Self-tapping screw with press washer: characteristics and varieties

Description

Self-tapping screws with a press washer differ from their own kind in the shape of the head; as the name suggests, it is made in the form of a small washer, which, when screwed in, provides maximum clamping force, reliably securing sheet materials. That is, their main scope of application is the installation of profile sheets, plywood sheets, and so on; their design does not allow the head to penetrate deep into the material.

Although they are useful as wood screws, they are most often used to fasten metal sheet materials, for this reason they are made of durable steel grades.

Particularly expensive and high-quality ones are made of titanium; they are used where strength and reliability are especially important.

The white or yellow color, which makes it possible not to stand out against the background of the fixed sheets (even after painting), is provided by a layer of zinc, which reliably protects the fastening materials from corrosion and gives an attractive appearance. The threads on them are frequent, it provides reliable grip.

As a rule, such self-tapping screws are short, since the sizes of self-tapping screws with a press washer, which are in greatest demand, are 15-25 mm (length).

Varieties of self-tapping screws with a press washer.

There are two types of self-tapping screws with a press washer: a self-tapping screw with a sharp tip and a self-tapping screw with a drill-shaped tip. Each of these types has its own advantages and its own area of ​​application.

• Self-tapping screw with a press washer with a sharp tip.

In the production of such self-tapping screws, high-quality carbon steel is used, which has the highest strength. Anti-corrosion protection is provided by a thin layer of zinc applied to the surface of each product. The press washer of such a self-tapping screw is attached to the head with a cross-shaped notch from below by welding. The main advantages of these fasteners are their endurance and resistance to impacts of various types.

Most often, such self-tapping screws are used when it comes to joining wood materials and creating various wooden structures. The press washer perfectly presses the sheet material to the base, giving the entire connection strength and reliability. Purely visually, such self-tapping screws on the surface of wooden sheathing look very aesthetically pleasing, which is one of the reasons for their high popularity.

• Self-tapping screw with a drill-shaped tip.

For the manufacture of self-tapping screws of this type, higher quality steel is used, and the same zinc protective coating is applied to their surface. The hemispherical head of such fasteners is practically indistinguishable from the head of the first type of self-tapping screws. There is also a press washer on its back side, and a cross-shaped notch is applied to the upper part. The main difference is that the self-tapping screw rod is made in the form of a drill, capable of independently making holes in the surface of the material. Hence the differences in the scope of application - a self-tapping screw with a drill is used if the work is carried out with metal. The presence of a drill helps not only to achieve a very high-quality connection, but also to significantly speed up the work time. At the same time, to work with such a self-tapping screw, one screwdriver is enough - the drill on the tip of the self-tapping screw can independently cope with making holes in the metal without the help of a drill or screwdriver.

Types of self-tapping screws with a press washer

Products are divided into two main types, depending on their tip.

Self-tapping screws with a press washer and a sharp tip. They are practically no different from ordinary ones; their heads are rounded and adapted to work with a screwdriver or a bat. You can tighten it either manually or using a screwdriver. They are perfect for working with both metal sheets and wood, chipboard, etc.; in this case, additional drilling is not required.

If sheets thicker than 0.9 mm are used in installation work, drilling will be necessary, otherwise its tip will roll over and will not be able to pass through the material.

Self-tapping screws with press washer and drill.

Instead of a regular tip, a miniature drill is used here. Such products are made from durable types of steel, since drilling a hole requires that the material of the screw be denser than the material of the structural elements being fastened. They can be used to secure sheet materials whose thickness exceeds 2 mm.

The caps can have exactly the same appearance as sharp self-tapping screws, but they are subject to greater load, so the caps can be shaped like a hexagon, so they can be tightened with a wrench.

Self-tapping screws with a press washer may differ from each other both in the shape of the head and in the scope of application; let’s look at a few more varieties.

Roofing screws.

Self-tapping screws with drills and a pressure head are often used in roofing work, but in this case it is necessary that they be supplemented with rubber washers. One of the main tasks of the roof is to insulate the building from moisture, and fastening elements in this case can become a weak point. The rubber gasket, subjected to pressing pressure, fits tightly to the surface of the roofing material and provides complete waterproofing.

Particularly expensive varieties may have a polymer coating, which means that already at the production stage they are already painted in a certain color.

In terms of performance characteristics, they are not inferior to their analogues; modern polymers can form a thin and extremely durable film, which will perfectly protect the product from moisture and corrosion, make the fastening no less reliable than other types, and at the same time have an excellent appearance.

They are used to secure painted profiles; if the colors match, the fastening materials will practically not stand out against the background of the sheets.

Classification

Characteristics of self-tapping screws with a press washer:

• standard size (length, outer diameter of the head, thickness, thread pitch and other parameters of the self-tapping screw with a press washer);
• what alloy the fasteners are made of (steel, brass);
• sharp tip or drill.

Depending on the density of the materials to be fastened, choose self-tapping screws with a sharp tip or with a drill. Hardware with a sharp tip can be screwed in with a screwdriver or screwdriver without pre-drilling, if the density of the base allows it. Similar fasteners are used when working with wood, plywood, metal profiles and sheet metal. If the sheet metal thickness is more than 0.9 mm, you must first drill a hole for the self-tapping screw, otherwise the hardware will get stuck in the metal and will not pass through the material.

To fasten sheet steel with high strength values, self-tapping screws with a press washer and a drill at the end are used. Fasteners for metal must be denser than the material being joined, which is done when using hardware with a drill. For such fasteners, the head is often made in the shape of a hexagon. During the screwing process, more effort must be applied, and the strength of the cap must be ensured. For manual installation of self-tapping screws with a drill and press washer, use a wrench of the appropriate size.

Self-tapping screws are also classified into hardware for woodworking and metalworking. Wood screws have wider threads and a higher ridge. For wood species with high density, hardware with wavy or torn threads is used, which prevents the formation of cracks after the fasteners are screwed in. Metal hardware is distinguished by smaller and often threaded threads, which ensure ease of installation and strength of the connection.

Another type of fastener is a roofing screw with a press washer. It has a drill and a hexagonal pressing head. To ensure the tightness of the connection with the hardware, use a rubber sealing washer. Since moisture resistance is of paramount importance for the longevity of the roof, a rubber gasket is necessary when making fastening connections. Roofing screws are produced with a colored polymer coating, which is resistant to mechanical stress, changes in humidity and ensures a long service life of the roofing material. The design of the self-tapping screw with a drill allows you to install fasteners without pre-drilling.

Typical sizes of galvanized sharp

Among the regulatory legal acts in force in the Russian Federation, there are also standards that define standards for the production of fasteners.

Regulatory government intervention is necessary here, since self-tapping screws are widely used in construction work.

Really high-quality products are always marked with the markings provided for by the current GOST.

Galvanized sharp self-tapping screws are made of steel; after the first stage of production, the finished products are coated with a protective layer of zinc, which protects them from corrosion, significantly increasing their service life. According to the standard, the head is made in a round shape with a cross-shaped slot.

Products for woodworking are distinguished by carvings with a wide pitch, thanks to which they do not scroll or break off. There are also varieties for screwing into hard wood; in such products, the thread is made in a torn or wavy form, it allows you to break wood fibers, reduce the degree of delamination of the wood, reducing the likelihood of cracks.

Self-tapping screws with a pressing washer and a sharp tip are used for fastening hardboard, plywood, and other sheet materials to a wooden base. They can also be used to secure plastic cladding material; here, a pressing washer is necessary to protect against crushing.

Self-tapping screws with a pressing washer, dimensions for products with a sharp tip:

Typical sizes with drill

For their production, the most durable steel alloys with a high carbon content are used, this makes them as durable as possible, providing the ability to drill into the metal surface.

The tip is crowned with a drill, the head can be hemispherical or hexagonal in shape, the standards also provide for the presence of sealing rubber washers on the variety for roofing work.

The design feature makes it possible to carry out installation work without first making holes in the metal surface. Otherwise, they are no different from their counterpart with a sharp tip.

Self-tapping screws with a pressure washer, dimensions for products with a drill:

Types by tip type

Self-tapping screws for metal have two types of tips: a sharp tip with a thread and a tip with a drill. They are used for fastening sheets of different thicknesses.

Self-tapping screw with a sharp tip, dimensions and characteristics

Self-tapping screw for metal with a sharp tip

This type of hardware has a pointed tip with a knurled thread. Used for fastening metal up to 0.9 mm thick. Can be used to attach elements to metal or plastic. For fastening to wood, self-tapping screws with a sharp tip and a large thread pitch are used. The head can be equipped with a press washer (including a painted one) or without it.

If it is necessary to install metal with a thickness of more than 0.9 mm using these types of hardware, it is necessary to first drill a hole at the joint. It is recommended to use a drill 3.2-3.5 mm in diameter.

Table 1. Dimensions of roofing screws for metal with a sharp tip

Self-tapping screws with drill, dimensions and characteristics

Self-tapping screw for metal with a drill
This type of fastening element has a tip in the form of a drill with 2 feathers. Used for fastening metal up to 2 mm thick. Can be used to attach elements to metal or plastic. Suitable for interior and exterior work.

It can be either galvanized or with a painted head. The head can be equipped with a press washer.

Powder paint is used for painting; all colors are available according to the RAL table. However, in terms of their qualities, especially for outdoor work, galvanized ones are more durable.

Table 2. Dimensions of roofing screws for metal with a drill