Different Types of Fasteners and Their Uses

Hello friends, Today's topic is related to fasteners, in which we will know in detail about different types of fasteners and their uses.

Fasteners are very important in any industry to join one part to another part. 

There are so many different types of fasteners used in the industry as per requirement which we will know further in detail.

In a machine, some parts can be permanently fixed while some parts are temporary because they need to open and close. 

So that we can use different types of fasteners.

Generally fastening is a process used for holding together two parts of a machine or a structure whether temporary or permanent in other words we can say that it has helped to assemble and disassemble the parts as per requirement.

Such as Lathe machines, Drilling machines, and much more.

Different types of Fasteners

Generally, Fasteners can be divided into three categories:

• Temporary Fasteners
• Semi-permanent Fasteners
• Permanent Fasteners

Temporary Fasteners

These fasteners are easy to allow unfastening of the parts connected without damaging the full elements.

Some components are used for temporary Fastening which is as follows:

• Bolt
• Screw
• Nuts
• Washer
• Stud
• Pin
• Keys

See in figure different types of temporary fasteners which are described below in detail.

Temporary Fasteners

Bolt

Bolt has a solid head at one end and is fitted with a thread at the other on which washer and nut are placed to secure it.

The important types of bolts are

hexagonal-headed bolt, square-headed bolt, round bolt, cylindrical or cheese-headed bolt, T-headed bolt, eye bolt, hook bolt, foundation bolt, and countersunk-headed bolt.

Bolts are basically used to join one flange to another flange, parts of the machine, etc.

Screw

A screw is one of the types of fasteners which is generally used to join the thin sheet or metal.

Screwdrivers and wrenches are used as common tools to tighten them.

According to the shape and uses, screws are of different types such as cap screw, collar screw, shoulder screw, etc.

 Nuts

A nut is a device that is used with a bolt or a stud bolt to join and tightened two or more parts together temporarily is called a nut.

It is a special shaped material used to lock the bolt.

The common types of nuts are hexagonal nut, square nut, flange nut, cough nut, capstan nut, ring nut, knurled nut, fly and lock nut, etc.

Note: The bolts and nuts are always opened and tightened by different types of spanners.

Washer

A washer is used in between Bolt and nut to give a smooth bearing surface and increase surface contact area by which loading between bolt and nut decreases.

The washer also prevents the nut from cutting into the metal and this allows the nut to be tightened to a greater extent.

Stud

A stud is like a screw but it does not have a head.

Studs are used in such places where a component is assembled or de-clamped very often.

Studs come in the following types; plain, collared, square cross-section plain, hexagonal socket head studs, etc.

Pin

A pin is normally a rounded piece of metal that joins two separate, hinged objects together. 

There are many types of pins such as solid, hollow, split, gudgeon and dowel pin, etc.

Keys

Keys are used to locating pulleys or gears on a shaft and prevent relative movement between them. 

The key can be withdrawn, at will to engage the mating components.

According to the key fitting, it is of two types sunk and saddle key.

Semi-permanent Fasteners

All fastening methods, in which fastening may get damaged but not the job. 

This is used whenever a little chance to re-open the joints for example soldering, riveting.

Semi-permanent Fasteners joint can be categorized into three parts which as follows:

• Riveted Joint
• Folded Joint
• Solder Joint

See in the figure all different types of semi-permanent fasteners which are described below in detail.

Semi-Permanent Fasteners

Riveted Joint

A riveted joint is used for joining material like sheets, plates, etc.

In riveted joint Drill or punch method is used to join any sheets or plates.

There are three types of Riveted joints.

• Lap Joint
• Butt Joint
• Caulking and Fullering of Riveted Joint

Lap Joint

In the lap joining method join sheets or plates by overlapping the two surfaces.

The lap joint can be divided into two parts.

• Single row lap joint
• Double row lap joint

Butt Joint

An extra sheet is used to join both of the joining plates or sheets. 

Caulking and Fullering of Riveted Joint

Caulking and fullering of a riveted joint is a method in which joints are done with fine efficiency without any leakage which is known as a leak-proof joint. 

A leak-proof joint is to be made through hammered manually or using a power hammer and the fullering tool is used to spread the ends.

This type of joint is mostly used in steam boilers, air and water storage tank.

Folded Joint

With the help of this method, very thin metal sheets or plates are joined. 

These joints are used for joining the boxes, tubs, crockery, etc.

Solder Joint

Soldering is one of the oldest methods, used for forming a joint.

This is the best method for lightweight

joints. 

Solder is used for the alloy, consisting

of tin and lead. 

The melting point range of this process is from 135 to 325° C.

Permanent Fasteners

This process is done, whenever no chance of

the re-opening of joints.

After disassembling this joint, both the job and fastener get damaged for example welding, brazing, etc.

Following methods are used for permanent fasteners:

• Brazing
• Welding

See in figure permanent types of fasteners

Permanent Fasteners

 Brazing

It is such as the soldering but has a stronger

joints.

It is called hard solder. It mainly consists of copper and zinc.

Sometimes silver is used to improve the brazing quality.

Welding

Welding is the process of joining two or more metal parts by melting them up to fusion temperature. 

Pressure may be applied or isn't according to the necessity.

Welding is classified into the following parts

• Plastic or Pressure Welding
• Fusion or Non- pressure Welding 

Plastic or Pressure Welding

In this process, joining ends are heated upon melting point then pressure to fix ends. So that filler metal is required.

Fusion Welding

This welding is also known as non-pressure welding. 

In this method, metals are heated upon the melting point.

And in this process, there is no need to applied pressure.

Assembly Techniques

Assembly technique is a combination of methods, which are used for assembling the machines, their parts, and equipment.

The assembling is a process by which the different parts of a machine are assembled together to form a unit.

The various types of assembly techniques are discussed below:

• Aligning
• Bending
• Sealing
• Fixing
• Thread Cutting
• Jointing

Aligning

Aligning is a process in which we arrange the components in a straight line to improve the work accuracy. 

Generally, it is necessary for shafts in machines because without alignment machine shafts can not work properly.

Bending

When the force is applied at a point or part of an object, then the object changes its shape into a curved or angular form from the straight form or vice-versa, then the process is known as bending.

Sealing

Mechanical Seal is a device that is used in any machine or equipment to prevent leakage. 

Generally, this type of seal is basically used in rotating type equipment like a pump, mixer, blower, and as well as compressor.

A mechanical seal must contain four functional components, which are as follows. 

1. Primary Sealing Surface
2. Secondary Sealing Surface
3. Actuation
4. Drive

Fixing

Whenever a job is to be held at a position for a specific time, the fixing process is used. 

In fixing, a workpiece is held tightly to perform an operation.

E.g., A fixture is used to hold the job which is designed based on the shape of the worktable and job as well. 

Thread Cutting

Thread cutting is a process that produces a groove cutting around a cylinder or any bolts, studs, etc.

This is done by taking successive light cuts with a thread cutting tool bit of the same shape as the thread form.

Jointing

Jointing is a process used for holding together two parts of a machine or a structure.

It also helps to disassemble the parts as per the requirement.

By this process, we can assemble the mechanical parts with each other.


So, friends, I hope you all clearly know about different types of fasteners and their uses also get to some idea about assembly techniques.

FAQ for Fasteners

How many types of fasteners?

Fasteners can be divided into only three categories temporary fasteners, semi-permanent fasteners, and permanent fasteners which are further divided into different types such as bolts, nuts, screws, riveted, soldered, welding, etc.

Which is not a temporary fastening process?

Riveted joint, folded Joint, soldering, welding, brazing is not a temporary fastening process.

What is the difference between temporary and permanent fasteners?

The temporary fastener allows the connected parts to be opened without damaging the complete elements, while the permanent fastening process is performed when the joints do not need to be re-opened.

Which fastener is semi-permanent?

Rivet joint, solder Joint and folded Joint are semi-permanent fasteners.

Which fastener is a temporary fastener?

Nut, bolt, washer, screw, stud, pin, keys, etc are temporary fasteners.

Which fastener is a permanent fastener?

Welding and brazing are the permanent fasteners.