How does a bolt differ from a screw and a screw and what are they for?
Screws, screws, screws, bolts and nuts are all combined under one name “construction fasteners” or, in a different way, “hardware”. Their main task is to fasten various parts of industrial and domestic structures. Depending on the specifics of production and destination, all fasteners have their own characteristics.
The most common part among all connecting elements having a thread is a screw. It is worth starting with it the distinctive characteristic of all threaded hardware, in order to understand the difference between a screw and a bolt and a screw.
What does a screw look like and how does it differ from a bolt
In principle, the screw is a small bolt, but, as a rule, its head is not multifaceted, like a bolt, but has a slot (a cutting hole) for a screwdriver. Since bolts are threaded on the head, especially if they are small, there is one more difference by which you can understand the difference between a bolt and a screw.While the main clamp of the bolt is a nut, its counterpart - the screw - is fixed inside the part by a thread specially provided for on the fastened part without additional fasteners. If there is no nut at the end of the fastener, then we have a screw.
Thanks to the above, the screw can be used in those places where access from the back side is closed. For example, covers and plugs in various designs, mechanisms, household and industrial products.
Screws are made from a wide variety of metals: mainly steel, but for electrical equipment they are stamped from bronze, copper, and brass, when they are not simply fastened to parts, but also conduct electricity well.
What does the screw head look like?
Head screws come in a variety of shapes:
- in the form of a truncated cone.
And it is even not always possible to understand the difference between a bolt and a screw, because the head of the latter may be multifaceted, which is mostly the case with large-sized screws used in mechanical engineering.
The sections on the heads (slots) are complete, for flathead screwdrivers, and incomplete, for crossheads.But now often make universal heads with a full cross-section, supplemented by a crosspiece.
What is a screw and what is different from the screw
The self-tapping screw is a kind of screw, but with a pointed end and sharper thread. His main task is to make the thread inside the fastened part. The most common product of such a plan for builders is a black screw.
Self-tapping screws are made for fastening products from various materials, but basically they are divided into two types:
- for woodworking;
- for work on metal.
The main difference is the frequency of the thread.
What distinguishes the screw from the screw
The pointed tip of the screw is hardened during the manufacturing process in order to give it greater strength compared to the screw. This is their main difference, because when they are screwed into parts with screws, there is a drilled hole, and when using a self-tapping screw, the hole is punched through the fastener itself.
But the screw itself is a type of screw. And the difference between them is in a wider thread pitch and a pointed tip. Often the screw is used with dowels, for connection with hard but crumbling materials, such as concrete, brick, gas silicate.
What does a bolt look like and how does it differ from a screw
As mentioned above, in order to clearly differentiate between the bolt and the screw, the definition of each of them must be made according to the method of fastening. So, the nut is used as a fixing element for the bolt, and the screw is directly twisted deep into the fastened parts and has a counter thread in the second one. The nuts must have the same size of the threaded hole as the bolts, otherwise they will not fit.
It is always possible to clarify what design is in hexagonal bolts, and determine the difference between a screw and a bolt, according to GOST 7805-70. It is this document that regulates the production of these parts and their qualitative and quantitative characteristics.
Most often, universal bolts with full thread are made, but there are also variants with incomplete ones - for fastening flat parts of large thickness. By the principle of fastening it is also possible to understand the difference between a bolt and a screw. After all, when using a bolt, always its second end comes out of the fastened part and is fixed with a nut, while at the screw it hides inside the part. When considering the design features already mentioned,the difference between a bolt and a screw, and it is for this difference that bolts are designed to connect two flat parts, and screws - for a flat part with products of any thickness.
Bolts, moreover, when fastened with a nut under the influence of vibrations or when joining wooden parts, tend to self-unscrew. To prevent this, put a locknut on the bolt (the second after the first one) or use self-locking nuts.
In order not to damage the bolt with a soft material, such as wood or plastic, and so that the fastener does not push the soft material under load, a washer is placed under the head of the bolt. For more reliable connections use two washers, placing the second under the nut.
Stud as a type of bolt
The hairpin is a core on which the thread is applied either along the entire length or at its ends. It is fixed in the same way as the bolt, with nuts. A hat is the only thing that a bolt differs from a stud in. From the screw, they are distinguished precisely by the method of fixation directly between the structures.
Studs are used mainly for fastening of suspended air ducts, ceilings and other structures. The average length of this part is 5 cm, but in the industry one can find such fasteners up to 2 meters long.