12 DIFFERENT TYPES OF FASTENERS | THEIR USES & EXAMPLES
In this article, you’ll learn what are different types of fasteners? How to Use? Explained with fastening methods and examples. Download the PDF file of this article at the end of it.
What are Fasteners?
Fasteners are several parts of any machine whether it is big or small. These parts are joined in different ways according to their role and position in a machine.
Such holding devices as nuts, bolts, screws, keys, washers, rivets, anchors, studs, inserts, rings, and pins are called fasteners. The process of holding together the different parts of a machine is called fastening. Fastening can be of three kinds.
- Temporary fastening
- Semi-permanent fastening
- Permanent fastening
1. Temporary Fastening
When parts of a machine are joined in such a way that these can be disjointed or joined again easily, it is called temporary fastening. There is no harm to the machine or its parts in temporary fastening.
In temporary fastening nut, bolts, screws, lock pin, and washer are used. These things are called fasteners. The main temporary has been explained later in the article.
2. Semi-permanent Fastening
In a semi-permanent fastening method, the fastening may be destroyed but not work. It is used when the joints have had little chance of re-opening. Such as soldering, riveting.
3. Permanent Fastening
They are single-use fasteners designed to be a permanent joint between two materials or parts. When a permanent fastener is used, the parts will never come apart. The example of permanent fasteners is rivets, welding, soldering, and brazing.
Types of Fasteners
Following are the types of fasteners:
- Key and key-ways
- Retaining rings
- Clevis Pins and cotter pins
It is a small block of metal or other material commonly square or hexagonal in shape. It has internal threads to receive a bolt. Bolts are mostly used with the help of nuts. According to their working position.
This is one of the widely used fasteners. Bolt is made from a thin rod of metal. On its upper side, different types of heads are made to fix them. On the remaining part or a part of it, there are threads. From this side, it can be fixed in a job or a nut can be fitted figure shows a nut and a bolt.
Screws are used for joining different parts of machines. Different types of threads
are cut on screws. A screw may be considered as a helix wound around a cylinder.
Their diameter is comparatively smaller than bolts. Their diameter is up to about 1/4″. The heads of the screws are of different types. The screw is mainly divided into four parts.
Its shape is like a round ring. Before tightening the nut and bolt, it is fitted on a stud or bolt. It is used to ensure the tightness of a joint, screw, etc., and make it easier to unscrew the nut and bolt and keep their threads secure.
Even if the diameter of the bolt in which the bolt is to be fitted is larger than the diameter of the bolt, with the washers help nut bolt can be tightened easily.
#5 Key and Key-ways
A key is a machine element that connects a rotating machine element to a shaft and enables torque transmission. The key helps to prevent relative motion between two parts. As the below figure shows, the shaft must have a keyway to fit the key on it.
With the help of a key, gear or pulley cannot move on their shaft but the shaft and gear or pulley move together as one unit. A key is inserted between a shaft and a wheel in the keyway.
This makes the shaft and gear or pulley (or we can use the term “wheel”) one unit. Keys are generally made of good quality steel in order to withstand (bear) the stresses.
It can be termed a headless bolt. Stud is a relatively long rod that has threads on both ends, the threads may extend along the complete length of the rod. First, the stud is tightened in the hole of the part to be joined with it and then a nut is tightened on it.
Its main advantage is that we can separate the upper part simply by opening the nut while keeping the lower part intact. These studs are mainly of the three types.
In the round stud, the middle portion is also round. In square stud, the middle portion is kept square. The third type is a collar is made at a little distance from the center. It is often used in the cylinder head in automobiles.
In order to joint the jobs made of sheets or plates permanently these rivets are used. In the boiler and sheet metal work, it is used for making trunks and buckets.
Rivets are usually made of mild steel but sometimes they are also made of brass, copper and aluminum, etc. The rivet consists of only three parts, which are head, shank or body, and tail.
Anchors are types of fasteners, their function is similar to the anchor of a boat, which inserts itself into the seabed to prevent the ship from moving. Typically, it is used to attach something to a material such as drywall or concrete. They insert themselves into the material and keep the object you are affixing.
It is a small metal spike with a wide flat head, which is pushed into the wood to hold things together or used as a hook. Nails have been used since the early years and they have now become a household item.
You can easily understand the difference between a screw and a nail because a nail does not have threading on its body. The different types of nails take their names from their applications, which can help you find the right type of nail for the job you are looking for.
These are the type of strong threads and are usually cylindrical in shape also known as thread bushings. They are used for many applications such as securing long-lasting connections between different materials or repairing stripped threads.
The typical application of this fastener is to distribute loads from the smaller diameter of the screw to the larger diameter of the insert.
#11 Retaining Rings
The retaining rings are types of fasteners used to hold shafts or assemblies in place. They usually design in different shapes. They are used in many applications in machinery.
An example of a retaining ring, which is used to hold the latch pin of an IC engine piston. In addition, it is also used to hold the assembly together in the high-pressure fuel pump of a diesel generator.
Most retaining rings are one-time use and replaced when machinery is repaired but some can be reused.
#12 Clevis Pins and Cotter Pins
These are types of fasteners, which are further manufactured from steel pins or with a cylindrical shaft. These have a hole in the shaft into which a cotter pin is inserted and bent to act as a staple. These are used to keep the components of machines in precise position or alignment.
Advantages of Fasteners
Following are the advantages of fasteners:
- Using fasteners will reduce the weight of the component.
- They have the ability to achieve high-strength steel up to a tensile strength of 1500 MPa.
- Fasteners require minimal space within the appliance.
- The equipment maintenance of fasteners is easy and simple.
- They are easy and simple to install in every working place.
Disadvantages of Fasteners
Following are the disadvantages of Fasteners:
- If you are using fasteners, this will increase the weight of the component.
- They usually require holes to fit a fastener that weakens the components.
- They are able to work at specific points in all types of loads, which will lead to fatigue.
- Once fastened, it is difficult to fasten again.
- They are often lead to corrosion.
Wrapping It Up
With the wide variety of fasteners available today, it becomes challenging to choose the right fastener for your application. We have almost covered the different types of fasteners and their uses in this article.