Eye bolts: rules for selection and application

Swing bolts are a popular type of quick-release fasteners that have an original design and a rather narrow range of applications. Their dimensions are standardized by the requirements of GOST or DIN 444, there are certain restrictions on the material of manufacture. Let's take a closer look at how to choose a swing bolt, and which types to prefer for solving specific problems.

A pivot bolt is a metal product that provides a threaded connection of elements. It is made of alloy steel, anti-corrosion A2, A4 and other alloys (brass, bronze) with increased strength sufficient for operation under load. There are also galvanized hardware for use in a humid environment. In the design of the product there is a rod equipped with full or partial thread, the tip is supplemented with an eyelet that replaces the head.

The production of swing bolts is standardized in accordance with GOST 3033-79. According to the established requirements, metal products must meet the following characteristics.

• Thread diameter - 5-36 mm.
• The length should be 140-320 mm for products with a diameter of 36 mm, 125-280 mm - for 30 mm, 100-250 mm - for 24 mm, 80-200 mm - for 20 mm. For products of smaller dimensions, the indicators are more modest: they vary in the range from 25 to 160 mm.
• Head type. It can be spherical or forked, as well as in the form of a ring.
• Length of the thread cut. Usually ¾ of the length of the rod.
• Thread pitch. It starts from 0.8 mm, for products larger than M24 it reaches 3 mm.
• Section of the ring. Varies in the range of 12-65 mm.

Swing bolts or DIN 444 with an eyelet are available in a wide range of standard sizes. The most popular options are M5, M6, M8, M10, M12. Products made in accordance with GOST 3033-79 are also in demand in a large-format version, they can reach the size M36. The main difference between the standards is the use of recommended materials.

According to DIN 444, it is allowed to manufacture metal products from carbon steel with or without galvanized coating. For bolts operated in an alkaline environment, stainless A4 Steel is used, suitable for use in the food and chemical industries. Austenitic steel hardware is suitable for use in sea or salt water environments. Brass can also be used.

According to the standards, the following types of eye bolts are allowed.

• With round / ball head. A rare option that allows you to provide a clamp-type connection. When fully screwed in, a reliable lock is obtained, which can be easily dismantled if necessary.
• With a hole for a cotter pin. The most common option. This swing lock set bolt is suitable for making cotter pin connections. They can also attach carabiners to the structure if rigging is required.
• With fork head. It is similar to conventional ones, but has an additional slot that allows the use of hinged mountings.

Depending on the type of design, the swing bolts can be screwed in using the corresponding lever elements. In a rounded eyelet, this role is usually played by a metal rod of the corresponding diameter. In addition, flat levers can be used for products with an elongated profile.

There are certain guidelines for choosing the right eye bolts for use in a variety of activities. Let's highlight several important parameters.

• Material type. Classic steel products are designed to work outside high humidity environments. For damp rooms and outdoor use, nickel-plated and stainless steel bolts are used. Plastic elements are considered household items, they are not designed for serious loads, but they can easily withstand clotheslines. Bronze and brass products are used in ship structures.
• Thread length. It affects not only the strength of the fastening, but also the dimensions of the protruding functional part. For rigging and other carabiner attachments, 3/4 thread designs are best. For cotter pin connections, other options are more suitable for creating a clamping force. In them, the thread is located along the entire length of the rod.
• Standard sizes. They determine the load that a metal product can withstand, and also affect the purpose of fasteners. Most of the household varieties are marked M5, M6, M8, M10, corresponding to the thread diameter in millimeters. You need to focus on the size of the hole used and the characteristics of specific bolts.
• Corrosion resistance. The higher it is, the more aggressive contact with the external environment the product can withstand. Outdoors, only galvanized or brass options are used, which are not afraid of corrosion.

These are the main parameters that you should pay attention to when selecting eye bolts for home use, during rigging or during construction.

Swing bolts are an indispensable fixing element for rigging. They are used when loading, lifting bulky cargo, acting as an element for fixing carabiners on the surface of a platform, container, box or other type of container. In the bridge building area, strings of cable-stayed structures are installed and held with the help of such fasteners.

This type of hardware is also in demand in industry. Special heat-resistant options are used in furnaces where firing is performed at high temperatures and pressures. In milling and drilling machines, they often act as quick release fasteners, ensuring a secure hold during use. Mostly, you can see the hinge bolts on the pulley covers that block access to the replacement spindle. For industrial purposes, metal products manufactured in accordance with GOST 14724-69 are used.

In the furniture industry, hinged fasteners are used to generate the downforce. When transporting hazardous substances, it is installed to press the lid in order to exclude contact of the transported substances with the external environment.

In everyday life, this type of fastener also finds its application. First of all, it is used for tensioning various rope and rope structures. Self-made clothes drying devices are fixed precisely with a swing bolt or screw of the same type. The metal product adheres well to concrete and wood, suitable for use in bathrooms, if a galvanized version is chosen.

Besides, eye bolts are well suited for use in various designs in the garden and in the courtyard of a private house. With their help, you can hang a tent roof on stretch marks, make a temporary canopy from the sun, and strengthen a garden swing. There is no need to pre-prepare the fasteners, to combine them: the structure is already ready for use, it is enough to simply install it in the chosen place. This is useful for seasonal use of the hammock. At the end of the time of use, it can be removed and then hung up again.

See the following video for the production of eye bolts.