Types of Machining Processes

Maybe you have been wondering what machining processes are available and which of them will fit your operations. Your questions are answered in this article because we give details on the available machining processes.

Examples of Machining Operations

1. Turning

Turning requires the use of a rotating cutting tool that can bring a meaningful function to cylindrical-ended workpieces.

Working Process:

When operating a turning machine, the first step is to prepare your workpiece by securing it in place using a workpiece holder. Choose a cutting tool that is suitable, set all the parameters required for this particular workpiece and start the machine.

As the workpiece rotates along a central axis, create contact between the workpiece and the cutting tool. At this point, the tool removes unwanted material from the workpiece. You can disengage the cutting tool from the workpiece when it’s ready.

Machines & Tools used for Turning Machining

• Lathe Machine
• Chip conveyer
• Cutting tool
• Coolant
• Work holding tools

Applications of Turning Machining

Turning is appropriate for industries that deal in making shafts, taper, threads, holes, machine parts, engine parts and grooves.

2. Milling

Milling is the process of employing a multi-tooth cutter hanging on a rotating axis to chop off unwanted material from a given workpiece. The unwanted material is chopped off in the form of chips creating the desired functional part.

Milling Processes:

When it comes to milling, the basic idea is to take the material from the workpiece using rotary cutters. You can position it in any of the directions; vertical, horizontal, angular for creating different designs with distinct shapes and features. As the tool rotates, it comes into contact with the workpiece and chop off material creating the needed shape.

Machine and Equipment:

• Milling machines
• Power system
• Monitoring and control system
• Chip conveyer
• Coolant
• Toolholders
• Cutting tool

Applications of Milling

Milling operations are necessary for applications that require slotting, thread making, gear cutting, contouring, etc.

3. Drilling

Drilling process employs the services of a rotating tool called a drill bit to design holes in various workpieces. A drill bit is kept in tension between the tube and the workpiece for a round hole outcome.

Working Process of Drill Machining

To drill, you will need to set up your workpiece, select your drill bit, drilling machine, set parameters and start off. By turning on the drilling system, you are ready to create contact between the drill bit your piece. Bit by bit the cutting tool can now eliminate the unwanted material from the main piece, leaving a functional bit.

Machines & Tools used for Drilling

• Drilling machine or drill presses
• Chip conveyers
• Drill bit
• Tool holders
• Work holding devices
• Coolant

Applications of Drilling

Drilling is a necessary machining step that creates cylindrical holes used for further finishing procedures or for assembly. Drilling can also be used for aesthetic purposes and making screw holes, threads.

4. Grinding

Grinding is a high-precision operation generally performed using abrasives bound to a disc called a wheel. It is used to get height precision, finished hard surfaces, and better performance due to surface quality of materials after being hardened.

Grinding Processes

Grinding involves a rotating grinding machine or a disc in the form of a wheel that removes material from given workpieces. The rotating wheel is packed with corrosive particles that when it touches the surface of the workpiece it grinds into it. This process creates a smoother surface on the workpiece.

Machines & Tools used for Grinding

• Grinding machine
• Wheel balancing system
• Power source
• Monitoring and control system
• Grinding wheels
• Dressing tools
• Work holding tools
• Coolant tools

Applications of Grinding

Grinding ensures a smooth and appealing surface finish for your parts. It can also be used for sharpening blades and honing different tools.

5. Planing

Planning employs the use of a planer tool or machine to linearly cut through a large workpiece or smaller workpieces put together.

Working Process of a Planer Machine

With the workpiece and the cutting too in place, the machine is started. The cutting tool moves linearly along the workpiece to remove the unwanted material bit by bit. Since the process produces a lot of heat, a coolant is applied to the workpiece.

Machines used in Planing

• Planer machine
• Monitoring and control system
• Power source
• Coolant
• Tool holders
• Cutting tools

Applications of Planing

Planing is not capable of producing accurate results and is mostly used surface preparation purposes. In some cases, planing is used for manufacturing larger workpieces that cannot be handle by other machining processes.

6. Broaching

The term “broaching ” is a machining process that takes away material by a special tool called broach. Broaches use teeth where the size of each is kind of increasing from the first towards the last teeth. Their function is to cut hard shapes, such as keyways and splines, in a single pass.

Broaching Process

A broach, which is a machine designed with various teeth, is driven into a given workpiece to create a desired pattern. The teeth have a sequential arrangement making sure that the next tooth is larger than the previous one. The resulting product is perfect and may not need additional finishing processes.

Machines & Tools used for Broaching

• Broaching machine
• Monitoring and control machine
• Cooling system
• Tool holders
• Work holding tools

Applications of Broaching

Broaching is used to create keyways, square holes, spline holes, gears, slots, etc.

7. Boring

Boring can be described as a secondary process that ensures that the pieces that were previously machined become fully functional. A boring head is used to achieve accurate and precisely refined holes.

Boring Process

A boring head or a single-point cutter offering multiple cutting edges is placed into an already drilled hole. The boring head progresses symmetrically into the given hole to modify and refine the internal finishes.

Machines used for Boring

• Boring machines
• Power source
• Boring heads
• Work holding tools

Applications for Boring Operations

Boring operations are necessary for tool and die making, gearbox manufacturing, machine tool spindles, aerospace components, engine cylinder, etc.

8. Reaming

With a reamer machine, your work will be to ensure that previously drilled become more precise and of quality for applications. It makes the drilled or bored hole round, smoother and more accurate.

Reaming Processes

A rotating reamer machine, moving at a set speed, is slowly and gradually driven into the drilled hole through a feed mechanism. As the reamer moves into the hole, its multiple edges get rid of material from the given hole in a workpiece. The end product is smoother with more accurate dimensions.

Machines and Tools for Reaming Operations

• Reaming machine
• Power source
• Reamer tool
• Tool holders
• Measuring instruments

Applications of Reaming

Reaming operations are applicable in industries that make landing gear, fuselage, aircraft components, and engine parts.

9. Tapping

Tapping is a machining process that aids in creation of threads within holes or any other openings to enable installation of fasteners. A fastener could be in the form of a screw or a bolt.

Tapping Process

For tapping to occur, you need a tap in the form of a bolt packed with flutes. The tap has to be rotating within the hole to create threads that will fit a given screw/bolt and components. Tapping gives the hole or opening a meaningful function.

Machines used for Tapping

• Tapping machines
• Power source
• Coolant system
• Tool holder
• Work holding tools
• Taps

Applications for Tapping Operations

All industries that deal in bolted and threaded components, like automobiles and machines among others, require the services of a tap.

10. Sawing

Sawing operations can also be explained as the process of reshaping various workpieces by eliminating extra materials through cut-off machines. Some of the cut-off machines commonly used are circular saws, power hack saws and wheel saws.

Sawing Processes

A cut-off machine connected to a saw is involved in cutting workpieces into smaller pieces. The process may not be as accurate as other precision machining procedures.

Machines & Tools for Sawing

• Sawing machine (table saw, bandsaw, jigsaw or circular saw).
• Power source
• Control and monitoring system
• Tool holder
• Safter tools
• Measuring tool
• Coolant
• Saw blades

Applications of Sawing

Sawing is mostly applicable when there is need to reduce the sizes of given workpieces to manageable sizes. This is an important step because subsequent machining operations will run smoothly. Another application involves production of thinner sections of a given workpiece.

11. Knurling

Knurling is a machining process that employs the use of a knurling pin to create different patterns on various workpieces. Other reasons for knurling would be for general aesthetic purposes.

Knurling Processes

The knurling pin is rolled onto the surface of the workpiece to produce the intended patterns through the aid of abrasives. These abrasives are attached to the knurling to cause abrasion on the working.

Machines and Tools used in knurling

• Knurling machine
• Control system
• Knurling tools
• Work holding tools

Applications of Knurling

Knurling is recommended for industries that deal in making tools that are hand-gripped tools, aesthetic appeal workpieces and more.

12. Electrical Discharge Machining (EDM)

Electrical Discharge Machining utilizes charges that are capable of sending electric impulses to the given workpiece to eliminate extra material. It is a predominant option for making intricate patterns (broaches, jewelry, etc.) in high-strength materials (steel, aluminum, etc.).

Working Process of EDM

In electric discharge machining, spark transmitted via a given dielectric fluid from a charged electrode hits the conductive workpiece. On hitting the workpiece, the unwanted material is removed according to the predetermined parameters. This means that EDM can only work with conductive metals to obtain highly fine and intricate features.

Machines used in EDM

• EDM machines
• Power source
• Control system
• Coolant
• Electrodes
• Dielectric fluid

Applications of EDM

EDM is useful for making accurate and precise intricate parts as produced in industries like automotive, aerospace and medical.

13. Electro Chemical Machining (ECM)

Electrochemical machining (ECM) is also called reverse electroplating. This is a process that uses a conductive liquid and electrodes to discharge its machining operations. Unlike electrical discharge machining, it neither makes sparks nor transmit thermal stress.

Working Process of Electrochemical Machining

Once the machine has been set up and the workpiece is put in place, current is applied to the workpiece through the electrolyte. Through the principles of electrolysis, material is removed from the workpiece depending on the set parameters. For this process to happen, you need a cathode, electrolyte, power source, workpiece and a container.

Machines used in Electro-chemical Machining

• Electro-chemical machining machine
• Control and monitoring system
• Cooling and filtration tools
• Electrolyte solution

Uses of Electro-chemical Machining

Electrochemical machining is used for drilling holes, profiling, making turbine blades, contouring, die sinking etc. this method is mostly used in industries like automotive, electricals, aerospace, etc.

14. Ultrasonic Machining

Ultrasonic machining is a special machining processes that makes use of a high-frequency ultrasonic tool to move abrasives to shaping workpieces.

Working Process of Ultrasonic Machining

After setting the ultrasonic transducer or sonotrode, you also need to set the workpiece in its holder. This is followed by the introduction of a high-frequency vibration achieved through an ultrasonic vibrator. These vibrations are transferred to the advanced leading to a high impact between the workpiece and the abrasives.

A continuous impact on the workpiece surface uniformly removes material that is unwanted. When material removal is over, the next stage is cooling and lubrication.

Machines and Tools used in Ultrasonic Machining

• Control and monitoring systems
• Ultrasonic generator
• Ultrasonic transducer
• Workpiece fixture
• Abrasive slurry
• Coolant and Lubrication tools

Applications of Ultrasonic Machining

Ultrasonic machining is suitable for tasks like sinking, profiling and micro-drilling in industries that deal in glasses and ceramics.

15. Chemical Machining

Chemical machining is a simple subtractive method gets rid of material from a given part using a bath containing corrosive chemicals. The etchant will uniformly remove the unwanted material from the workpiece.

Working Process of Chemical Machining

This machining process requires an etchant or corrosive chemical that can corrode and remove material from a workpiece. The first step is to create a mask on sections that don’t need etching. Contact between the workpiece and the heated etchant leads to corrosion and finally material removal. After material removal you can use water or other solvents to clean the part.

Machines used for Chemical Machining

• Control and monitoring system
• Temperature control
• Masking equipment
• Agitator – used for stirring the mixture
• Etching Tank
• Etchant solution
• Rinsing and drying tools

Applications of Chemical Machining

Chemical machining is known for precision is used for machining workpieces in industries like aerospace, electronics.

16. Abrasive Jet Machining

Abrasive jet machining allows that use of a mixture of a properly chosen abrasive and air or a particular gas. The mixture is released at high speed on a workpiece via tiny nozzle. Abrasion or corrosion becomes the main cause of bit-by-bit material removal from a particular workpiece.

How Abrasive Jet Machining Works

At the mixing chamber, gas is released at a high speed to mix with the abrasive powder through vibrations. The mixture has to go through a connecting hose in order to be released via the thin nozzle. Through the tiny nozzle, this mixture hits the workpiece repeatedly at an elevated velocity getting rid of the unwanted sections.

Machines & Tools used in Abrasive Jet Machining

• Abrasive recycler
• Monitoring/Control system
• Abrasive delivery machine
• Safety equipment
• Workpiece holder

Applications of Abrasive Jet Machining

Most manufacturers use abrasive jet machining operations for activities like polishing glass, super-alloys, complex shapes, slots, etc.

17. Electronic Beam Machining (EBM)

Electronic beam machining makes use of a focused electronic beam in turning various unfinished workpieces into perfectly functional pieces. An EBM is basically applicable to conductive materials as it uses heat to carry out its processes.

How Electronic Beam Machining Works

Working with an electron beam to carry out various machining operations requires a vacuum environment. Within the vacuum, the electrons are produced and are directed to the surface of a workpiece at a high velocity. Immediately the workpiece senses an impact of the electrons, its heated up and melted and eventually vaporized.

Machines and Tools for Electronic Beam Machining

• An electron gun
• Beam deflection system
• CNC system
• Vacuum chamber
• Magnetic lenses
• Workpiece holder
• Safety equipment

Applications of Electronic Beam Machining

You use it in making tiny holes in workpieces and also in micro-finishing procedures in industries like Aerospace, medical, microelectronics, etc.

18. Laser Beam Machining (LBM)

The laser cutting is one of the thermal cutting operations which utilizes a high-power laser beam to burn through different materials. The process is non-contact procedure but create heat.

How Laser Beam Cutting Works

Laser beam is produced by inducing stimulated emission process through a medium with population inversion. This is followed by manipulation of the light beam using optical resonator resulting in a beam of light with desired characteristics. Focusing the laser beam onto a given workpiece surface results into melting, vaporization or just ablation to remove the unwanted materials.

Machines and Tools used in Laser Beam Cutting

• The laser beam machine
• Computer Numerical Control system
• Gas supply machine
• Safety equipment
• Workpiece handling tools
• Cooling tools

Applications of Laser Beam Machining

Laser beam machining results into precise parts and is suitable for applications like surgical procedures, tiny hole fabrication, macro hole machining.

19. Water Jet Machining

Waterjet cutting is a very multipurpose and precise manufacturing technique which is accomplished by the employment of a highly pressurized water.

Water Jet Machining Process

Waterjet machining equipment usually depends on pumps that pressurize the water to extremely high pressures. This particular water flow is then sent through a smaller dome-shaped hole which gives it a targeted flow. The jet is capable of shaping and cutting different parts to give them functionality.

Machines used in Waterjet Machining Process

Some of the machines needed in waterjet machining include CAD software and waterjet cutting machine.

Tools and Equipment used in Waterjet Machining Process

Tools that are necessary for a waterjet machining process include abrasive feeder, cutting table, material handling tools.

Applications of Waterjet Machining

Waterjet machining can be useful for making composite materials, foam packaging inserts, gaskets, metals components, signage and artwork, medical devices.

20. Ion Beam Machining

In ion beam machining, workpieces are shaped or machined into precision and perfection through the use of a focused beam of ions.

Working Process of Ion Beam Machining

An electron gun is used to discharge free electrons at the start of the whole process. These electrons are released into an argon gas chamber which leads to ionizing. Through the ion beam generating apparatus, a beam of ions is focused on the workpiece put in place.

When the ion beam hits the surface of the workpiece it removes the unwanted material leaving it smooth and attractive.

Machines used in Ion Beam Machining

• Ion beam machines
• Ion source
• Beam deflection system
• Control and monitoring system
• Workpiece holder
• Vacuum system
• Safety tools

Applications of Ion Beam Machining

Ion beam is useful in micro-machining most electronic parts such as computer components. The process is also recommended for figuring optical surfaces and also making fine wire dies.

21. Micro Machining

Micro-machining means creation of workpieces with minute and intricate features that may not be possible to achieve through other machining methods. This process can be achieved through any of the discussed machining methods; however, it has to be micro.

Working Process of Micromachining

Micromachining bases its operations on minute material removal from the surface of a given workpiece. The process may involve thermal, chemical or mechanical operations. As long as it can eliminate material from a workpiece and come up with the necessary features and geometries, it is good.

Machines like EDM systems or high-precision CNC milling can handle the micromachining operations.

Machines used in Micromachining

• Micromachines (micro laser, micro miller, micro EDM, etc.)
• Power source
• Control and monitoring system
• Micro cutting tools
• Holder tools

Applications of Micromachining

Various industries including medical and electronics require the magic offered by micromachining to produce precise and intricate parts.

22. Precision Machining

Precision machining involves using modern technologies to modify and cut material sections. In most cases, these machining operations are computer controlled to achieve very tight tolerances.

This process involves the use of computer-controlled machines to achieve the required precision.

Working Process of Precision Machining

In precision machining you must use fine cutting designed with highly sharpened edges that can accurately eliminate non-useful material from workpieces. The workpiece is held in place by holders as the cutting tool gets into contact to precisely create precisely fitting parts.

Machines used in Precision Machining

• Drill press
• Power source
• Milling machine
• Lathe machine
• Radial arm drill
• Shear
• Workpiece holders
• Coolant

Applications of Precision Machining

Generally, most applications require precisely machined parts for optimum performance. Among industries that require accurate and precise parts include aerospace.

Comparing Conventional Machining Vs. Non-conventional Machining

Generally, manufacturers have two main categories of machining to choose from; the conventional and non-conventional machining. Here, material is removed to make sites suitable for desired shapes and features. Here’s a comparison between the two:

Conventional Machining: The traditional machining ways involving mechanical operations (removing stock using the cutting, grinding, and milling), which in time produces the product.

Non-conventional Machining: Non-conventional machining, is a range of modern machining technologies that do not strictly use mechanical impacts.

Mechanism of Material Elimination

Conventional Machining: In classical milling, actual material detachment occurs predominantly due to mechanical cutting. In addition, milling, turning, or drilling for example use cutting tools in order to remove material by shear deformation.

Non-conventional Machining: Non-conventional machining processes are a set of methods that replace the conventional kinds. They utilize either laser, plasma, or electrochemical actions to remove material.

Material Suitability

Conventional Machining: The machining processes which are standard are usually a great option when it comes to materials like metals, plastics and composites.

Non-conventional Machining: And of critical importance are the non-traditional processes are best for machining hardened materials like metals or non-metallic materials like ceramics and polymers.

Tolerance and Surface Finish

Conventional Machining: The machines that follow conventional machining have limited precision when it comes to tolerances.

Non-conventional Machining: On the other hand, non-conventional machining processes are capable of attaining high precision and accuracy. The operation requires the right choice of tools and machines.

Complexity of Geometry

Conventional Machining: In the world of manufacturing, there are many options for machining simple to moderately complex geometries. But there are conventional machining processes for all of these works. Yet, machining shapes that are more complex or difficult could require the non-conventional methods.

Non-conventional Machining: These alternative machine processes are more effective at machining complex and intricate shapes that come with internal features and minute details. In this case, they are more flexible and provide with the option of creating parts with unexpected shapes and complex features.

Tool Wear and Maintenance

Conventional Machining: In the case of conventional machining, cutting tools wear out easily and hence repetitive sharpening or replacement might be involved.

Non-conventional Machining: Unconventional machining processes tend to create less tool wear, which is usually a thing among traditional machining.

Heat Generation and Material Distortion

Conventional Machining: Machining procedures as they were known traditionally produce thermal deformation of the workpiece when cutting as well as residual stresses. This is more prominent with tough-to-machine materials.

Non-conventional Machining: These non-standard machining techniques usually produce less affected zones and less thermal changes. This is because the material removal takes place in the form of abrasion, melting and sublimation, not mechanical cutting.

FAQs

What is Machining?

Machining is basically the procedure or process through which fine, accurate, precise and functional parts are created by extra material elimination. This process utilizes lasers, CNC (Computer Numerical Controlled) production machines, as well as other tools with specific list types of algorithms.

What is CNC Machining Process?

CNC machining is to say that the material elimination from parts or workpieces has to be monitored and controlled. And this is achieved through a computer connected to the system. It provides an opportunity of making the assembly lines highly automated and more precise.

Conclusion

In summary, all the above machining processes are capable of performing the various machining operations independently. However, your choice can be determined by factors like speed, costs, precision, etc. You use the information above to choose which the process that will serve you best.

More resources:

Turning Center vs Lathe – Source: TSINFA

Lathe Machines – Source: TSINFA

CNC Machine Tooling – Source: TSINFA

Tuning in Machining – Source: XOMETRY

Surface Grinding Machines – Source: TSINFA

Thread Milling vsTapping – Source: TSINFA

EDM Explained – Source: TSINFA