Pre-drilling for a self-tapping screw. Safety precautions

Mounting conditions and pre-hole diameters for BEST-tapping screws

When we drive a self-tapping screw or a self-tapping screw into wood without pre-drilling, we have to constantly face the limit of the wood’s strength under the tip and thread runs and the increasing frictional force created by the wood pressing against the screw or screw shaft. Frictional forces increase due to the increased contact surface of the self-tapping screw or screw on the wood. As a result, no normal electric screwdriver has enough power to tighten the screw or self-drilling screw to the required depth when the rods are large enough or when screwing into harder types of wood or to a greater depth. And the electric screwdriver will only chirp loudly, hinting that the strength limit has been exceeded, and this is correct, because the screwdriver manufacturers do not like to repair free products, spoiled because of the stubbornness of the user.

There are general rules for using self-tapping screws on all materials.

  • First the marking of the points of installation of fasteners is performed.
  • If necessary, in hard material, the installation site is marked with a thin drill bit or simply by hitting the self-tapping screw with the point of the hammer.

For your reference! Usually, before screwing a self-tapping screw into wood, this operation is not required. the metal is easy to enter into soft materials and without pre-drilling.

  • Until the thread of the self-tapping screw starts to cut grooves and it takes a stable position, screwing is carried out at minimum speed.
  • Increase speed and pressure.
  • When approaching the flat to the surface of the material, the speed is reduced again and dokruchivayut metiz carefully, so as not to overtighten and not to break it.

However, not all people use an electric screwdriver, which has adjustable power, why buy extra power tool when there is a drill and an attachment for an electric screwdriver for screws. The drill, unlike screwdrivers, has no power regulation, and therefore when screwing self-tapping screws or screws of large diameter or depth, there are 4 possible scenarios:

  • You will break the threads on the head of the screw or screw, a very high probability, especially when tightening at high rpm.
  • You will ruin your electric screwdriver bit very quickly. But if you use a Chinese screwdriver, it can also happen with relatively low torque on the nozzle.
  • You break a screw that can not withstand the torque. not often, but it happens. The fact that the screws, unlike screws, are hardened and therefore more fragile than screws.
  • You will burn the drill when you tighten a lot of self-tapping screws at low speeds.

I do not think that at least one of these options will appeal to you, so it is better to spend extra time on drilling holes than to spend this time to repair the drill, buying new nozzles, unscrewing a broken screw.

Advantages and disadvantages of wood screws

Classic self-drilling screw is a rod with a head, which has a certain distance of the thread. As we will see next, the thread pitch of a self-tapping screw is its most important characteristic

There are varieties of self-tapping screws that are used in working with materials of different densities, both 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 screwdriver with a simple Phillips screwdriver.
  • Versatility. No need to use any additional components (washers, spacers).
  • High speed of execution of works.

The only drawback is considered to be some brittleness of screws (tin steel becomes brittle over time). The fastener, especially the phosphated one, can burst with even a small amount of force. And it can not be seen from the outside. Unlike self-tapping screws, nails do not have such a hidden defect.

However, not all people use an electric screwdriver that has adjustable power, why buy an extra power tool when there is a drill and an attachment for an electric screwdriver for screws. The drill, unlike screwdrivers, does not have power regulation, and therefore when you screw in screws or screws of large diameter or depth, there are 4 possible ways of course:

  • you break the threads in the head of the screw or self-drilling screw. a very high probability, especially when tightening at high RPM.
  • You will very quickly damage the nozzle on an electric screwdriver. But if the screwdriver bit is made in China, it can also occur at relatively low loads.
  • You break a screw that can not withstand the torque. not often, but it happens. The fact that self-tapping screws, unlike screws, are pre-tempered and are therefore more brittle than screws.
  • You will burn the drill when you drive a large number of self-tapping screws at low speeds.

I do not think that at least one of these options will appeal to you, so it is better to spend extra time on drilling holes than to spend this time repairing the drill, buying new attachments, unscrewing a broken screw.

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Types and classification of self-tapping screws

The key difference between self-tapping screws for wood. a wide thread pitch. It is this feature that distinguishes these fasteners from those designed for metal structures.

This feature significantly reduces the friction force, which allows you to screw in screws without much effort with a simple screwdriver. There are many classifications of self-tapping wood screws, depending on the features of the fastened surface, their shape and type of thread. Let’s look at each of them in turn.

Interesting fact! There are extremely small hardware. They received an interesting name. “sunflower seeds”, because their appearance resembles the shape of a sunflower seed. In some variants they are also called “bedbugs” due to the relatively large relative to the length of the stem cap.

Due to the fact that not everyone knows about the different types, and therefore, and the purpose of “consumables”, there are a lot of problems: the screws break, the process of work is complicated and delayed.

Depending on the nature of the treatment of the outer surface

No matter what size metiz, short or long, it is necessarily covered with a special surface that protects the metal from oxidation and further strengthens it.

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Black (oxidized) wood screws

Sometimes they are called self-tapping screws GD. drywall-wood. Due to the countersunk head, they are used for interior finishing work. After screwing in, such fasteners are practically invisible and lend themselves well to puttying and leveling work.

Such screws have a countersunk head, which allows you to “sink” metiz for a couple of millimeters

Design features of self-tapping screws GD:

  • Sharp tip. This feature saves time during installation work.
  • Rare thread pitch. Mostly used on hard rock, which allows screwing in the self-tapping screw easily and without effort.
  • countersunk flat.
  • Hardened metal.

There are two subspecies of black self-tapping screws:

  • Phosphated. It is a special coating that gives a black matte color. These are the most brittle self-tapping screws and are used for simple, low-pressure jobs. Their resistance to corrosion is low, so they should be used in places with low humidity.
  • Oxidized. These self-tapping screws are further treated with magnetic oxide, more wear-resistant. They do not look matt, but glossy.

Important! There is a variety of self-tapping screws GM. plasterboard-metal, they have, on the contrary, a frequent pitch, which makes the wood surface more loose and sloppy. Under the influence of loads, a shelf with such an improperly selected screw can break off.

And the thread can be applied to the entire length or cover the product partially. There are certain parameters: screws up to 55 mm long are full screw thread, from 65 to 75. in this case the thread length is 50 mm, and if the screw is over 90 mm, this figure reaches 60 mm.

Black self-tapping screws are most often used in combination with dowels. Among the disadvantages of masters 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. a rather high cost and softness of the metal, due to which they can bend during careless work with a screwdriver.

Universal self-tapping screw, galvanized

Galvanized fasteners are most often found in furniture structures. They have a silver hue and are also not hardened. But they are practically invisible in any structures.

Depending on the shape

Fasteners of this type differ not only in the composition of the coating and the width of the screw “step”, but also in the shape of the cap and its design. Depending on the nature of the work are divided into several types of its performance.

Self-tapping wood screws with a press washer

Press washer provides precise and strong fastening of thin sheets, for example, wooden or plastic panels, most often such screws have a slot for a Phillips screwdriver. Most often, self-tapping screws with a wood washer has a sharp tip and does not require additional drilling. The length of such screws varies from 13 to 76 mm, and their nominal diameter is 4.2 mm.

Self-tapping wood screws with hexagonal head

In appearance, these screws resemble an ordinary hexagon screw. This screw is sometimes called a “wood screw.

These self-tapping screws have a thickened core, for which it is obligatory to drill a hole

pre-drilling, self-tapping, screw, safety

They are used wherever sufficient force is needed, for example, to assemble and fix the rafters.

Furniture self-tapping screws. screws

Confirmat. a type of self-tapping screw that is familiar to anyone who has ever assembled furniture from the IKEA supermarket. Such hardware has flat head and concave hole for special Allen key.

Confirmat is a sufficiently strong fastener that can be screwed in without special power tools

Depending on the type of thread

Depending on the type of thread such self-tapping screws come in several variations:

  • Fully threaded. The easiest type of fastener. In this case, the thread is located along the entire length of the screw. This type of fastener creates the maximum possible and strongest possible bond with the wooden structure. Allows for high longitudinal loads. These self-tapping screws can easily be screwed into the wood at different angles.
  • Self-tapping screws with ribs. There is a cutter in the head of the screw, in the process of screwing it increases the diameter of the hole and allows you to effortlessly sink it into the wood. Self-tapping screws are sometimes equipped with a middle drill.
  • Self-adjusting screws. They are used for installing doorways, frames and window constructions. They feature countersunk heads with special notches and a sharp tip. Self-tapping screws of this type allow the adjustment of structures.
  • Insulating self-tapping screws. Such screws allow you to fix the batten on the rafters, beams, screw the grid to the rail. Most often there are two types of heads: semicircular with a press washer or cylindrical.
  • Self-tapping screw. Used for installation of wooden battens. At the end of the screw there is usually a drill bit, which allows you not to drill a hole in advance.
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The main types of threads of self-tapping screws

Depending on what materials are to be connected, choose a self-tapping screw with one or another type of thread. The following quantitative characteristics, which are traditional for threads, are taken into account:

But in addition to them has a significant impact on the self-tapping properties of the product has an angle at the apex of the thread profile α. The smaller the specified angle, the easier to screw the product, easier to form a thread in the hole, higher self-tapping properties.

Traditional screws, produced by the domestic industry (GOST 1144.80, GOST 1145-80), have this angle equal to 60º, as in the metric thread.

Modern self-tapping screws are made with an angle α=45º and less. These sharp threads are particularly effective when screwing into relatively soft materials such as wood, chipboard, plastic, etc.п

Self-tapping screws intended to be driven into metal (DIN 7976, 7981 7983) are made at large angles (generally 60º) to increase thread strength at the base of the profile. In addition, the cutting edge of the product is subjected to a special hardening heat treatment to ensure a hardness of 450HV. Metal self-tapping screws are highly standardized products and their threads are made in accordance with ISO 1478, EN 2478, DIN 7970. Their thread diameter is preceded by the letters ST (SCREW THREADS) in the drawing and design documents.

The table shows the main dimensions for the sharp end (type C) and the blunt end (type F).

To reduce the time of screwing into wood, as well as to prevent cracking of wood, special notches on the thread are used, which create additional cutting edges, and the wavy cutting edge of the thread itself.

Metal self-tapping screw with a washer and drill: types and sizes

Small dimensions. A big screwdriver, though light, can cause a lot of problems when working with it in difficult conditions.

A good screwdriver should have several speeds, two at least.

Here, perhaps, are all the main characteristics of the ideal screwdriver for installation of corrugated board.

For example, I use a screwdriver like the one in the picture. It is lightweight and fits well in your hand, has two batteries, as well as two speeds.

Naturally such a screwdriver will cost a lot, but if you are a professional installer, you should think about such a useful accessory.

If the frequency of use of a screwdriver is extremely small, and the amount of work is minimal, then you can do with cheaper options.

But anyway we do not recommend you to buy a frankly bad screwdriver, because as the popular wisdom says. “a miser pays twice”.

Key opening of door locks of any security service Locks Center: http://topzamkov.ru/center-zamkov.html

Profiled sheeting C20 and Moscow region

Using self-tapping screws for concrete without drilling, safety precautions at work

Concrete and brick surfaces surround a person in almost every apartment or house, but to fix a screw in them is not so easy. Sometimes you need to hang a picture or a mirror, and sometimes it happens that the whole cabinet. For such work will need special self-tapping screws in concrete, because there are also screws for wood and metal.

Types of self-tapping screws for concrete

In turn, self-tapping screws on concrete are divided into several types. Some of them have a galvanized surface, so they can be used both inside and outside the room. They look silver, so they can hardly be confused with other types. If the work is planned indoors without an excess of moisture, you can buy yellow and black self-tapping screws. Also screws differ in the size of the pitch of the thread, and the shape of the head.

What are roofing self-tapping screws??

Roof screw is a screw of complex design. It is equipped with a hexagon socket for a wrench, and a tip in the form of a drill. It also includes a metal washer with an attached elastic gasket.

All metal parts are corrosion-resistant coated or made of stainless steel.

Technical characteristics of roofing screws

  • the shape of the head. round with a screwdriver slot, hexagonal, with the head digging into the surface
  • Size. from 16 to 150 mm in length, 4.8, 5.5, 6.3 mm in diameter
  • Purpose. fixing roofing materials to the crate or the installation of crates to the rafters / other
  • material used. carbon steel, stainless steel
  • material used for fastening. wood or metal.

Purpose of fasteners

Self-tapping screw serves to firmly fasten the elements between the structures:

  • The tip in the form of a drill helps without the help of pre-drilling and unnecessary damage to the details to penetrate the base material;
  • A solid thread provides a durable and secure grip;
  • Large-diameter washer ensures a good grip with the fastened material and reduces the load on it in the place of attachment;
  • Elastic gasket, tightly clamped between the washer and the roof, provides a waterproof fastener;
  • Screw head gives the connection aesthetic appearance and provides the builder easy to install it.

Variety of roofing screws

There are two basic types of roofing screws. on metal and wood, very different tip, diameter, type of thread. For fixing roof elements that are not in direct contact with water, you can use self-tapping screws with a washer.

When installing the rafters or other elements with a large distance between the installed surface and the wooden substrate can be used with screws with incomplete thread. When buying among the technically identical self-tapping screws you can choose galvanized or painted in the desired color.

How to choose a quality fastener

Choosing the fastener, you must first calculate its number and type for each type of work. For the rafters most often use nails or galvanized self-tapping screws, for the crate. self-tapping screws with press washers, and special roofing.

After determining the necessary characteristics of self-tapping screws. size, coloring, diameter, type of base, it remains to check the quality of the potential purchase:

  • On the head of the screw manufacturer puts stamped brand, if not, be wary of a cheap knock-off of low-quality steel;
  • the box must indicate the thickness of galvanizing, the permissible value. more than 12 microns. Complete absence of the box with the specified characteristics. a clear indication of poor quality;
  • The gasket must be firmly attached to the washer, be at least 2 mm thick, and can withstand without peeling test compression of the washer with pliers;
  • If the self-tapping screw is painted, the paint coating on the washer should not crack when it is bent with pliers;
  • among other equals, justifies itself buying a brand European products, with a manufacturer’s warranty on the highest quality of steel used and tested for resistance to temperature fluctuations and prolonged exposure to alternating loads.
pre-drilling, self-tapping, screw, safety

Whether you need to drill a hole for a self-drilling screw in wood?

If the metal to be drilled or fastened screw in the metal is less than 0.5 millimeters thick. then there is no problem, it does not even need to pre-drill. But if the thickness of the metal is greater, such as 0.8 millimeters or 1 millimeter, you must first drill a hole for the installation of the screw.

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Drill diameter must exactly match the diameter of the dowel, if the structure is attached to a brick. solid or concrete wall. If you attach to loose wall, the diameter of the drill should be 1-2 mm less than the diameter of the dowel. It is important that the depth of drilling should always be 5 mm more than the length of the dowel.

Self-tapping roofing screws enlarged drill 12,5mm (PT5)

Self-tapping roof screws enlarged drill 12.5 mm (PT5) Purpose: The main purpose of the screw. installation of metal shingles and corrugated board to the roof structures, the thickness of which exceeds 6 mm.

Special design features. Screw head is made in the form of a hexagon, the steel washer has a diameter of 16 mm, a rubber seal ensures reliable waterproofing fasteners. The tip of the screw is made of a 12,5mm long drill bit.

Fixing material. The product is made of galvanized steel. The rubber seal is made of EDPM rubber.

Mounting. For installation it is recommended to use an electric drill with a special attachment. Pre-scrape and nail the mounting location. The recommended minimum thickness of steel structures to be fastened 1.5 mm. The recommended maximum thickness of the mounted structures, in which the drilling is carried out. 12mm.

Name of goods pieces in package
Self-tapping roofing screw (cu.drill (coarse.fascia.), 5,519 5 000
Self-tapping roofing screw, uv.drill (croup.facet.), 5,525 4 300
Self-tapping roofing screw, g.drill (coarse.fascia.), 5,532 3 600
Self-tapping roofing screw, uv.drill (coarse.fascia.), 5,538 3 100
Self-tapping roofing screw, g.drill (coarse.fascia.), 5,551 2 000
Self-tapping roofing screw, uv.drill (coarse.facet.), 5,564 1 500
Self-tapping roofing screw, g.drill (coarse.facet.), 5,576 1 200
Self-tapping roofing screw, ov.core drill (coarse.facet.), 6,3 19 3 500
Self-tapping roofing screw, g.drill (coarse.facet.), 6,3 25 3 000
Self-tapping roofing screw, ov.drill (coarse.fascia.), 6,3 32 2 500
Self-tapping roofing screw, g.drill (coarse.facet.), 6,3 38 2 000
Self-tapping roofing screw, gv.drill (coarse.prepackaged.), 6,3 50 1 500
Self-tapping roofing screw, g.drill (coarse.facet.), 6,3 64 1 200
Self-tapping roofing screw, uv.drill (coarse.bass.), 6,3 76 1 000
Self-drilling roof, Priv.drill bit (coarse.fascia.), 6,3102 800
Self-tapping roofing screw, g.drill (coarse.facet.), 6,3127 600
Self-tapping roofing screw, g.bit (coarse ).facet.), 6,3152 500
Self-tapping roofing screw, g.screwdriver (small.facet.), 5,519 250
Self-tapping roofing screw, g.drill bit (small.fascia.), 5,525 250
Self-tapping roofing screw, g.drill (small.fascia.), 5,532 200
Self-tapping roofing screw, g.drill (small.fascia.), 5,538 150
Self-tapping roofing screw, g.drill bit (small.fascia.), 5,551 100
Self-tapping roofing screw, screwdriver, self-tapping screw, roofing screw, screwdriver (small ) 6,3 32.drill (small ) 6,3 50.facet.), 5,564 100
Self-tapping roofing screw, grip, screws, screws, screws, screws, screws, screws, screws, screws.drill.phase.), 5,576 50
Self-tapping screw for roofing, Ú.drill (small.fas.), 6,3 19 250
Self-tapping roofing screw, uv.drill bit (small.fas.), 6,3 25 200
Self-tapping roofing screw, g.drill bit (small.facet.), 6,3 32 150
Self-tapping roofing screw, g.drill (small.fascia.), 6,3 38 150
Self-tapping roofing screw, uv.drill bit (small.fascia.), 6,3 50 100
Self-tapping roofing screw, uv.drill bit (mag.facet.), 6,3 64 50
Self-drilling roofing screw, Uv.drill (small.facet.), 6,3 76 50
Roofing self-tapping screw, gv.drill (small.facet.), 6,3102 50
Self-tapping roofing screw, g.drill bit (small.facet.), 6,3127 50
Self-tapping roofing screw, borer, 6.3 19. drill bit (small.facet.), 6,3152 50
Name Nominal screw diameter, mm Screw length, mm thread pitch, mm Head Weight (1000 pcs.), kg
Self-tapping roofing screw, angled. drill, 5.519 5,5 19 1,81 SK 8
Self-drilling roofing screw, lug. drill, 5.525 5,5 25 1,81 SK 8
Self-tapping roofing screw, lug. drill bit, 5.532 5,5 32 1,81 SK 8
Self-tapping roofing screw, 8,538 g. drill, 5,538 5,5 38 1,81 SK 8
Self-tapping roofing screw, angled. drill, 5,551 5,5 51 1,81 SK 8
Self-tapping roofing screw, mit. drill, 5,564 5,5 64 1,81 SK 8
Self-tapping roofing screw, angled. drill, 5.576 5,5 76 1,81 SK 8
Self-tapping roofing screw, angled. bit, 6,3 19 6,3 19 1,81 8,820 6,3 19
Self-tapping roof screw, angled. drill, 6,3 25 6,3 25 1,81 SK 10
Self-tapping roofing screw, uvel. drill, 6,3 32 6,3 32 1,81 SK 10 9,15
Self-tapping roofing screw, lug. drill, 6,3 38 6,3 38 1,81 SK 10
Self-drilling roofing screw, lug. drill, 6,3 50 6,3 50 1,81 SK 10 12,93
Self-tapping roofing screw, lug. bit, 6,3 64 6,3 64 1,81 SK 10
Self-tapping screw for roofing, lengthening. drill, 6,3 76 6,3 76 1,81 SK 10
Self-tapping roofing screw, lenght. drill, 6,3102 6,3 102 1,81 SK 10 21,38
Self-tapping roofing screw, lug. drill, 6,3127 6,3 127 1,81 SK 10 25,33
Self-tapping roofing screw, lag. drill, 6,3152 6,3 152 1,81 SK 10

For see our price list. You can buy metric fasteners wholesale, with delivery across Russia. Also recall that all fasteners can be ordered and in stainless steel

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