Advantages and disadvantages of extrusion

Extrusion is a common manufacturing process used to create objects of a fixed cross-sectional profile. It is one type of forming process. Although this process is widely used and with many advantages, it also comes with some disadvantages too which we will be discussing here. 

Advantages of the extrusion process:

1. Extrusion is a continuous high production volume process. 
2. It can easily create complex shapes too. 
3. This process can be used for both brittle and ductile materials. 
4. Lower cost per parts manufacturing. 
5. This process working operation is easy and flexible. 
6. Good mechanical properties and surface finish obtained especially in cold extrusion.
7. Good compounding and efficient melting are achieved by this process. 
8. No oxidation takes place in this process.
9. Superior dimension control. 
10. Uniform product produced by this process. 
11. Better grain structure and accuracy achieved in this metal forming process.  
12. Less wastage of material in the extrusion process. 
13. Required low deformation energy.
14. Economical for mass production.

Disadvantages of the extrusion process:

1. For deformation high compressive force required. 
2. High set up cost. 
3. Only one type of cross-section can be obtained at a time thus product limitation. 
4. Sometimes the product expands more due to unequal force applied thus variations in the size of the product. 
5. Close tolerance can not be held. 
6. High temperatures may promote undesirable cause thus heat resistant tools are required which are expensive. 
7. Extrusion dies easily wear out. 
8. Thermoset plastic is not suitable. 

Explore more information: 

1. What is Extrusion? | Classification | Working Principle | Extrusion Ratio

What are the disadvantages of muff coupling?

Muff coupling is also called sleeve coupling is the simplest type of rigid coupling that consists of a hollow cylinder. Whose inner diameter is the same as a shaft. It is fitted over the ends of two shafts by means of gif head key and power transmitted from one shaft to another by means of a key and a sleeve. Now, let us have a deep insight into the disadvantages of muff coupling in this article. 

Disadvantages of muff coupling:

• Muff coupling is difficult to assemble or dismantle.
• It is a rigid type of coupling and requires accurate alignment of shafts.
• It can not absorb shocks and vibrations because there are no flexible parts.
• This coupling is used where the motion is free from vibrations.
• It requires more axial space compared with flange coupling.

Automobile full form list | Automobile Acronyms

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Full form of DSLR

What is the full form of DSLR?

Answer :

• Digital Single Lens Reflex

What does DSLR mean?

It can be used to take high definition quality pictures with uses light travels through the lens, then to a mirror that alternates to send the image to the image sensor.

It is a combination of optics and the mechanism of SLR with a digital imaging sensor.


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• CNC full form

• VMC full form

• CAM full form

• SFC full form

• CRDI full form

• TDI full form

• TCI full form

• PDI full form

• ESC full form

• LASER full form

• ARAI full form

• VTVT full form

• DFI full form

• GVWR full form

• HVAC full form

• IHP full form

• ISFC full form

• KPL full form

• OHV full form

• FHP full form

• LPG full form

• EBD full form

• BHP full form

• BMEP full form

• BSFC full form

• CDI full form

• CI Engine full form

• CV full form

• NHTSA full form

• IMEP full form

• ESC full form

• 4WD full form

• CNG full form

• TC full form

• VDB full form

• VVT full form

• 2WD full form

• FPEG full form

• Kph full form

• CC full form

• CCVTI full form

• CVTI full form

• LCV full form

• HCV full form

• ASFS full form

• APDV full form

• SAE full form

• MUV full form

• SUV full form

• XUV full form

• DTSI full form

• VTVT full form

• MPFI full form

• ABS full form

• SOHC full form

• DOHC full form

Difference between galvanizing and electroplating

Some information on galvanizing and electroplating and their difference are discussed in this article. So now, first of all, we can check out the definition of both processes. Let us check out the difference between galvanizing and electroplating to know more about it. 

What is galvanizing?

The process of applying a coating of zinc to steel to protect it against corrosion is called galvanizing. The entire process is done through immersion of a steel product into a bath of molten zinc. 

What is electroplating?

The process of coating a metal with a thin layer of another metal by electrolysis to protect metal against corrosion is called electroplating. Electroplating is also known as electrodeposition. 

The main key difference between galvanizing and electroplating is given below. 

Galvanizing Vs Electroplating: 

• Galvanizing is specific coating of zinc whereas electroplating is various options of metal for coating. 
• Galvanizing is done just by dunking steel into molten zinc so no electricity is required while electroplating requires electric current. 

Difference between anodic and cathodic coating

Information on anodic and cathodic coating and their difference between them is given below in this article. Coatings are coating applied on metal to protect the metal and reduce the wear and tear. 

What is the anodic coating?

As we know the anodic coating is a type of coating material that uses anodizing to provide aluminum or any type of subtraction with increased thickness, color, and protection. This coating consists of the oxide film formed by electrolysis on metal, with the metal acting as an anode.

What is a cathodic coating?

While in the cathodic coating is a technique that reduces the corrosion of a metal surface by making that entire structure of the cathode of an electrochemical cell- that is the derivation of the term. This is typically accomplished by discharging current from an external anode so that the current flow through the electrolyte to the original anodic sites on the surface of the structure, rather than the aways from it.

The cathodic coating often classified and also known as electrophoretic deposition, e-coating, electrocoating, cathodic electrodeposition, anodic electrodeposition, electrophoretic coating, and electrophoretic painting. 

The main key difference between anodic and cathodic metal coating is given below. 

• Anodic means positively charged conductor and cathodic means negatively charged conductor.
• In anodic coating the base metal is coated with metal which is anodic to it, it is called an anodic coating while in if the base metal is coated with metal which is cathodic to it, such a phenomenon is called as a cathodic coating.
• anodic coating, it protects the base metal from corrosion while in cathodic coating prevents the metal from getting corroded.
• Anodic coating failure of this coating causes the formation of galvanic cells while in cathodic coating loses its strength, it causes imbalanced cathode and anode and causes corrosion at a severe rate.
• The well-known example of anodic coating is the coating of zinc on iron while the cathodic metal coating is coating tin on iron.

Why flexible couping are preferred over rigid coupling?

Flexible coupling accomplishes the purpose of any coupling, but the main advantage over rigid coupling is flexible coupling is to accommodate the unavoidable misalignment between shafts in some machinery. 

The flexible coupling also allows a degree of axial movement between the coupling shafts as possible due to thermal expansion.  

As compared with a flexible coupling, the rigid coupling has limited application because rigid couplings do not have the ability to compensate for shaft misalignment, therefore, used where shafts are already positioned in precise lateral and angular alignment.


Explore more information:

1. What are the disadvantages of muff coupling?
2. What is coupling?
3. Difference between the rigid and flexible coupling

Proell governor | Construction | Working | Equation of height

A porter governor is known as a proell governor is the two balls are fixed on the upward extensions of the lower links which are in the form of bent links BAE and CDF as shown in the figure below. 

Now, considering the equilibrium of the link BAE which is under the action of following characteristics. 

• The weight of the ball, mg
• The tension in the link AO
• The horizontal reaction of the sleeve
• The weight of sleeve and friction 1/2 (mg+f) or 1/2 (mg-f)
• The centrifugal force, mr’ᾠ² 

I is the instantaneous centre of the link BAE and take moments about I to find out the height relation for proell governor. 

N² = 895×a/h×e [ 2mg + ( mg + or – f ) ( 1+k) / 2mg ] 

Difference between watt governor and proell governor

The function of the governor is to regulate the speed of an engine when there are variations in the load. For example, when the load increases, it becomes necessary to increase the supply of working fluid and when the load decreases, less working fuel is required. Let us have a deep insight into the difference between watt governor and proell governor in this article. 

Difference between Watt and Proell Governor : 

• Watt governor is the simplest form of a centrifugal governor basically a conical pendulum with links attached to a sleeve of negligible weight and the proell governor has the balls fixed at the endpoint to the extension of the links. 
• Watt governor is pendulum-type while the proell governor is dead-weight loaded type governor. 
• The arm of watt governor may be connected to the spindle by two way, the pivot may be on the spindle axis, and pivot may be offset from the spindle axis but arms intersect while in proell governor the balls are fixed. 

Explore more information:

1. Difference between an anodic and cathodic coating
2. Difference between galvanizing and electroplating

Mechanical Vs Hydraulic disc brake | Difference between mechanical and hydraulic disc brake

The function of both braking systems are the same but there is a lot of difference between these two brakes. Mechanical disc brake also known as cable-actuated brakes rely on a braided steel cable to activate the piston that causes the compression of brake pad against the rotor when the brake lever is pulled. Hydraulic disc brake used hydro or rather fluid uses a sealed fluid-filler system as a means of actuation. Let us have a deep insight into the difference between these two braking systems. 

Difference between mechanical and hydraulic brake : 

• A mechanical disc brake uses cables as a braking medium whereas hydraulic disc brake uses the fluid as a braking medium. 
• The mechanical disc brake is heavier in weight as compared to hydraulic disc brake. 
• A mechanical disc brake is less sensitive, requires more force to come to a stop and the hydraulic disc brake is more sensitive and efficient. 
• Maintainance is frequent in mechanical disc brake whereas hydraulic brake is the maintenance free. 
• Adjustment of brakes is easy in mechanical braking while complex in hydraulic braking.
• The hydraulic disc brake is expensive as compared to mechanical disc brake. 
• Hydraulic brakes give better performance for the same size rotor, but mechanical brakes are good enough if you are using a bigger rotor and set them up correctly.

Types of air filter

The air filtration manufacturer has seen its share of changes over the last decade. They have created new products that not only have improved indoor air quality but also have reduced the cost of installation. When the American Society of Heating, Refrigeration, and Air-conditioning engineers introduced IAQ standards for an air filter. Among these several types of air filters are common in common HVAC systems. 

Different types of air filter: 

Fibreglass filter: This is the most common type of air filter. Layered fibreglass fibres are laid over each other to form the filter media and reinforced with metal supports to prevent failure. 

Polyester and pleated filter: This filter is similar to fibreglass filters but typically have a higher resistance to airflow and a superior dust stopping ability. 

Washable air filter: This filter is not common and relies on the build-up of dust along the clothes to improve the efficiency of a filter. 

High-efficiency particulate arrestance (HEPA) filter: Air passing through this filter at a very fine scale. The US department of energy (DOE) use this filter that meets standards. 

Carbon air filter: Carbon can be treated with oxygen, which opens the carbon's pores making it highly absorbent. It uses activated carbon to trap chemicals and gases, and can also filter cigarette smoke. These activated carbon air filters are well suited to an environment where chemical must be removed from the air. 

UV light air filter: This filter use reaction that occurs when titanium dioxide is exposed to UV light. As the air stream encounters the photochemical process, harmful particles, such as mould and bacteria, are neutralized. 


Explore more information : 

• Difference between the air filter and cabin filter

Difference between air filter and cabin filter

Both air filters and cabin filters purify the air but their purpose is slightly different. The air filter cleans the air that flowing to the engine while cabin filter decontaminate air coming into the cockpit. It's important to recognize the distinction between these two filters so in this article you can check it out some difference between the air filter and cabin filter. 

Difference between the air filter and cabin filter : 

• The air filter is often a performance upgrade, while the cabin air filter is more of a health and safety concern. 
• The air filter is located in the engine bay under the hood inside a sealed box and is one of the important components of the engine whereas the cabin filter is located behind the glove compartment, under the dash and under the hood. 
• The air filter prevents dirty air from getting into the engine while cabin air filter blocks dirty air from getting inside the cabin. 
• Some old vehicle with carburettors has a big metal air filter that located in a round, bulky case made of plastic or metal whereas some vehicles have the air filter installed inside the HVAC case between the blower motor and evaporator core. 
• The air filter prevents the bugs, dirt, debris and contaminants from entering the delicate system of an engine and allows the only pure air in and the cabin air filter blocks all the airborne allergens and other pollutants from entering the ventilation system of the vehicle. 
• If the air filter is not replaced and allowed to block up, it can increase fuel consumption and place additional strain on the engine and driveline components whereas failure to replace the cabin air filter may cause a musty smell to emanate through the air conditioning system, and make car trips unpleasant, especially on hot days.
• Due to a bad or clogged air filter, the turbo life of vehicle gets minimized whereas cabin filter only passes to clean air to the vehicle. 

Explore more information : 

• Types of the air filter

Porter Governor | Construction | Working | Equation of height

Porter governor is same as Watt governor. If the watt governor sleeve is loaded with a heavyweight, it becomes a Porter governor. 

Let M = Mass of the sleeve
m = Mass of each ball
f = Force of friction at the sleeve

Porter Governor

The frictional force always acts in the opposite direction to the motion, so when the sleeve moves up, the frictional force acts in the downward direction, and the downward force acting on the sleeve is Mg+f. Likewise, the force on the sleeve will be Mg-f when the sleeve moves down. Depending on whether the sleeve is going up or down, the net force acting on the sleeve is mg+f or Mg-f.

Forces acting on the sleeve and on each ball have been shown in the figure. 

Let h = height of the governor
r = distance of the centre of each ball from the axis of rotation

The instantaneous rotation centre of AB link is at I. It is because of the motion of its two points A and B relative to the link. The point A oscillates about the point O and B moves in the verticle direction parallel to the axis. 

Now, the equilibrium of the left-hand half of the governor and taking moments about I. We equate the equation form given below to find the height of governor. 

N² = 895/h × [ 2mg + ( mg + or -  f ) ( 1 + k ) / 2mg ] 

This equation would provide two values of N for the governor for the same height depending upon the sleeve movement.  

Advantages and disadvantages of worm gear

Worm gear drive is used to transmit power between two non-intersecting shafts, which are at right angles to each other consists of a worm and a worm wheel. The worm is a threaded screw, while the worm wheel is toothed gear. The teeth on the worm wheel envelope the threads on the worm and give the contact between mating parts. Let us have a deep insight into the benefits and drawback of the worm gear in this article. 

Advantages of worm gear : 

• High-speed reduction: A speed reduction is as high as 100:1 can be obtained with a single pair of worm gear. 
• The worm gear is compact with small overall dimensions, compared with equivalent spur or helical gear drives having same speed reduction. 
• The operation is smooth and silent. 
• Provision can be made for self-locking operation, where the motion is transmitted only from the worm to the worm wheel. This is advantageous in application like cranes and lifting devices. 
• The worm gear has good meshing effectiveness.
• The worm gear used for reducing speed and increasing torque. 

Disadvantages of worm gear : 

• The efficiency is low as compared with the other types of gear drives. 
• The worm wheel is made of phosphor bronze, which increases the cost. 
• A considerable amount of heat is generated in worm gear drives, which is required to be dissipated by a lubricating oil to the housing walls and finally to the surroundings.
• The power transmitting capacity is low. 
• It is used for up to 100 kW of power transmission. 
• Lubrication must be strictly maintained for the healthiness of worm gear. 

Difference between welding and fabrication

Welding and fabrication both are two essential processes in the metal industry. In this article, you can check it out the difference between both of these processes so let start with the definition first. 

Definition of Welding : 

Welding is a process which usually involves metals or thermoplastics by inducing melting, which is distinct from lower temperature metal joining processes such as brazing and soldering that do not melt the base metal. Welding is essentially a combination of two pieces, no design, no layout or cutting.

Definition of Fabrication : 

Fabrication is the building of metal structures by cutting, bending, welding and assembling processes. Fabrication is the process of manufacturing or inventing something. Fabrication is making something while welding is only one operation performed during the process. 

Let us have a deep insight into the difference between welding and fabrication below. 

Difference between welding and fabrication : 

• Fabrication of metal refers to the build of metal structures and is carried out through a variety of processes such as cutting, bending, profiling, welding and assembling whereas the prepared metal from fabrication process then welded together using a variety of techniques and methods frequently involve arc, power supply in order to create an electric arc between electrode on the welding rod and the material itself. 
• The difference between welding and fabrication is that welding is a particular method of making something by using heat to join together the metal pieces, and fabrication is creating something and does not usually use heat.

What is drilling? | Types of drills | Drilling operation formula

Drilling is the most common process of machining. The drilling process accounts for nearly 75% of all metal cutting material removed.

Drilling is an operation to create cylindrical holes by extracting the metal from solid material or by widening existing holes using multi-tooth cutting tools called drilling. There are various cutting tools available for drilling, but the most common is the twist drill.

The Egyptians drilled holes some 3000 years ago through bow drills in 1200 B.C. The bow drills are the mother of the current drilling machine for metal cutting. There are various types of drilling machine available in the market. 

Drilling characteristics:

• The chips must exit out from the hole created by the drilling process. 
• When chips are large or continuous, existing chips can cause problems. 
• At the entrance and for deep holes, the drill can wander. 
• Coolant may need to be delivered to the cutting front through the drill shaft for deep holes in large workpieces.
• The most likely drilling on the drill press is by someone who is not a machinist in the process of powder metal cutting.

There are several apparatus needed during the drilling operation. 

• Drilling machine
• Center punch 
• Hammer
• Center drill 
• Twist drill 
• Coolant
• Vernier calliper
• Two flute drill set 
• Center drill
• Countersink drill 
• Counterbore drill
• Drill various diameter

Types of drills:

Step drill to produce a hole of two or more different diameters. 

Core drill to enlarge existing holes.

Counterboring and countersinking to produce depression on the surface to accommodate heads of screws and bolts. 

Center drill a short and stubby drill to produce holes so that workpiece can be mounted between lathe centres. 

Spot drill to start a hole. 

Spade drill to remove large and deep holes. 

Crankshaft drill for good centring. Suitable for deep holes. 

Gun drilling for deep hole making, self-centring, lubrication, and coolant passage. 

Trepanning removal of disk-shaped piece.  

Twist drills to remove the metal in large volume in a minimum period of time. 

The formula for drilling operation:

The cutting speed of the drilling operation is the peripheral speed of the cutting edge. 

Cutting speed = π D N 

Where D =  drill diameter

N = Rotational speed in rpm 

A feed is the distance the drill penetrates per revolution ( mm / rev ). 

Each cutting edge is f / 2. 

Depth of cut is taken as half the diameter of drilling. 

Depth of cut = D / 2

Drilling time is the time taken to complete the drilling operation. 

 T = L / f * N

Where, f = feed-in mm / rev

N = rotational speed ( rpm )

L = the sum of hole depth 

Material removal rate ( MMR ) is the volume of material removed by the drill per unit time. 

MMR = ( π D² / 4 ) * f * N 

Explore more information: 

1. What is the size of the drilling machine?
2. How to use a drilling machine?
3. Safety while using a drilling machine
4. The function of the drilling machine
5. Care should be taken while using a drilling machine
6. Parts of drilling machine

What is electrochemical machining | Working principle | Application | Advantages and Disadvantages

Electro-chemical machining is one of the newest and most useful processes of metal removal by the controlled dissolution of the anode of an electrolyte cell.

The process is suited to metal and alloys which are difficult or impossible to the machine by mechanical processes.

This is based on Michael Faraday's classical laws of electrolysis, requiring basically the two-electrodes, electrolytes, a gap and a source of D.C power of sufficient capacity.

Working principle of electrochemical machining

In this machining process workpiece acts as anode and tool acts like cathode and the electrodes should be placed closely with a gap of about 0.5 mm. Anode and cathodes should be immersed in an electrolyte. A potential difference is maintained in between the electrodes as a result ions existing in the electrolytes and it migrates towards the electrodes. Positively charged ions are attracted toward the cathode and negatively charged ions are attracted towards the anode and thus the flow of current is initiated in the electrolyte. The setup is kept stationary and the tool is fed linearly the desired amount of metal is removed through the electrolysis process.

To keep the tool safe from damage by a continuous supply of electrolyte is ensured by pumping at high pressure. The temperature generated is very low and no spark produced this there may not any scope of metallurgical changes in the work material. The tool and the workpiece do not come in direct contact with each other so in this machining process negligible wear and tear are observed. By using this process dimensions up to 0.05 mm can be easily machined. 

Function of electrolyte 

The electrolytes used in this machining process are sodium chloride, sodium nitrate, potassium chloride, sodium hydroxide, sodium fluoride, sulfuric acid and sodium chlorate. 

The main function of electrolyte in this process is following below. 

• To carries the current between the tool and workpiece.
• Removes products of machining and other insoluble products from the cutting region.
• To dissipates heat produced in the operation.
• To keed the reaction continuous. 

What should be the criteria for selecting Electrolyte?

• Required Machining rate
• Required Dimensional Accuracy
• Surface Texture and Integrity

The essential characteristics of Electrolytes are following below. 

• Good electrical conductivity.
• Non-toxicity and chemical stability.
• Non-corrosive property.
• Low viscosity
• High specific heat.

The properties of Electrolytes are following below. 

• High Electrical Conductivity.
• High Current Efficiency for machining.
• Good Surface finish and integrity are necessary.
• Composition of the electrolyte and structure of the material controls the final surface texture. 

Tool material for electrochemical machining 

Copper, brass, titanium, copper-tungsten and stainless steels are most commonly used electrode material when the electrolyte is made of slats of sodium or potassium. Some material such as aluminium, graphite, bronze, platinum and tungsten carbide are also used for tool material.

Requirements of the tool material in electrochemical machining are following below.

• Tool material is a conductor of electricity.
• Because of the fluid pressure, it should be rigid enough to take up the load.
• The electrolyte should be chemically inert.
• Making it in the desired shape should be easy to machine.

Accuracy of electrochemical machining

Under ideal conditions with properly designed tooling, is capable of holding a tolerance of the order of (+0.02 to -0.02 mm) and less. Internal radius is greater than 0.2 mm and  0.05 mm an external radius. The taper is of the order of 0.010 mm for 10 mm depth and side over-cut is about 0.1 to 0.2 mm. Based on the work material, the surface finish of this process varies from 0.2 to 0.8 microns.

Factors which affect the accuracy are following below. 

• Machining Voltage.
• The feed rate of the electrode. 
• The temperature of the electrode.
• The concentration of electrolyte.

Application of electrochemical machining

The main application is machining of hard heat-resisting alloys. This process also used to make an aerospace component, machining of tungsten carbide and that of nozzles in alloy steels. Almost any conducting material can be machined by this method. The main process performed by the electrochemical machining process is electrochemical cutting, broaching, and drilling. 

Typically this method is used for mass production and works with extremely hard materials that are difficult to handle using other techniques but are limited to the use of electrically conductive materials.

Advantages of electrochemical machining 

• The metal removal rate is quite high for high-strength-temperature-resistant (HSTR) materials as compared to the conventional process.
• Accurate machining.
• Residual stress is low.
• Surface finish is in the order of 0.2 to 0.8 microns.
• No direct contact between tool and workpiece.
• Negligible wear and tear of tool material.
• Environmental friendly.
• Possible to machine non-rigid and open workpiece.
• It can be a machine configuration which is beyond the capability of the conventional machining process.
• Extremely thin sheets of metal can be worked easily without distortion.
• A job with complex shapes can be machined easily and accurately.
• Several holes can be done at once during drilling.
• It is a time-saving machining process as compared to conventional machining.
• Deburring can be done in hard to access areas.
• Fragile and brittle materials can be machined easily without cracking or breaking.
• The metallic workpiece is not damaged due to thermal stresses.

Disadvantages of Electrochemical Machining :

• Power consumption is more.
• Initial tooling can be timely and costly.
• Non-conducting materials can not be machined.
• The process is costly because of expensive equipment.
• Continuous supply of electrolyte is necessary.
• Steady voltage should be maintained during the whole process.
• Corrosion and rust of the machine can be a hazard.
• If hydrogen is liberated at the tool surface then it is possible to suffer from hydrogen-embitterment of the surface.
• There may be a possibility of damages because of sparks.
• Conventional machining produced more improved fatigue properties than electrochemical machining.

Read more related posts: 

1. Advantages and disadvantages of electrochemical machining