Self-tapping screws for wood: a table with dimensions, features of choice and nuances of use
The market for fasteners for fixing various structural elements made of various materials is quite extensive. These are screws and anchors, bolts and studs, as well as brackets and other fasteners. When installing products and structures from lumber, self-tapping screws for wood are often used. Dimensions, table and price of these products, features of use on different materials - these issues will be discussed in this publication homemaster.techinfolux.com/en/.
Self-tapping screws for wood differ in size and materials used in the manufacture
The content of the article
- 1 Advantages and disadvantages
- 2 Types of wood screws
- 3 Documents regulating the production of wood screws
- 4 How and with what screws are fixed
- 5 How to choose - editorial recommendations homemaster.techinfolux.com/en/
- 6 What is the difference between self-tapping screws for wood and metal
- 7 How much are wood screws - price overview for 1 kg
- 8 Video: overview of wood screws
Advantages and disadvantages
Self-tapping screws for wood are the type of fasteners that almost every user is familiar with, regardless of place and region of residence, type of activity and place of work. This is due to ease of use, variety of sizes and low cost. In addition, the advantages of using self-tapping screws for wood include such indicators as:
- the reliability of fixation "in the body" of the wooden structure is ensured by the presence of a thread, by means of which the self-tapping screw is screwed in without breaking the wood fibers, as is the case when using nails;
- versatility - the ability to use for fastening various wooden structures and products from panel materials made from woodworking waste in various industries and construction;
- a variety of design features, such as the shape of the thread and grooves on the head, as well as the presence of a cutter on the tip of a self-tapping screw (on some brands), allows you to use, using various types of tools, on different types of materials without damaging the integrity of their structure;
- the presence of slots under the head allows you to "drown" the self-tapping screw in a wooden structure without performing additional operations (countersinking) and damaging the latter.
Types of threads for self-tapping screws for various purposes and their areas of application
The disadvantages of wood screws are:
- the possibility of using only for the installation of structures with a low mass, which is due to the strength of the metal from which they are made;
- models equipped with a press washer, as well as universal use, may damage the material to be fixed when tightened;
- when installing structures of sufficient thickness, as well as when using special types of self-tapping screws (furniture production - confirmations), it is necessary to pre-drill holes, which increases the complexity of the work performed.
Self-tapping screws - confirmations used in furniture production and for joining structures made of board materials (chipboard, MDF, etc.)
Types of wood screws
The industry produces various types of fasteners designed for different types of materials, while self-tapping screws for wood, in addition, are classified according to such indicators as the nature of the outer surface treatment and shape, by the type of thread and geometric dimensions.
By the nature of the outer surface treatment
The raw materials used in the manufacture of self-tapping screws of this type are carbon and stainless steel, as well as brass. To impart strength and durability to the final product during the production process, the surface of the self-tapping screw is treated with special chemical compounds during operations such as:
- phosphating - processing with phosphates, as a result, the surface of the self-tapping screw becomes black;
- oxidation - processing with magnetic oxide, the result is a black product with a slight sheen.
Note! Phosphated and oxidized self-tapping screws are black, which makes it possible to determine their type quite simply, purely visually.
Oxidized wood screws
In addition to black products, manufacturers produce brands of self-tapping screws with an additional anti-corrosion coating:
- galvanized - obtained by applying a layer of zinc, which, depending on its chemical composition, can be silver or yellow;
- yellow passaged - these products, in addition to galvanizing, are treated with chromic acid, resulting in a yellow product.
Galvanized wood screws
By form
This type of fasteners is produced by manufacturers for various purposes of use, which leads to differences expressed in the form of a self-tapping screw, namely:
- With a press washer. The press washer is a self-tapping head of this type. Its main purpose is to tightly press sheet materials without penetrating the assembled products. As a rule, structures of this type are made of carbon steel with subsequent galvanizing of the surface.
Self-tapping screw with press washer
- With a hex head. This design of fasteners has another name - "wood grouse" and is intended for the assembly of large and heavy structures. To tighten products of this type, wrenches and other locksmith tools are used that correspond to the dimensions of the hex head.This type of self-tapping screws can be used for fastening wooden structures to concrete and brick foundations, as well as for installing various technological and household equipment on wooden surfaces.
Hex Head Fasteners
Important! When using fasteners with a hex head, to facilitate their screwing in, it is necessary to pre-drill in the place of installation of the self-tapping screw with a drill of a smaller diameter than its diameter.
- For roofing works. This type of self-tapping screws can be equipped with a drill end or without it, which simplifies installation work on the roof, as well as a hex head and a double washer made of metal and rubber. The washer serves to prevent moisture from entering under the roofing and provides elasticity of the connection, which is necessary for the long-term operation of the roof.
Roofing screws are available in different colors and lengths
- Confirmates. This type of self-tapping screws is used in the manufacture of furniture and is distinguished by the presence of a blunt end in its design. For screwing in fasteners of this type, hexagons are used that correspond to the size of the recess made in the head of the self-tapping screw.
By thread type
The type of thread is one of the main differences between different types of self-tapping screws. There are three types of threads in total:
- wide step;
- small step;
- two-start thread.
Self-tapping screws with different thread pitches are used on various types of materials, depending on their structure and density. For example, products with a wide pitch are used when installing soft materials (spruce, pine, drywall, etc.), and with small ones when using dense materials. products made of birch, plastic and metal.
Self-tapping screw with double thread
Dimensions of wood screws
The assortment of self-tapping screws by geometric dimensions is very extensive, which is expressed in different diameters and lengths, depending on the shape of the product and the thread that determine their purpose.
Note! The diameter of a self-tapping screw is determined by its circumference, taking into account the thread protrusions.
The diameter can be 1.6 mm - for black and galvanized grades with a wide thread pitch, up to 12 mm - for confirmations and wood grouses. The length of a self-tapping screw equipped with a countersunk head is determined by its full length, and for products with a convex head, by the length of its rod. The length and technical characteristics of black wood screws with a wide pitch are shown in the following figure.
Correspondence table of technical characteristics of products and their geometric dimensions
Documents regulating the production of wood screws
At present GOST 1145-80 (ST SEV 2327-80) “Countersunk head screws. Design and dimensions (with amendments N 1, 2) ". This document defines the geometric dimensions and shape of the head, the mass of products and their quality characteristics, as well as the characteristics of the slot (number, radius, depth). In addition, GOST regulates the labeling of self-tapping screws, which greatly simplifies the selection of the desired fastener from the catalog for specific use cases.
How and with what screws are fixed
To drill self-tapping screws, a hand-held locksmith tool (wrenches, heads, hexagons, screwdrivers) and an electric hand tool (screwdriver, electric drill) equipped with a set of special bits and accessories are used.When performing work, the marking of the installation locations of the fasteners is initially performed, after which, using a sharp object (awl, drill, etc.), a depression is made in the wooden surface, into which a self-tapping screw should be placed. When using confirmations and wood grouses, as already written above, it is necessary to drill a hole with a drill with a diameter smaller than the used fastening element.
Correct and incorrect fixing depth of countersunk self-tapping screws
After that, the self-tapping screw should be drilled into the marked place or prepared hole using the selected hand or electric tool.
Important! When performing pre-drilling at the end of this operation, it is necessary to reduce the rotation speed of the tool so as not to damage the material to be fixed and not to rip off the screw head.
How to choose - editorial recommendations homemaster.techinfolux.com/en/
Due to the fact that the range of fasteners is quite extensive, sometimes it is not easy to choose the right product the first time. In this case, you should contact the professionals who can tell you what to look for when choosing, so as not to be mistaken.
Installation of a self-tapping screw using a screwdriver
Our editorial staff formulated their recommendations as follows, namely:
- The geometrical dimensions of the fasteners must correspond to the dimensions of the products to be mounted and their mass.
- For use in a humid and other aggressive environment, self-tapping screws with a protective layer should be used, and its presence can be determined by the color of the product.
- The thread pitch must correspond to the strength of the material to be mounted, which should be taken into account before choosing fasteners.
- The notch on the head of the self-tapping screw is also a selection condition, because the convenience of installation work and the type of tool used depend on its type.
- The quality of self-tapping screws is guaranteed by their manufacturer, so it is better to choose a product made by a well-known company that has proven itself only from the good side.
Installation of a self-tapping screw using a screwdriver
What is the difference between self-tapping screws for wood and metal
The main difference between self-tapping screws for wood and analogs intended for metal is the thread pitch, which is due to the density of these materials. Another difference between self-tapping screws for metal is the presence of a self-tapping head that allows you to mount metal without pre-drilling it.
External differences between wood and metal screws
How much are wood screws - price overview for 1 kg
Fasteners are sold both in stores within walking distance, and in retail chains of building materials and metal products, as well as in organizations specializing in similar products. If in small stores self-tapping screws are sold by the piece and by weight, then in specialized organizations they are sold only by weight. The following table shows the average cost of various types of self-tapping screws, as of the beginning of the third quarter of 2018, when sold through retail chains.
| Product type | Average cost (as of July 2018) for 1 piece, rubles | Average cost (as of July 2018) per 1 kg, rubles |
|---|---|---|
| Black phosphated | 0,28-3,76 | 180 |
| Black oxidized | 0,55-3,62 | 195 |
| Galvanized | 0,15-4,63 | 200 |
| Yellow passable | 0,18-5,58 | 210 |
| With press washer | 5-340 | - |
| "Capercaillie" | 0,96-46,44 | 500 |
| Roofing | 0,6-5,75 | 220 |
| Confirmates | 1,5-15 | 150 |
In hardware and fastener stores, you can always find self-tapping screws of the required standard size and in accordance with the intended use
Video: overview of wood screws
In order to imagine what wood screws are and what are their differences, the following video will tell.
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