ∅6 mm and lengths: 60, 70, 80, 90, 100, 110, 120, 130, 145 mm.
Scaffolding screws
Screws-nails
Suspension screws
They are very convenient in everyday life, for example, a children's swing has been hanging on such a fastener for several years in the corridor of a city apartment. Installation and removal time is literally 1 second! There is no single standard for the size of this element, and each production forms a size ruler at its own discretion.
Cheat sheet for home craftsman
The following tables will help you navigate the selection of the required fasteners.
We distinguish the product by the type of thread
Self-tapping screws differ in the frequency of turns. Small pitch allows fasteners to be applied to metal parts. Sparse thread screws are intended for materials with low density. This includes: asbestos, gypsum, plastic and more. By their appearance, self-tapping screws can be classified as follows:
|
Thread pitch |
Special purpose |
|
Universal screws. Designed for fastening objects made of any materials (they are the most common). |
|
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Frequent, |
Designed for attachment to metal profiles up to 0.9 mm thick without using dowels (preliminary hole preparation is required, |
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Self-tapping screws for attaching parts made of soft materials (wood, plaster of paris, asbestos, and so on) without the use of dowels. |
|
|
Average, s |
Self-tapping screws for screwing into reinforced concrete or brick building objects by driving into a dowel. |
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Asymmetrical |
Self-tapping screws for fastening elements of modern furniture made of wood, chipboard, plywood, etc. (requires preliminary drilling of a hole with a diameter of 4.5 or 7 mm, respectively). |
|
Interlaced with notches |
Self-tapping screws for attaching to reinforced concrete or brick parts of buildings without a dowel (pins), (screwed into a hole with a diameter of 6 mm and a depth of 15 mm exceeding the immersed part of the self-tapping screw). |
It's all in 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 fastened without a protrusion. |
|
Profile - hemisphere |
Holds the attachment firmly thanks to the increased area of \u200b\u200bthe pressure head. |
|
Profile - hemisphere with a small press washer |
It has a larger working surface area of \u200b\u200bthe cap and its lower height. Used when installing sheet materials. |
|
Small secret |
It has a small working area and a gentle transition from the cap to the threaded barrel. During installation, it is fixed both in a stationary object and in an attached part. Allows during the mounting process to apply significantly more force than in the case of a conventional countersunk head. |
|
Profile - hemisphere with a large press washer |
It has a larger working pressure area and a lower head height. Intended purpose - attaching low density sheet metal parts. |
|
Hexagonal |
The configuration of the head, allows you to tighten the screws with less effort, achieving a strong pressure of the fastened objects. |
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Funnel-like secret with a thickening on the body of the rod |
Allows to mask the connection. Allows you to close the hat with a decorative plastic cover. Screwed in with a specific wrench (4 mm). |
The fact that it took a lot of effort to screw in does not mean titanic torments that will have to go through if it becomes necessary to unscrew the screw. Therefore, every time the "eternal" method is advised, it is worth thinking about expediency. 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, it is necessary to give an objective assessment of the load to which the fastener will be subjected. If we are talking about a "carnation" for a picture on a wooden wall, it makes no sense to spend money on expensive screws.
The screw-in tool is used both manual and electric. A screwdriver is often enough. This method will not allow achieving high labor productivity when it comes to professional work and large amounts of fasteners. The familiar screwdriver is optimal for work.
Schlitz - smile :) Unbelievable, but true
The Japanese factory Komuro Seisakusho has released a batch of fasteners with a non-standard smiley slot. The author of a 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 question of the purpose and sizes of fasteners. We will be grateful for your 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 threads and splines.
Currently, a large number of fasteners are on sale - anchor, dowel, etc., however use of self-tapping screwsstill 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 way. This results in a reliable fastening.
Self-tapping screws - technical characteristics
Self-tapping screws are a fastening material consisting of a slotted head and a threaded rod, as well as a tip of a certain shape. They are produced using standard quality structural carbon steel, as well as from low-alloy steel of improved quality and using non-ferrous metal alloys (copper, brass, zinc and aluminum). In addition, some types of self-tapping screws are coated with anti-corrosion compounds, usually zinc. We will tell you about the difference between self-tapping screws below.
Types of self-tapping heads
High-quality self-tapping screws are distinguished by the types of heads:
Self-tapping screw with a hex head, made as a merged press washer, and with a type-setting. The hexagon is screwed in with an ordinary wrench;
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 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 are the slots for self-tapping screws
Slots for screws and screws are necessary to transfer torque from a screwdriver or screwdriver to the fastener itself. There are quite a few of them, and we will only mention the most common ones.
Straight slot... Previously, it was quite popular, but recently it has been almost completely squeezed out by a cruciform slot.
Cross recess... The product of the company "Phillips" came to the liking of the consumer, as it significantly facilitated the process of screwing in the self-tapping screw.
Pozidrive cross recess... Fasteners with such splines allow for more efficient transmission of force from the tool. This was made possible by the smaller apex angle and additional antennae. However, this requires more accurate centering in the slot of the screwdriver or bit, which slows down the work somewhat.
Torx sprocket... It holds the record 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.
Square slotsand splines with internal hexagon practically not used, except perhaps in the furniture industry.
Even less often, special splines are used, or, as they are called in another way - splines "with a secret".
The thread is also diverse, and which screws to use depends on the type of material being fastened:
Coarse thread... Self-tapping screws with a rare thread pitch allow you to fix soft materials - gypsum, asbestos, plastic and soft wood. 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 screws, suitable for almost all types of fastened materials. Diameters of medium 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 a dowel. Self-tapping diameters from 3 mm to 8 mm, length - from 12 mm to 200 mm;
Frequent thread in two steps... Self-tapping screws designed for fastening to metal sheets up to 0.9 mm thick have such a 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, the length is from 12 mm to 200 mm;
Asymmetric thread... This type of thread is intended for self-tapping screws used in furniture production, it is used to fasten furniture elements made of wood, plywood or chipboard. Pre-drilling required, self-tapping diameters - 5 mm and 7.5 mm, length - from 40 mm to 70 mm;
Variable serrated thread... The purpose of self-tapping screws with such a thread is to attach 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 fix or screw something yourself. It's no secret that this requires special accessories, and the choice of all kinds of nails, nuts, screws, screws and other fasteners in modern hardware stores is very impressive! You stand, look and just eyes run up. 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 kind of screws they are and what materials can be used for fastening.
1.What is a self-tapping screw?
Self-tapping screw- it 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
Self-tapping material
Self-tapping cover
- Phosphated (black) self-tapping screws are made of carbon steel with subsequent phosphate treatment. Used in rooms with high humidity.
- Oxidized (black color). These self-tapping screws are made of carbon steel with a protective oxide film applied. 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 yellowself-tapping screws differ from the previous ones only in color, they are used mainly for door hinges in a decorative gold color, since they are visually less noticeable against their background.
- Without cover.Used for interior work in normal humidity.
Self-tapping screw design
Head (1)
This is the upper part of the self-tapping screw, with the help of it torque is carried out. There are various forms:
Thread (2)
Tip (3)
Slot (4)
This is a recess of a special shape and the head end.
3. Purpose
- Universalthe self-tapping screw has a countersunk head with a Phillips recess and a sharp tip. Has a galvanized finish. It can be used both outdoors and indoors, suitable for finishing in damp rooms. It is used for fastening wood, plywood, chipboard, sheet metal (pre-drilled), and other materials. They have a length from 12 to 200 mm, a thread diameter from 3 to 6 mm.
- For wood. Wood screws are used to join plywood, wood, as well as their varieties. Fastening wooden products with self-tapping screws is much strongerthan fasteners made with nails, this is due to the presence of a thread. 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 screw is screwed in more smoothly, and the sharp tip sets the direction, using a nail, you can split a wooden surface, accidentally falling between the fibers. Self-tapping screws for wood come in different sizes, depending on the thickness of the elements to be connected, but they will all have distinctive features: a countersunk or semicircular head with a cross recess, 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 not lessthan on ¼ part thickness of wood, then your fastening will be reliable and will be able to withstand the load.
- For drywall. can be attached either to special metal profiles or to a wooden frame, depending on the material, there will be differences and self-tapping screws required 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 the installation time. For fastening to wood, choose a self-tapping screw with a rare thread pitch and a sharp end. Insert the sharp end into the drywall approximately 1 mm before screwing in. Whichever method of installation you choose, drywall screws will have common features: black color, which speaks about thanks to the oxide or phosphate coating, countersunk head, which should sink 1 mm into the sheet, cross recessso 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 acute or drill tip and head in the form press washers, which increases the contact area and provides a tighter pressing of the sheet elements to each other. Drilling advantages tip is that there is no need for pre-drilling, self-tapping screws are enough easy to screw in into a hard metal surface, excluding the formation of chips or scratches. Self-tapping screws with a drill bit 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 good bonding of materials of different density. They are used mainly for fastening wood to metal, up to 2 mm thick. They also have anti-corrosion properties and high strength values. To connect metal products, self-tapping screws with a drill tip and hex head or self-tapping screws with a truncated cone (" flea») And a drill bit. "Fleas" are used for metal thickness not exceeding 2 mm. Hexagonal self-tapping screws are very convenient to tighten with a key. To choose the right length self-tapping screw, you need to know the thickness of the part that you want to attach to the base and add to this thickness 10 mm... Since for the reliability and strength of the fastener, 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 with a pitch of 0.5 mm.
- For a window profile.There is no separate category of self-tapping screws for, as such, there is, but very often it is necessary to attach the same profile for the 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, scratches the plastic at the same time, or even scrolls after installation, therefore experienced installers advise using self-tapping screws with a drill at the end... They are not taken away when screwed in, the window frame does not deteriorate and they screw in much easier. The size of the screws is dictated 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, it is better to use small " flea»With a drill at the end and a head in the form of a press washer, if the handle - then with a hidden head with a Phillips recess. For reliable fastening, no more than 2-3 mm of thread entry into the window profile is sufficient.
- On concrete.In order to screw something to or, it must be borne in mind that during installation, the self-tapping screw will be subjected to very heavy loads. For concrete work, choose a self-tapping screw galvanized steel with a sharp end and cruciform or six-pointed slot... 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 you can do without preliminary drilling, with a solid base it is necessary to make a preliminary deep hole.
- For corrugated board.To fix and choose galvanized self-tapping screws, visually similar to screws. The head of such self-tapping screws has hex shape, covered with polymer 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 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, which is necessary for a certain type of work, it is necessary, also among the many options choose really quality, durable fasteners that will not fail at the most crucial moment. Just take a close look at the screw. It must comply with such simple criteria:
If you see that the screws you have selected 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 is a very large number of different modifications, some of which are intended exclusively for wooden structures, and the other helps to connect various metal units, furniture elements or glass products.
Possession of accurate information about what types of screws are, their sizes, as well as knowledge and understanding the differences materials for their manufacture will allow you to correctly fulfill the task set for yourself.
After all, no one wants to buy unnecessary thing, spoil the part, and then go and buy everything new. Of course, bad experiences are also very useful, but you can avoid them by studying the necessary materials before buying.
To clarify this issue, you need to study necessary information and instructions.
The basics
First, you should clearly find out for yourself that any screw element will be intended for a specific purpose and have its marking... Experts pay special attention to the fact that when working with metal, you need to use only a metal oxidized self-tapping screw, and with a roof - a roofing screw. Such distinctions are the basis for 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 self-tapping screws for wood, first you need to pay little attention to their brothers, which are intended for fastening metal. This is necessary so that a person who comes to a hardware store does not rush to buy first comer 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 what they look like. They are made of high-quality metal, and the turns on the column are very close. The small inter-ridge space allows for better adhesion of the screw to a hard metal surface. The screws are usually made coal black or oxidized.
The price will be slightly higher than that of a screw for fastening wood material. The rod diameter 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 only. 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 sheet metal, it is not necessary to purchase a drill to make a hole. If the thickness of the workpiece much more, you first need to drill a hole in the diameter of which the screw will fit.
The screw with a press washer is made of galvanized steel and is used to fasten metal that is approximately 0.9 mm thick or less. There are also white wood screws. It's the same fastening element, which has a wide functional purpose. The washer, which is located on top of the hardware, will ensure a good clamping of several elements. Both short and long self-tapping screws are available for sale.
The screws, consisting of the lower drill, the upper washer and the barrel, must be used to fasten the metal, which has a thickness of 2 mm, the required hole is made before fastening with the drill. It is very convenient to use such self-tapping screws. You can save a lot of time and perform quality connection.
This information will allow you not to confuse the metal screw with fellow wood, which will be described 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 that of metal screws. This is because the tree is much more dense materialthan iron.
Self-tapping screws in different colors are on sale.
They may be:
- gold;
- galvanized;
- black.
Color will play a role in performance. The 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 a design solution. For example, to nail furniture hinges yellow wood, it is better to choose a self-tapping screw of the same shade.
When going to the store to shop, pay special attention to the length. It must be measured with the density of the connection. For example, if you need to fasten two wooden parts that are 50 mm wide, then the self-tapping screw must be selected with a length of 75 mm.
The hardware is manufactured with different diameters. If you have 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 hole for the screw is pre-made slightly wider than the diameter of the screw. Working with wood will change quite 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 in the case of metal. If the screw has a diameter of 5 mm, then the hole is 4 mm. Only in this case, when fastening the tree, you can avoid various troubles in the form of cracks, for example.
If the above proportions are violated, then an insufficient adhesion density can be created, and this will ensure the fragility of the entire assembled structure. As a result, everything that has been collected, after a short period of time, will be strongly loosened and simply fall apart. And then you have to start all over again. Learning from your mistakes is useful, but you can easily avoid this if you first master the theoretical knowledge base.
Differences in thread
The screw thread is very important because it determines the scope of the self-tapping screw. There are several varieties.
- A coarse thread that has a wide pitch. Such a tool can be used to connect elements that are made of wood, fiberboard, chipboard, MDF or drywall. Cost - from 62 rubles per package. Some stores sell one piece at a time, but usually they produce different packs with a certain weight (1 kg, for example).
- Fine thread with low pitch. It is used to join parts that are made of hardwood. The cost is approximately 140 rubles per package.
- Double start thread, which is an alternation of low and high turns. They are used to join materials with different densities, for example, drywall. The cost is 100 rubles per package.
Classification by 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.
- Outer cover. There are oxidized and phosphated, black and quickly rusting, as well as galvanized or completely uncoated.
- The end of the barrel, which can be sharp and drilled.
- The weight of the screws. A table or diagram can help with this question, but weight is of little importance when choosing wood screws. Sizes, tables exist, but few people pay attention to this parameter at all.
And there are 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 in the material.
- Hemispherical. It is purchased to bond sheet materials. They have a wide contact area and a reduced post length.
- Concealed reduced. Provides a smooth transition from head to post. To make the installation, you need to apply great effort.
- Spherical, which has a large press washer. It has a very large bearing surface with a low head height. Usually used for joining soft and sheet materials.
- The hexagonal one is designed to work with a conventional screwdriver. This is the most common type of self-tapping screw that can be easily screwed in without electrical equipment.
- Countersunk with a hex key. It is best used 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 screwdrivers, and such tools should be handled with great care.
- In no case should you work without protective glasses. 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 may be pulled into the appliance.
- Move children out of the work area. All hardware is very sharp, and the child can be attracted by these small objects. As a result, he will injure himself or swallow them.
- Always use the correct bit when working with a screwdriver. 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 this is complicated by the fact that it will be difficult to get it out of the attached surface. And also apply sufficient force when tightening, because if you press lightly 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.
Do all the above rules and advice, and then the repair or any kind of construction activity will take place without complications.
If you carefully study all of the above characteristics, then you can easily find exactly that version of the self-tapping screw that is suitable for a specific 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 self-tapping screw for wood has a much larger pitch than for metal. This is due to the fact that the density of the wood is less, it is softer, and the structure of the fibers is porous. Wood screws are usually made with sharp and narrow tips, and therefore the holes that are made with them have smooth walls. 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 the information about self-tapping screws for wood, sizes, a table with a thread pitch, you can fully consider yourself prepared for purchase the right tools for a successful construction.
The main types of screws were presented. On the Internet, they are called more popularly, and therefore you can find the names "wood grouse", "seed" and the like. It is best to use official "names" in a store to avoid confusion.
