Features of metal dowels

When performing installation work, a special fastener is often used - a dowel-nail. It is called so for a reason - its design assumes a cylinder hollow inside with side loops, as well as a nail inserted into it. There are several options for such hardware - they are used to work with dense materials and porous bases. In this article, we will consider the features of metal dowels.

From a technical point of view, any dowel-nail includes several structural elements - the dowel itself and the nail. The dowel looks like a metal cylinder with prefabricated elements located on the sides. When the nail is inserted into the cavity, they begin to straighten, thus ensuring the most durable fastening of the parts in the base. The outer part is complemented by a small cuff. It prevents the entire nail from falling into the inner cavity of the base.

The thread in the nail of the hardware is applied asymmetrically, this excludes the occurrence of obstacles for its introduction into the dowel. However, it does not allow it to be pulled out later, such a dowel can only be unscrewed. For this, a slot for a Phillips screwdriver or a screwdriver is fixed on the head.

Fasteners made with steel nail dowels are very difficult to dismantle. They lead to a long operating period. The most reliable fixing strength can be achieved when working with hard as well as corpulent materials. Among the main advantages of a metal dowel-nail, the following are distinguished:

• increased bearing capacity;
• long period of service;
• resistance to high humidity and temperature fluctuations;
• resistance to rust.

An undoubted advantage can also be called the breadth of the assortment - in modern stores there is a large selection of dowel-nails for any occasion. However, it was not without its drawbacks. So, there are certain restrictions and requirements for the technique of work, since the fasteners create a noticeable stress in the base. In addition, metal hardware is more expensive than their plastic counterparts.

For fixing various materials, it is necessary to choose an appropriate size dowel-nails. Its marking contains 2 numbers, for example, 5x30 - the first of them shows the diameter of the attachment, and the second shows the size of the hardware itself in millimeters. The most popular are hardware of the following standard sizes:

• 5x25, 5x30, 5x40;
• 6x30, 6x32, 6x49, 6x35, 6x40, 6x50, 6x60, 6x70;
• 8x80, 8x50, 8x60, 8x80, 8x100, 8x120, 8x140;
• 10x80, 10x100, 10x120, 10x130, 10x140, 10x160.

Any types of fasteners have their own limitations on the ultimate load, so the selection of the length directly depends on the size of the material to be fixed. So, a dowel with 6x40 parameters will be a good solution for fixing the profile in efficiency buildings, where walls and ceilings do not provide for cavities. For brick blocks, dowel-nails of the size 6x60 or 6x80 are optimal.

Dowel-nails are classified depending on the characteristics of the bearing surface. In particular, for solid porous concrete, hardware of the M150 brand will be required - it is characterized by a special relief and includes a pair of spacers, additionally they provide a self-tapping screw or a threaded stud. Aerated concrete hardware is equipped with wide-pitch spiral ribs. They are optimal in the case of a large area of ​​contact between the hardware and the hole. For drywall, concrete and many other porous materials, the choice is best made in favor of products equipped with spiral threads.They usually have a twist drill at the end, which allows fixation to be carried out without preliminary hole preparation.

There are the following types of nails for hollow bases:

• Molly - a distinctive feature lies in the release, which provides a strong fixation of the drywall; the maximum load on each hardware reaches 30–35 kg;

• butterfly - a lightweight and simplified version of steel hardware, contains plastic elements;

• umbrella - includes spring-loaded plates that open up in voids after their installation;

• Driva - similar to hardware intended for work with porous concrete; the maximum permissible load is 25 kg, the length of these dowel-nails does not exceed 44 mm;

• frame - has a considerable length and a wide spacer part;

• adjusting - optimal for fixing the frame and its guides.

There are also self-tapping and wedge hardware. According to the installation technique, the hardware is divided into those installed with a construction pistol, as well as driven ones. To fix the anchor-type hardware, you need to place the pistol in the area of ​​the intended attachment and "drown" the trigger. At the same time, there is no need to drill holes and this greatly reduces the total time of repair and installation work, and in addition, eliminates the formation of construction dust in the room, which usually appears when using a drill and screwdriver. At the end of such hardware, a thickened rod is provided; a lock washer is attached to it. The inner nail provides for a large hat, it does not allow the hardware to sink into the building material. It is important to keep in mind that such fasteners cannot be reused.

From the point of view of functional purpose, this category also includes a brass dowel-nail. Its fixation is carried out by screwing it into the drilled holes. A distinctive feature of such products is their anti-corrosion characteristics, which determines a wide scope of their operation. The functionality of the driven dowel-nails varies depending on their dimensions. Most often, their length ranges from 25–70 mm. Such a choice of dimensions allows hardware to maintain the versatility of fastening not only for loose bases, but also for harder surfaces. The lack of strength of loose bases is compensated by a smaller pitch between fasteners.

When buying metal dowel nails, the following important criteria must be taken into account:

• base material parameters - in solid structures, the strength and strength of fixation directly depends on the friction force, and in porous structures - on the dimensions and shape of the fasteners;
• features of the material of the dowel itself and the self-tapping screw - it is better to give preference to hardware made of the same material;
• head view - for the correct distribution of the load, it should be remembered that the contact of the head with the plane of the mounted structure should be maximum;
• maximum permissible load - this parameter is usually indicated in the certificate and user manual; in accordance with the regulations, the work load is 30% of the maximum.

The technical and operational properties of universal hardware make it possible to use them everywhere for attachment to planes made of such building materials as:

• cellular concrete;
• concrete;
• plaster;
• GKL;
• hollow brick.

Such hardware has become widespread in the implementation of construction and finishing works. The parameters of using one or another hardware are determined by the characteristics of the base, the number of fasteners, and also their type depends on the technical features of the installation. The following points are usually taken into account:

• type of fastener;
• material;
• place of installation;
• work load;
• axial distance.

The scope of use of hardware is quite wide - they are universally in demand when arranging stretch ceilings and all kinds of metal frames. Dowel-nails are irreplaceable when performing thermal insulation of external facades and internal walls of the house. Features of fixation on solid bases allow using these hardware for wall cladding with insulation and cladding panels. Fasteners designed for fixing with a construction gun are quite convenient to attach metal structures to a wooden or concrete base. It is no coincidence that this dowel is often used when fixing metal canopies over balconies, loggias and windows.

In the next video, you will check the fastening of a metal dowel in a piece of aerated concrete.