The name “self-tapping screw” has long been heard and most people know very well in general terms what this fastener roughly represents.
Builders actively use the same screws for metal when carrying out repairs, in construction work and in everyday life for connection various elements. In stores they are sold by weight or in small batches, but large items are also purchased individually.
Features of product selection
There is a huge selection in construction stores and bases. self-tapping screw elements- this is the official name of fasteners in catalogs - according to shape, material used, dimensions, purpose and other functions. Naturally, a number of questions arise on this topic, since an inexperienced beginner may get confused in such a variety, and specialists do not always understand the differences and use one type of fastener for all types of work. To clarify, this important topic should be analyzed in more detail.
Self-tapping screws for metal
When buying self-tapping screws, every informed buyer focuses on very specific problems that these accessories should solve. Initially, a logical correlation is observed: for metal a self-tapping screw for metals should be used, for roofing - a roofing screw, and for wood, accordingly, for wood. Parts used for metal work are presented in two varieties: with a pointed end and a drill end.
With pointed end
The appearance of pointed self-tapping screws used for metal work is very reminiscent of traditional screws from the times of the USSR. They are made of good quality metal and have dense threaded threads, the interridge interval is small. This is done deliberately to improve the connection between the screw and the solid material.
More often there is a spread of screw diameters on metal in the range of 3-5 mm, and its value increases as the length of the product increases.
Manufacturers produce such elements with the following parameters:
- length 10-50 mm with thread pitch 5 mm;
- 60−100 mm in increments of 10 millimeters;
- 11−120 mm with 15 mm thread, quite rare;
- 125−220 mm, cutting 20 mm.
However, the above data is approximate, since there are many manufacturers of this fastener, and the supplier himself regulates the dimensions of the products.
To fix 2 mm metal there is no need to create preliminary holes, sharp end the screw will pierce them itself. But with a greater thickness of the elements being connected, it is necessary to drill a passage with a diameter slightly smaller than that of a self-tapping screw for a tighter fit. This method will allow for reliable adhesion to the part.
Self-tapping screws for metal are made from durum varieties first-class steel. They are supplied for sale with a galvanized or oxidized protective coating.
The color of commercially available pointed self-tapping screws for metal is mainly black, metallic or gold.
By the type of product you can find out what parts it is intended for connecting:
With drill end
Such screws have certain differences. Characteristic features such screws from the previous type are:
Self-tapping screws with a drill for metal No pre-drilling required. The tip pierces the material, making a passage for itself and immediately twisting into the base being fastened. The specially shaped cap ensures a tight connection. If the fit is not accurate, it is not recommended to unscrew the product and reuse it, since the tip will already be blunt.
Wood fasteners
Possess distinctive feature- have a rare thread pitch. It is clear that wood is soft and pliable, not too dense material for construction, which is why the coils are mainly distributed along the core.
The dimensions of the diametrical section of fasteners for wood do not differ from those for metal, and their length varies widely from 11 to 200 mm inclusive.
The smallest representatives of this category of self-tapping screws are called “seeds” in everyday slang, since their shape resembles sunflower seeds,
You can usually screw in wood fasteners without pre-drilling a hole. However, it is advisable to screw a large self-tapping screw with a length of 150 mm and a diameter of 4 mm into a pre-drilled channel so as not to cause cracking of the materials being fastened.
Furniture screws
From the name it is clear that furniture screws are intended for assembling furniture elements. Their length is traditionally 50 mm. It is necessary to screw the confirmations into the prepared channel, that is, a pre-drilled hole, since the end part of the self-tapping screw is blunt.
The head of the fixing screw for assembling furniture has a slot niche for an internal hexagon key. The diameter of the confirmat is the same along the entire length, but has a smooth thickening in front of the cap so as not to tear off the element under significant loads.
Modern furniture is made mainly from MDF, chipboard and other glued materials, and furniture screws are designed for assembling parts that are not solid in composition. The confirmat has high thread ridges and a fairly flat head, which in total gives good fastening reliability and allows you to recess the head and cover it with a plug to match the base material.
Parts with press washer
This option has already been discussed in the information on self-tapping screws for metal with a drill end, however, this type should be separated into a separate subgroup due to important feature- the presence of an increased contact area of the cap. The press washer tightly holds pressed wooden slats or metal sheets with a thickness of up to 10 mm.
They do not have a characteristic color; usually there are shiny versions of a silver tone.
Hex head element
In appearance, this type of self-tapping screw resembles an ordinary bolt. But still it is different a number of signs:
- rare screw thread;
- slightly pointed end.
The main use is for fixing massive elements of large objects. The “hex self-tapping screw” is usually screwed into wood, but when using a dowel it is also suitable for concrete. Dowels for hex head screws should be selected according to the diameter and be two sizes larger than the self-tapping screw.
Any work with such fasteners is carried out with 10, 13 and 17 mm wrenches.
Roofing fasteners
The hex head, depending on the size of the screw, comes in only two options - 10 and 8 mm. Roofing screws have the following features:
The rubber washer-lining performs a dual role:
- a good insulating gasket that prevents moisture from flowing under the cap into the hole for fastening the roof;
- elastic shock-absorbing joint seal.
Self-tapping screws for roofing are made in any color form for existing RAL palettes roofing materials.
Anti-vandal types
Such screws may be similar in appearance to other options, but upon closer inspection the difference is obvious.
It consists of special types grooves on the caps, these can be multifaceted, star-shaped or paired notches. They cannot be unscrewed with a regular tool, which explains the name of the fastener.
This article describes the most common types of self-tapping screws found in work. There are many types, including those with a narrow focus, so it is advisable to try to select exactly those fasteners that are intended for connecting specific materials. You should not save and use available fasteners, since poor connection of surfaces is possible, which will lead to a violation of the strength of the connection.
This is only half the battle. To complete the fastening task, you need to screw more screws, directly into the drilled hole or into the dowels.
A self-tapping screw is a type of fastener that is a rod with a sharp thread and a head designed to transmit torque when screwing while simultaneously cutting threads in the elements being connected.
The range of self-tapping screws for wall mounting on sale tends to be infinite. The task of selecting hardware (from the phrase “metal products”) for fastening to the wall seems insoluble. But if you put everything into detail, it becomes clear what kind of 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 types protective coatings. Oxidized, black - for fastening in rooms with normal humidity. Galvanized silver - for indoor and outdoor use. Galvanized, yellow – for indoor and outdoor use. Have a golden color decorative look. Look good on door locks and gold-plated hinges.
Types and types of self-tapping screws
Depending on the type of thread, there are self-tapping screws: with a universal thread, with a rare thread pitch, and with a frequent one. 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 to which the sheets are screwed is located, and screw the self-tapping screw through the drywall into the profile. If the screw does not have a drill at the end, then it is first necessary to drill a hole in the metal with a diameter equal to the internal diameter of the screw thread.
For fastening sheets roofing iron, there are special galvanized self-tapping screws in two sizes: 4.8×16 and 4.8×19 with a hex head. A type of self-tapping screws with a rare thread pitch are designed specifically for screwing into soft materials, such as plastic, plaster, asbestos, wooden board and the like. Universal – designed for screwing into any materials. Of course, it is better to use specially designed ones, but any will hold securely.
| List of popular types of screws, their purpose and sizes | ||||
|---|---|---|---|---|
| Appearance of the self-tapping screw | Self-tapping thread pitch | Scope of application of self-tapping screws | Self-tapping screw diameter, mm | Range of screw lengths, mm |
 |
Average | Universal 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 approach |
Self-tapping screws for fastening to metal sheets thickness up to 0.9 mm without dowel, pre-drilling of the hole is necessary. self-tapping screws come with a drill at the tip, but are more expensive |
||
 |
Rare | Self-tapping screws for fastening to soft materials without dowel – soft wood, 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 hammering 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 modern furniture made of wood, chipboard, plywood, etc. Requires pre-drilling of a hole with a diameter of 4.5 or 7 mm respectively | 5,0; 7,5 | 40; 50; 60; 70 |
 |
Variable with notch | Self-tapping screws for fastening to concrete or brick walls without dowels (dowels), screwed into a hole, 15 mm deep than the length of the screw to be screwed, 6 mm in diameter | 7,5 | 70; 90; 110: 130; 150; 180; 200 |
A separate line worth noting is the self-tapping screw - a confirmat, specially created for the manufacture of furniture from wood and chipboard. The confirmat type self-tapping screw, with a clean surface and a large area of the lateral surface of the thread, allows you to obtain a high-strength and precise connection of elements. The most popular confirmat size is 7×50. Before screwing the confirmat, a hole with a diameter of 4.5 or 7 mm is required, respectively. The confirmation head is made for a hex key.
To hide the head of a tightened self-tapping screw, Confirmat produces decorative plastic buttons - plugs of any color. The plug with its protrusion is tightly inserted into the hexagonal hole of the confirmator head and disguises it to match the color of the furniture.
It should also be noted that there are 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 with a hammer drill is not allowed. To make it easier to screw, a little bit of any machine oil should be injected into the hole before screwing. Used for permanent fastening. I don’t use them because they are difficult to tighten and even more difficult to unscrew.
There are also self-tapping screws that have a herringbone thread profile. They are driven 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 for stretch ceiling or when installing frames plastic windows. Their advantage is the speed of installation.
Types and types of heads for self-tapping screws
The head is the extended part of the self-tapping screw, designed to hold fixed objects and ensure the transmission of torque from the tool to the self-tapping 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 being fastened without a protrusion |
 |
Hemispherical | Holds the object firmly thanks to the fairly wide pressing area of the head |
 |
Hemispherical with press washer | With an increased area of the bearing surface of the head and a reduced 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 element being fixed; during installation it allows applying significantly more force than with a standard countersunk head |
 |
Hemispherical with large press washer | With very big bearing surface and reduced head height, this type of head is designed for securing soft sheet materials |
 |
Hexagon | The oldest head shape allows you to easily tighten self-tapping screws with great force using a power tool with a special hexagonal socket |
 |
Funnel-shaped countersunk with a thickening along the shaft, 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).
Selecting a self-tapping screw depending on the load
Self-tapping screws have a large margin of shear and bending strength. The main thing is to securely fasten it to the wall. How more porous structure wall material, the thicker and longer the dowel should be so that there is a large engagement area, and accordingly the standard size of the self-tapping screw. If in doubt about the choice, it is better to choose a larger 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 product being fastened | Standard size of the self-tapping screw depending on the wall material, excluding the thickness of the product being fixed | |||||
|---|---|---|---|---|---|---|
| Regular 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 | 4x40 | 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
An anchor is a type of finished fastener for securing heavy products by wedging into the wall. Anchor translated from German language means anchor. Practically, 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 screws 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 only possible when fastening in very hard materials, dense brick, concrete and stone. In everyday life, such cases may arise when attaching a heavy chandelier to concrete ceiling or during installation suspended ceiling large area. The use of an anchor is justified, for example, for fastening sports equipment in an apartment - rings, wall bars. Children's swings 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. Indispensable if you need to fasten two parts at once, for example a corner or a sheet to concrete wall. This type of anchor is convenient for securely mounting a heavy TV on the wall |
 |
The drive-in anchor is designed for fastening heavy objects on walls and ceilings made of concrete, non-hollow brick, and stone. | |
 |
Allows you to attach any product to the stud of an anchor fixed in the wall with an additional nut | |
 |
For hanging stationary products that need to be hung and removed periodically. For example, a chandelier or stretchers between two walls. | |
 |
Used for the same cases as the anchor hook, but eliminates accidental slipping of the fixed product | |
 |
For fastening hollow structures to 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 alternative way there is no 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.
(by the way, if you have ever looked for special fasteners for these purposes, there are none). A self-tapping screw is a reliable, but at the same time simple and affordable tool. In today's HouseChief review we will talk about how to choose the right screws for wood, and tables with sizes and prices will help you navigate their variety and choose correct option for a specific type of work.
Read in the article
Advantages and disadvantages of wood screws
Self-tapping screws appeared in Russia back in the sixties of the 20th century; the classic bolt was taken as the basis. However, if you look closely, its thread covers the entire surface of the rod, while the self-tapping screw does not. And the material used for the improved fasteners is more durable.
There are types of self-tapping screws that are used when working with materials of different densities, such as metal, plastic, and wood. Sometimes these fasteners are also called “hardware,” short for “metal product.”
"If we talk about the advantages of such fasteners, they are obvious:
- High strength and rigidity of the connection.
- Reusable.
- Adjustment of the required screw-in depth.
- You can do without electricity, because you can screw in a self-tapping screw with a simple Phillips screwdriver.
- Versatility. There is no need to use additional elements (washers, gaskets).
- High speed of work completion.
The only drawback is considered to be some fragility of the screws (hardened steel becomes brittle over time). The fastener, especially with a phosphated coating, can burst under even slight force. And this cannot be seen from the outside. Unlike self-tapping screws, nails do not have such a hidden defect.
Types and classification of self-tapping screws
The key difference between wood screws is the wide thread pitch. It is this feature that distinguishes these fasteners from those intended for metal structures.
This feature significantly reduces the friction force, which allows screws to be screwed in without special effort using a simple screwdriver. There are many classifications of wood screws, depending on the characteristics of the surface being fixed, their shape and type of thread. Let's consider each of them in turn.
Interesting fact! There are extremely small hardware. They received an interesting name - “seeds”, since their appearance resembles the shape of sunflower seeds. In some variants they are also called “bugs” due to the cap being relatively large in relation to the length of the stem.
Due to the fact that not everyone knows about different types, and, consequently, the purpose of the “consumables”, a lot of problems arise: the screws break, the work process is complicated and delayed.
Depending on the nature of the outer surface treatment
It doesn’t matter what size the hardware is, short or long, it is necessarily covered with a special surface that protects the metal from oxidation and further strengthens it.
Black (oxidized) wood screws
Sometimes they are called GD self-tapping screws - plasterboard-wood. Thanks to the hidden cap, they are used for internal ones. After screwing in, such fasteners are practically invisible and lend themselves well.
black self-tapping screws for wood
Design features of self-tapping screws:
- Sharp tip. This feature allows you to save time during installation work.
- Rare thread pitch. They are most often used on soft rocks, which allows screws to be screwed in easily and effortlessly.
- Hidden hat.
- Hardened metal.
There are two subtypes of black self-tapping screws:
- Phosphated. This is a special coating that gives it a matte black color. These are the most brittle self-tapping screws; they are used for simple types of work with a low degree of pressure. They have low corrosion resistance, so should be used in areas with low humidity.
- Oxidized. These self-tapping screws are subject to additional treatment with magnetic oxide, making them more wear-resistant. They look not matte, but glossy.
Important! There is a type of GM screws - plasterboard-metal; on the contrary, they have a frequent pitch, which makes the wood surface more loose and sloppy. Under the influence of loads, a shelf with such an incorrectly selected screw may break.
Moreover, the thread can be applied along the entire length or cover the product partially. There are certain parameters: self-tapping screws up to 55 mm long come with a full screw thread, from 65 to 75 - in this case the thread length is 50 mm, and if the self-tapping screw is more than 90 mm, this figure reaches 60 mm.
Comment
Ask a question“The softer the type of wood, the more sparingly we use the self-tapping screw. Then the surface will not “bump”, and for high-quality fastening of parts, just a screwdriver will be enough.
"Most often, black self-tapping screws are used in conjunction with dowels. Among the disadvantages, experts call their low resistance to moisture.
Yellow-passivated and galvanized wood screws
This type of hardware is resistant to corrosion. They are most often used as decorative fasteners. Among the disadvantages are the rather high cost and softness of the metal, due to which they can bend during careless work.
Galvanized fasteners can most often be found in furniture structures. They have a silver tint and are also not hardened. But they are practically invisible in any design.
galvanized wood screws
Depending on the shape
Fasteners of this type differ not only in the composition of the coating and the width of the screw “pitch”, but also in the shape of the head and its design. Depending on the characteristics of the work, there are several types of its execution.
Wood screws with press washer
The press washer ensures precise and strong fastening of thin sheets, such as wood or plastic panels, most often such screws have a slot for a Phillips screwdriver. Most often, self-tapping screws with a press washer for wood have a sharp tip and do not require additional drilling. The length of screws of this type varies from 13 to 76 mm, and the nominal diameter is 4.2 mm.
Wood screws with press washer
Wood screws with hexagon head
By appearance These self-tapping screws resemble a regular hexagon screw. This self-tapping screw is sometimes called a "grouse".
They are used where sufficient force is required, for example, for assembling and fastening rafters.
Wood screws with hexagon head
Furniture self-tapping screws
Confirmat is a type of self-tapping screw that is familiar to anyone who has ever assembled furniture from an IKEA supermarket. This hardware has a flat head and a concave hole for a special hex key.
Furniture self-tapping screws
Depending on thread type
Depending on the type of thread, such self-tapping screws come in several variations:
- Full thread. The simplest type of fastener. The thread in this case is located along the entire length of the screw. This type of fastener creates the maximum possible and strong adhesion to wooden structure. Allows you to withstand large longitudinal loads. Such screws can easily be screwed into wood at different angles.
- Self-tapping screws with ribs. There is a cutter in the head of the screw; during the screwing process, it increases the diameter of the hole and allows you to effortlessly sink it into the wood. Sometimes self-tapping screws are equipped with a middle cutter.
- Adjustment screws. They are used for installation doorways, frames and window designs. They are distinguished by countersunk heads with special notches and a sharp tip. Self-tapping screws of this type allow for adjustment of structures.
- Insulation screws. Such screws allow you to fasten the sheathing to rafters, beams, and screw the mesh to the batten. Most often they have two types of heads: semicircular with a press washer or cylindrical.
- Self-tapping flugel. Used for installation of wooden sheathing. There is usually a drill at the end of the screw, which eliminates the need to drill a hole in advance.
Dimensions of wood screws - table
Wood screws are available in various types and sizes, here are the main ones:
| Nominal diameter, mm | Length, mm | Outer thread diameter, mm | Internal thread diameter, mm | Cap width, mm |
| 2,5 | 12-25 | 2,25-2,55 | 1,1-1,5 | 5,1 |
| 3 | 12-45 | 2,75-3,05 | 1,5-1,8 | 6 |
| 3,5 | 12-50 | 3,2-3,55 | 1,75-2,15 | 7 |
| 4 | 16-70 | 3,7-4,05 | 2-2,5 | 8 |
| 4,5 | 25-80 | 4,2-4,55 | 2,22-2,7 | 8,8 |
| 5 | 30-120 | 4,7-5,05 | 2,52-3 | 9,7 |
| 6 | 40-240 | 5,7-6,05 | 3,22-4,05 | 11,6 |
State standards for wood screws
According to GOST parameters, wood screws received a certain marking - they correspond unified standard number 1145. This GOST was adopted back in the 80s of the last century. It hasn't changed since then.
The standards clearly standardize the fastener manufacturing process down to the size of its head and the applied coating. Thus, you can know exactly which screw is needed for certain purposes and buy it anywhere in our country.
How and what to fix self-tapping screws with
Among the variations of tools with which self-tapping screws work well, the first place, naturally, is occupied.
Comment
Team leader of the repair and construction company "Dom Premium"
Ask a question"When working with hard rocks wood may benefit from pre-drilling. In this case, select a drill diameter that exactly matches the size of the screw. For fiberboard - a millimeter less, for soft wood and chipboard - 3 millimeters less.
"Many types of screws can be screwed in using a regular Phillips screwdriver. In this case, it is better not to make unnecessary efforts, but to screw in evenly and carefully. Remember, oxidized screws are very fragile.
Safety precautions when working with the tool
Let's consider a short set of rules for working with the tool:
| Illustration | Description of action |
 | When working with a screwdriver, you should never put your hand under the tool. Even if you think you're in control, leaning slightly can cause the tool to slip and cause injury. |
 | Never try to drill a self-tapping screw into a knot. Such areas are often the densest. In addition, the mounting location cannot be called durable. It is better to choose a place a little to the left or a little to the right. |
 | Always keep the tool firmly in line with the screw you are turning, whether you are working at an angle or not. In relation to each other they must create a single line. |
First of all, choose a self-tapping screw based on the density of the surface being fastened or drilled.
Consider the width of the surface and the size, as well as the expected load. When attaching drywall, follow the required step - the screws should be fastened no further than 7 cm from each other. It is better to choose self-tapping screws with anti-corrosion treatment. If necessary, do not be lazy and pre-drill.
All photos are clickable, for a detailed view, click on the photo.
Self-tapping screws are a simply necessary thing in construction; you can’t do without them if you decide to hang a shelf, cabinet, picture, assemble furniture, or build a house. There are quite a lot of types of self-tapping screws, as well as building materials for which they are intended. Let's look at the most common ones. To tighten, you will need screwdrivers or.
Wood screws.
Their main distinctive feature is a rare thread pitch. The distance between the threads is noticeably greater than, for example, with metal screws. This is due to the fact that wood itself is less dense and hard than iron. Can be black, white, golden colors, depending on the color of the material you are working with. The most commonly used color is black. If you need to screw, for example, furniture hinge yellow, of course it’s better to take a self-tapping screw to match.
Length of screws. From the shortest 11mm seeds, the so-called seeds, they got their name because of their small size, approximately the size of a sunflower seed, up to the longest 200mm.
You need to select a self-tapping screw so that the connection of the parts is tight. For example, if you are fastening two 50mm bars, take a self-tapping screw with a length of at least 75mm, or 90mm is possible.
Diameter of screws. Black self-tapping screws (the most commonly used) have a diameter of 3.5mm, 4.2mm, which allows you to tighten them without pre-drilling.
Yellow ones have a diameter of 2.5 - 6 mm.
Holes for screws will be required if the screw diameter is 4.5 mm or higher. If the block or workpiece is thin, you can drill a hole for 4mm hardware.
For 4.5mm, a hole of 3mm-3.5mm will be required, depending on the density of the wood.
A 5mm self-tapping screw requires a 3.5mm-4mm hole.
For 6mm - 4.5mm, then the wooden blank will not crack. Use regular drill for metal, since there are no drills for wood with a pitch of 0.5 mm.
You should also not drill a hole that is too large, otherwise the adhesion density will be low.
For black ones, you will need a screwdriver with a PH connector No. 2, or the same bit. For yellow ones
bit PZ No. 1, No. 2 or No. 3, depending on the diameter of the screw.
Self-tapping screws for metal.
As a rule, they have a frequent pitch, the distance between the threads is very small, unlike wood screws. Frequent steps are required for dense materials to ensure reliable adhesion.
Black screws for metal have a diameter of 3.5 mm. If you are screwing thin sheet metal, you don’t need to pre-drill it. If the thickness of the workpiece is 2mm or more, you need to make a hole of approximately 2.8-3mm.
They have a PH connector No. 2.
Self-tapping screws with press washer, galvanized, sharp(PH connector No. 2).
Allows you to fasten sheet metal up to 0.9 mm without drilling a hole. Also suitable for fastening wood.
The large cap allows you to press the material being fixed more tightly and serves as a washer. They have a diameter of 4.2 mm, length from the shortest to 13 mm, to the longest to 64 mm.
These can be used to fasten metal up to 2mm, without drilling a hole. There is a drill at the end; it seems to drill a hole for itself and screw it in.
For these you will need PH bit No. 2.
Designed for fastening roofing materials, as the name implies. Diameter 4.8mm and 6.3mm. Length from 19mm to 100mm. They come in different colors, depending on the color of the material, blue, brown, simply galvanized.
For these, you will need a bit with an 8mm internal hexagon if the diameter of the screw is 4.8mm, and 10mm if the diameter of the hardware is 6.3mm.
Has a rubber gasket to prevent the roof from leaking.
Furniture self-tapping screw (confirmed).
Used when assembling furniture, length 50mm, requires pre-drilling. There is a special drill for it, with two diameters, since its thickness is the same size at first, and thickens towards the end.
You will need a 4mm hex key if you are turning it by hand, or a bit for a screwdriver - HEX 4.
Hex Head Screw(sometimes called wood grouse).
Hex Head Screw
This is perfect for heavy structures, where special strength is needed. Designed for wood, thickness 6mm-10mm. Be sure to drill a hole for it before screwing it in. For a 6mm screw – 4.5mm, for 8mm – 6mm, for 10mm – 7.5mm-8mm.
To tighten such screws you will need spanner, the head has a hexagonal shape with a diameter of 10mm, 13mm, 17mm, depending on the thickness of the screw.
If you use a self-tapping screw with a dowel, then select the dowel so that its diameter is approximately twice the diameter of the self-tapping screw. For example, if the self-tapping screw is 3.5 mm, then the dowel is 6. If it is 4 mm or 4.5, then the dowel is 8 mm.
Make a hole in the wall the size of the dowel diameter.
Self-tapping screws, or self-tapping screw elements (official name), are familiar to everyone who has encountered fastening work during repairs and construction. However, the choice of self-tapping screws in construction hypermarkets can be confusing. Let's take a closer look at this type of hardware.
Let's immediately determine how a self-tapping screw differs from a screw and a screw, because in the eyes of a layman these fasteners are very similar. However, a screw has a smooth part behind the head before the thread begins, while a self-tapping screw does not. A screw's triangular thread completely covers the cylindrical surface, whereas a self-tapping screw does not. In general, a self-tapping screw is called a type of screw, which is distinguished by a thinner shaft and an increased thread height.
We should immediately highlight two main types of self-tapping screws: for wood and for metal. This is precisely the condition put forward by home craftsmen who come to the market or building materials hypermarket to buy screws. As you can see in the photo, the problem is in the cutting itself on the rod; for metal, you need a noticeably smaller one.
If we are talking about fastening drywall, then you should use self-tapping screws with a two-start thread, which alternates high and low curls. This allows you to connect materials with different densities. However, many simply use metal screws when attaching drywall to a metal profile. Or wood screws if the drywall is attached to a wooden base.
Self-tapping screws are made from stainless or carbon steel, as well as brass. Made of brass, suitable for use in conditions wet areas, but they are more expensive - important!
Self-tapping screws are called that for a reason - they can cut threads even in concrete or metal, whether you use a screwdriver or an electric screwdriver. Metal surface The self-tapping screw is hardened, that is heat treatment, and the end of the rod is made in the form of a drill, so it is perfectly screwed into the structures being fastened. Moreover, the hole turns out to be of exactly the required diameter, for a self-tapping screw.
The question often arises why some types of self-tapping screws have yellow. It all depends on the type of corrosion protection used. If galvanic plating with yellow or white zinc is used, the self-tapping screw will receive the corresponding color. Yellow screws, being the most resistant, are more expensive! White ones belong to the middle price category, and black ones are the most affordable.
We wrote in detail about the choice of screwdrivers depending on the type of slot. So, self-tapping screws, which are sometimes called hardware (“metal products”, one of the factory varieties), can be with:
- Straight slot on the head.
- Cross-shaped.
- TORX.
- Hexagonal.
Most often we use Phillips screws.
Self-tapping screws, of course, vary significantly in size. You may need to attach something to a thin surface or provide a more secure attachment to two fairly thick surfaces. Standard sizes leave:
- Length from 1 to 5 centimeters with a thread pitch of 5 millimeters. These are the smallest screws. Sometimes they are called "seeds".
- Length from 6 to 10 centimeters with thread pitch up to 10 millimeters.
- The length of the rod is from 11 to 12 centimeters with a thread of 15 millimeters. We admit that this type of self-tapping screws is rare.
- The largest self-tapping screws can reach from 12.5 to 22 centimeters in length and have a thread of 20 millimeters.
The specified dimensions may vary depending on the manufacturer, please take this into account. The main thing is that the length of the fastening part passes through the entire sheet of sheathing and fixes it on the sheathing! The most popular are self-tapping screws with a length of 25 and 45 millimeters.
Note that there are universal self-tapping screws suitable for wood, metal, and drywall, but professionals still prefer to use specialized ones. In addition, special mention should be made of roofing screws, which have special caps with rubber or silicone inserts to protect the roof material. They can also differ in the type of surfaces being fastened.
There is also confirmation, self-tapping screws, which are used in the manufacture of furniture. They are also called a screw tie, Euroscrew or Euroscrew. The confirmat is distinguished by a blunt end, a countersunk head, and connects parts made of MDF, wood, plywood, and other wood materials.
Based on the type of heads, self-tapping screws are usually divided into countersunk, semi-countersunk, semicircular with a press washer, simply semicircular, with a truncated cone, cylindrical and hexagonal.
Choose and install correctly, because often the strength of the entire structure will depend on a small self-tapping screw!