Foundation bolt - a kind of fasteners

In modern construction a hugequantity of various hardware products. It is unthinkable to do without the longest special fasteners, which is called the "foundation bolt". He has another, less popular name - "hairpin".

General information about fasteners

In its construction, the foundation bolt isA round rod of great length, made of steel. At its ends there is a thread intended for one of the sizes of nuts. Various types of steel are used for the production of these hardware products. They can easily be identified by the marking applied to this fixture. The parameters of foundation bolts are regulated by GOST 24379.1-80. It indicates the type, length, execution, diameter and thread pitch, steel grade. There are also detailed descriptions and drawings of various elements of these fasteners.

Depending on the nature of the load and the size, the type of foundation, the supporting structure, these bolts differ according to different criteria:

• by operating conditions: rated (power) and structural (lightly loaded);
• by design;
• by the method of installation: mortgages and deaf;
• by the method of anchoring in the foundation - pinned to the base during its manufacture, on the glue, on the cement-sand mixture, wedged.

Application area

A foundation bolt can be used veryvariously. Most often it is used to create reinforced concrete structures of complex configuration. With the help of foundation studs, strong connections with fixed bases are created. So widespread practice of using this fastener for installation of large equipment (machines, conveyors). This is due to the very large length of the studs and the threaded connection. These features of foundation bolts make it possible to create a fastening that perfectly resists small dynamic loads in the form of vibration of electric motors.

Types of foundation studs

According to GOST all these fasteners are divided into 6 types. The foundation bolts are of different lengths and have different thread sizes at their ends. Depending on their design, they can have different fasteners to the base. Below are the most common types of this type of anchorages:

• The bolt is curved. It can be of two subspecies: a straight rod before bending or bent at an acute angle (15-30 degrees). Fasteners of the second type can withstand heavy loads.
• Bolt compound. It can be of two subspecies: with nuts according to GOST 5915-70 and GOST 10605-72. These bolts can be enlarged in length. The build-up is carried out by means of a steel clutch screwed into the fastened part of the fastener.
• Bolt with an anchor plate. There are three types. The first two differ upper nuts, and the third has a special shaped anchor plate.
• Bolt removable. This fasteners are of three types. All of them differ between themselves with anchoring armature and an external nut. Removable fasteners can be virtually any length. This feature explains why the anchor foundation bolts are so popular. GOST 24379.1-80 provides for 3 types of performance of such fasteners. They differ in envy of the diameter of the thread. Fundamental anchor bolts are most often used in securing equipment. They allow you to easily and simply mount or dismantle any machine.
• Straight bolt. This type of fasteners is considered classic. Its lower edge can be welded simply to the reinforcement of the reinforced concrete structure before it is poured with concrete.
• Bolt with conical end. It differs from other types in the shape of the end of the hardware, which is attached to the base. It has an expanding conical shape. Thanks to it, the foundation bolt is firmly fixed and it is simply impossible to pull it out of concrete. There are several varieties of this type of fasteners.