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Types of Machining Processes: Conventional vs Non-Conventional (Complete Guide 2026)
Created on 09.02
Machining is the core subtractive manufacturing process that turns raw metal bars, plates, castings, and blanks into precision functional parts. It is widely used in automotive, aerospace, medical, electronics, and industrial automation industries. For mechanical engineers, product designers, and global procurement teams, understanding different types of machining processes is critical for selecting the right manufacturing method, controlling tolerances, optimizing surface finish, and reducing production costs.
Not all machining methods deliver the same precision, speed, or material compatibility. Simple structural parts fit conventional machining, while ultra-hard materials, micro holes, and complex geometries require advanced non-conventional solutions.
In this full industrial guide from SMS Hardware, we systematically classify all mainstream machining operations, compare their working principles, advantages, limitations, and ideal applications, helping you quickly match the best process for your custom machined parts.
What Is Machining in Manufacturing?
Machining is a subtractive manufacturing technology that removes excess material from a solid workpiece using professional cutting tools, abrasive wheels, or energy-based processing methods. Unlike additive manufacturing, it achieves final shapes and tight tolerances by cutting away redundant stock materials.
It applies to standard stock materials such as flat bars, round bars, welded parts, and cast components. Common machined products include automotive parts, hardware fasteners, flanges, tooling components, robotic structural parts, and medical precision components. With strict process control, machining can achieve consistent dimensions, smooth surface quality, and high mechanical stability for industrial use.
Two Major Categories of Machining Processes
All industrial machining operations fall into two core categories: conventional (traditional) machining and non-conventional (advanced) machining. The biggest difference lies in the material removal mechanism: conventional machining relies on direct mechanical contact, while non-conventional machining uses electricity, chemistry, laser, ultrasonic, and other energy forms for non-contact processing.
Conventional Machining: Traditional Contact Machining Processes
Conventional machining refers to classic mechanical cutting methods with direct tool-workpiece contact. It features high material removal efficiency, low comprehensive cost, mature technology, and wide compatibility with common metals and plastics. It is the primary process for prototyping, small-batch customization, and mass production of standard mechanical parts.
1. Turning
Turning is a lathe-based machining process where the workpiece rotates at high speed while the cutting tool remains stationary and moves along linear axes to remove excess material. It is the most suitable process for axisymmetric parts such as shafts, bolts, sleeves, and cylindrical pins.
Turning covers both exterior and interior processing: exterior surface finishing is called facing, while inner hole processing is defined as boring. SMS Hardware adopts high-precision CNC turning to ensure uniform diameter tolerance and smooth outer surface for rotary parts, suitable for mechanical transmission and automation equipment components.
2. Milling
Milling uses high-speed rotating multi-edge cutters to strip material from workpieces, ideal for flat surfaces, grooves, irregular contours, and complex 2D/3D structures. It is divided into face milling for surface flattening and slab milling for wide planar cutting via cutter peripheral edges.
As one of the most versatile machining methods, CNC milling supports complex structural parts with tolerances up to 0.02mm. SMS Hardware’s 3/4/5-axis milling capability meets high-precision requirements for automation fixtures, robotic brackets, and electronic equipment shells.
3. Drilling
Drilling uses multi-point spiral drill bits to create standard cylindrical holes in solid workpieces. The spiral flutes on drill bits timely discharge metal chips to ensure smooth hole forming. It is the basic pre-process for tapping, reaming, and boring operations, widely used for part assembly and connection structures.
Precision drilling guarantees verticality and consistent hole diameter, laying a foundation for subsequent thread processing and assembly matching. It is indispensable for hardware structural parts, automotive components, and industrial equipment assembly parts.
4. Grinding
Grinding is a precision finishing process that uses abrasive wheels to remove tiny workpiece materials, effectively optimizing surface smoothness and tightening dimensional tolerances. It is the core process for post-finishing of high-precision parts and supports follow-up honing, lapping, and superfinishing treatments.
Common types include surface grinding for flat workpiece finishing and cylindrical grinding for circular shaft and sleeve parts. Grinding ensures uniform size, consistent finish, and high flatness of mass-produced precision parts.
5. Sawing
Sawing is mainly used for blanking and fixed-length cutting of profile materials such as metal bars, tubes, and plates. Equipment includes circular saws, hack saws, and abrasive wheel saws. Different materials require matched cutting speeds: soft aluminum alloys adapt to high-speed cutting above 1000 fpm, while high-temperature alloys need low-speed cutting below 30 fpm to avoid tool wear and material cracking.
6. Broaching
Broaching uses multi-tooth hierarchical broach tools to complete one-time forming of special-shaped holes, keyways, and spline structures. Unlike files with uniform teeth, broach tools have incrementally sized teeth to realize progressive depth cutting.
Divided into push broaching and pull broaching, this process features high forming accuracy and high efficiency. Soft metals adopt a cutting speed up to 50 fpm, while high-strength metals require a low speed of 5 fpm, suitable for standardized special-shaped hole batch processing.
7. Planing
Planing is suitable for large flat workpiece finishing and pre-processing before scraping treatment. To improve production efficiency, multiple small workpieces can be clamped together for simultaneous planing. It is widely used for flat processing of large mechanical structural parts and thick plate components.
Non-Conventional Machining: Advanced Non-Contact Machining Processes
Non-conventional machining, also known as modern precision machining, abandons traditional mechanical cutting. It uses electrical energy, chemical energy, laser energy, ultrasonic vibration, and other physical/chemical methods to remove materials. It solves the processing pain points of ultra-hard, brittle, heat-sensitive materials and ultra-complex micro structures that conventional machining cannot handle.
1. Electrical Discharge Machining (EDM)
Also called spark machining or wire erosion, EDM uses high-frequency spark discharge erosion between electrodes and workpieces to remove materials. It requires no mechanical contact, produces no cutting force, and avoids workpiece deformation.
EDM excels at processing ultra-hard alloys, exotic materials, and high-precision mold parts. Although its material removal speed is relatively slow, the processed parts have extremely high precision and smooth surfaces, requiring almost no secondary polishing.
2. Chemical Machining
Chemical machining immerses workpieces in matched etching solutions to uniformly dissolve surface materials. The complete system includes anti-corrosion processing tanks, constant-temperature heating coils, stirring devices, and special jigs.
This process is suitable for hard and brittle difficult-to-machine materials, with low tooling cost and no burrs on finished surfaces. It features fast material removal and is ideal for batch fine processing of thin-wall parts and special-shaped components.
3. Electrochemical Machining (ECM)
ECM, known as reverse electroplating, removes materials through electrode current and conductive liquid reaction without spark generation, tool wear, or thermal stress. It can form mirror-level surface finishes and maintain efficient material removal.
With high initial equipment investment, ECM is more suitable for mass production. It perfectly processes ultra-hard alloys, deep small holes, and irregular complex structures, widely used in aerospace and high-end precision equipment manufacturing.
4. Abrasive Jet Machining
This process uses compressed gas to spray high-speed abrasive particle streams to impact workpiece surfaces and strip tiny redundant materials. The complete equipment includes air supply systems, filters, pressure regulators, mixing chambers, and hard-alloy nozzles (0.18–0.8mm diameter).
Abrasive jet machining can process dead-angle structures inaccessible to traditional tools, with low processing heat and minimal workpiece deformation. It is commonly used for mold parting line removal, part engraving, metal foil cutting, and plastic deburring.
5. Ultrasonic Machining
Ultrasonic machining relies on high-frequency low-amplitude vibration, cooperating with water-based abrasive slurry (100–1000 grain size) to impact and remove workpiece materials. It produces low heat and smooth surfaces, ideal for high-hardness brittle materials such as ceramics, glass, and hard alloys.
Its flexible vibration processing mode easily realizes special-shaped hole forming and micro-finishing of fragile precision parts.
6. Electron Beam Machining (EBM)
EBM focuses high-energy electron beams on local workpiece areas to realize precision material removal. It has no geometric processing restrictions, low tooling cost, and can process ultra-small high-precision holes on hard and brittle materials, belonging to high-end micro-precision machining technology.
7. Laser Beam Machining (LBM)
Laser machining uses high-energy laser thermal energy for non-contact cutting, drilling, and engraving. It features fast cutting speed, automatable complex pattern processing, and zero tool wear. It is suitable for micro-hole machining, thin-plate cutting, partial engraving, and precision trimming of various hard materials.
Conventional vs Non-Conventional Machining: Core Comparison
Choosing the correct machining process directly affects part precision, surface quality, production cycle, and overall cost. Below are the key differences to help engineers quickly select the optimal solution:
- Material Removal Principle
: Conventional machining uses physical tool cutting; non-conventional machining uses energy-based non-contact material removal.
- Material Adaptability
: Conventional methods suit common metals and plastics; non-conventional methods adapt to ultra-hard, brittle, heat-sensitive, and special composite materials.
- Precision & Surface Finish
: Non-conventional machining delivers higher consistency, finer surface finish, and tighter micro-tolerances with no tool deflection.
- Processing Speed & Cost
: Conventional machining has high material removal efficiency and low cost for mass production; non-conventional machining has slower speed and higher setup cost but solves complex processing pain points.
- Tool Wear & Deformation
: Conventional machining has obvious tool wear and mechanical cutting force risk of thin-part deformation; non-conventional machining has almost no tool wear and zero cutting force deformation.
How to Choose the Right Machining Process for Your Parts
For most industrial custom parts, conventional turning, milling, drilling, and grinding are the most cost-effective solutions for standard structures, moderate precision, and mass production. For special scenarios, non-conventional processes are irreplaceable:
- Ultra-hard alloy, ceramic, and brittle material parts → EDM / Laser / Ultrasonic Machining
- Micro holes, invisible dead angles, and ultra-complex structures → ECM / Abrasive Jet Machining
- High mirror surface and zero-stress precision parts → Electrochemical Machining
- Large-batch standard structural parts → Turning & Milling conventional composite processing
Why Choose SMS Hardware for Custom Machining Services
SMS Hardware provides full-type machining solutions covering both conventional and non-conventional processes, supporting one-stop customized manufacturing from prototype verification to mass production for global industrial clients.
- Full-process coverage: CNC turning, milling, drilling, grinding, sawing, broaching, and advanced EDM, laser, ultrasonic precision processing
- Wide material compatibility: Aluminum, steel, stainless steel, brass, copper, engineering plastics, and special hard alloys
- Strict precision control: Stable tolerance control, consistent batch surface finish, compliant with industrial assembly standards
- Professional engineering support: Free DFM analysis, process optimization suggestions, and fast customized quotation
- Flexible production mode: Adapt to small-batch prototype trial production and large-batch standardized orders
Final Thoughts
Conventional and non-conventional machining processes complement each other in modern manufacturing. Traditional contact machining undertakes most standard and mass-production tasks with high efficiency and low cost, while advanced non-conventional machining breaks through the limitations of materials and structures, supporting high-end precision industrial manufacturing.
Whether you need simple structural hardware parts or ultra-precision micro complex components, SMS Hardware can match the most scientific and cost-effective machining process according to your drawings and usage scenarios.Send us your design files now to get a professional custom machining solution and accurate quotation.
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