No construction or production facility is complete without fasteners. They are used when fastening small parts and when fixing large blocks experiencing serious stress. Depending on the purpose and scope of application, fasteners are divided into categories. The state standard, however, describes only a small part of what is on the market.
There is a generally accepted classification system for fasteners:
- High strength threaded products;
- Fasteners for mass use;
- Fasteners for shockless fixation and one-sided mounting;
- Elements for sealed structures;
- Clamps required for fixing polymer composite materials.
There are several more types of classification. For example, by construction type. There are two sections here:
- Detachable – That is, all fasteners consisting of two or more parts.
- And one-piece, such as nails and rivets.
Bolts and screws
Bolts and screws are classified as heavy duty threaded fasteners. They are also often referred to as detachable types, which is not entirely true, since both the bolt and the screw can be twisted into the nut and into the thread already on the fastened product. It is believed that the main difference between a bolt and a screw lies in the type of fastening: the bolt works exclusively in tandem with the nut, and the screw is screwed into the finished thread. This is an incorrect statement, since the state standard number 27017-86 defines that both the first and second type of fasteners can be used both in tandem with a nut or without it.
Since the screws work under heavy loads, the design of their head is most often shaped like a screwdriver. In this case, the form may differ, and very significantly. There is a certain classification of headboard forms: Flat, Round, Mushroom, Secret, Semi-secret, Convex.
The types of splines also differ, and here everything is much more complicated, since many fasteners manufacturers in India use their own design. But, the most common shape of splines is a cross, straight and hex.
Bolts, due to their classification and standardization, are less diverse. Their headboard is most often hexagonal, designed to be screwed in with a wrench, but there are also varieties for a screwdriver. The main area of application of bolts is fixing elements using the clamping method. They create a reliable connection on both sides, and resistance to stress is determined by the thread pitch and the size of the hardware.
Screws and screws
These two types of fasteners can be categorized as they are similar in design and application. In fact, a self-tapping screw is the same screw, but in a modern design and with a number of advantages. So, to fix it with a screw, you must first drill the hole, and only then screw in the fasteners. A self-tapping screw, in some cases, itself copes with the task of drilling and is screwed in without additional preparation of the seat. The screw, even made of hardened steel, does not have a sharpening on the thread, therefore, even using it to connect two wooden elements, you must first prepare them.
The assortment of fasteners is extensive and not all types of fasteners and areas where they can be used are described here. Entering any store or any other city, you will see completely non-standard products, for example, bolts with a ring. They are used for suspensions. Or custom-shaped anchors. The choice of fasteners depends on the task at hand, but it is equally important to find a worthy manufacturer. Dozens of companies are engaged in the manufacture of custom-made fasteners, and not all of them can boast of the high quality of their products. It is not difficult to buy fasteners, but can the manufacturer guarantee the quality and reliability of the product? The store, as a rule, is not responsible at all.