Machining is key to manufacturing. It includes many techniques for cutting and shaping materials. They make accurate parts and assemblies. These operations are split into two categories. The categories are traditional and non-traditional. Traditional methods include turning, drilling, and milling. Non-traditional methods include EDM, laser cutting, and chemical machining.
The importance of machining operations in modern manufacturing cannot be overstated. It supports many industries, from aerospace to consumer goods. It’s also key to making precise, quality products. In the following article, Yonglihao Machinery will take you through the classification and differences of machining operations. It will do so in detail. To help you choose the right machining method.
Table of Contents
What is Machining?
Machining is a material reduction manufacturing process. The process typically uses cutting tools, discs, grinding wheels, etc. to remove excess material from a workpiece. In addition, the process can be used to remove unwanted material to create the desired product shape. Machined objects typically include plates, bars, weldments, or castings.
Examples of machined products include automotive parts, drills, plaques, nuts and bolts, flanges, and other parts and tools used in different industries. Next, let’s take a look at the various machining processes.
Types of Machining
Traditional machining processes and non-traditional machining processes are the two types of machining. In addition to these two main types, there are other sub-types that can help achieve the end product you want. Let’s take a closer look at these machining processes.
Traditional Machining Processes
Conventional machining is a manufacturing method that uses a cutting tool to make direct contact with a workpiece to remove excess material. This machining process occurs when the cutting tool is in close contact with the workpiece. Conventional machining processes include the following types:
Turning
During turning, the cutting tool does not move but the workpiece rotates. This is a lathe process that uses the cutting tool to remove excess material from the workpiece. In addition, the cutting tool moves in both axes to cut with precise width and depth.
On the other hand, the turning process is ideally suited for machining the interior or exterior of a material. Turning performed on the outside of an object is known as face turning and turning performed on the inside is known as boring turning.
Milling
Milling is a process that uses a rotating tool to remove material from the workpiece being machined. There are two main types of milling: face milling and slab milling.
Face milling is a machining manufacturing process used to smooth or level the surface of a workpiece. On the other hand, slab milling is best suited for cutting wide, flat surfaces.
Moreover, this type of machining includes a complex process. Therefore, different special tools are usually required to get the job done. However, machining companies like Yonglihao Machinery can offer 3-axis and 5-axis CNC milling services, milling parts to tolerances of up to 0.02 millimeters.
Drilling
Drilling involves the use of drills (multi-point cutting tools) to drill cylindrical holes in solid materials. In addition, the drill used for this process has two helical passages. These passes help in removing debris or swarf from the hole as the drill bit continues to drill into the material.
In addition, the holes drilled by this type of drilling machine usually help in putting the parts together. Drilling is done first before tapping, reaming, or boring to make threaded holes or to ensure that the holes are of the correct size. Therefore, drilling is one of the most important of the different machining processes.
Grinding
Grinding is one of the most suitable machining processes for improving the surface finish of parts and improving tolerances. In addition, this process provides consistency in the shape, finish, and dimensions of the part. It is the first step before other finishing operations such as grinding and superfinishing.
The two main types of grinding machines are surface grinders and cylindrical grinders. Surface grinders grind off small amounts of material from a flat surface. In contrast, cylindrical grinders remove material from a cylindrical shape.
Sawing
Sawing is the use of cutting tools to cut longer materials (such as extruded shapes or bars) into shorter lengths. Engineers use a variety of cutting tools for sawing. Examples include power hacksaws, circular saws, and abrasive wheel saws.
In addition, the cutting speed of sawing depends on the material being cut. For example, softer materials, such as aluminum alloys, require a cutting speed of 1000 fpm or more. On the other hand, some hot metals require slower cutting speeds of 30 fpm.
Broaching
Broaching is the process of machining square holes, splined holes, keyways, and other shapes using a tool called a broach. A broach is a tool with many teeth arranged in sequence like a file. It is important to note that the teeth of a broach are uneven, whereas the teeth of a file are all the same size.
In addition, a broach makes multiple cuts with increasing depths of the cut as it pulls or pushes across a surface or through a pilot hole. The cutting speed of a broach depends on the strength of the material. For example, for softer metals, cutting speeds of up to 50 fpm are possible, while for stronger metals, cutting speeds drop to 5 fpm.
Non-Traditional Machining Processes
This precision machining process removes material from the workpiece without touching it. In other words, the tools in non-traditional machining processes do not need to be in direct contact with the cutting material. The following are a few common non-traditional machining processes:
Electrical Discharge Machining (EDM)
The Electrical Discharge Machining (EDM) process is also known as spark machining, die engraving, wire cutting, or wire ablation. This process removes material by eroding it. In addition, this machining method does not require tools to touch the object being machined. This makes it ideal for processing fragile materials that are easily damaged.
In addition, EDM is well suited for cutting specialty materials that are extremely hard and have very tight tolerances. Although EDM removes material slowly. However, parts machined with it usually require little or no finishing.
Chemical Processing
Chemical machining is the process of placing an item into a bath containing an etching solution. The etching solution used in this process is usually a mixture of strong acids that react with the metal. When the metal is immersed in the etching solution, it dissolves uniformly. Additionally, for the chemical process to run smoothly, you will need tanks, hot coils, agitators, and workpieces.
In addition, this process is ideal for working with hard, brittle, and other difficult materials. This process has low tooling costs and produces smooth, burr-free parts. In addition, machining with this process saves time due to the high material removal rate.
Electrochemical Machining (ECM)
Electrochemical machining (ECM) is also known as reverse plating. Unlike normal plating, this process removes material from the workpiece rather than adding material. In addition, it is similar to EDM because it passes a strong electric current between an electrode and a conductive liquid. The difference is that it does not produce sparks and does not wear out tools. In addition, it does not generate thermal diffusion or mechanical stress. On the other hand, ECM produces a smooth mirror surface and removes large amounts of material quickly.
On the other hand, ECM has a high initial setup cost. However, this process is best suited for mass production. Moreover, it is a versatile machining process. Ideal for cutting very hard metals and alloys, it is also suitable for machining special shapes, small parts, and deep holes.
Abrasive Jet Machining
This non-traditional machining process uses tiny abrasives moving at high speeds to impact the workpiece. When these coarse particles hit the workpiece frequently, propelled by gas or air, they loosen small pieces of material. The jetter then removes the free debris from the workpiece, exposing a new surface on which the abrasive particles can impact.
A major advantage of this processing method over other methods is its flexibility. The hose used in this process can move the abrasive material to any part of the workpiece to be machined. This includes areas that are typically difficult to reach with other cutting methods.
Additionally, abrasive jet processing generates very little heat. This helps prevent products and parts from warping during the manufacturing process. On the other hand, it is an excellent tool for removing seams from injection-molded parts and making lasting engravings in materials. In addition, it is very effective in cutting metal foils, machining strong metals, and smoothing plastic burrs.
Ultrasonic Processing
Ultrasonic machining uses low amplitude and high-frequency vibrations to cut materials from surfaces. In addition, the process takes place with fine abrasive particles mixed with water to form a slurry. The particle size varies, usually between 100 and 1000.
In addition, ultrasonic processing uses smaller grain sizes and less heat to create a smooth surface. This process is best suited for hard or brittle materials. In addition, its vibratory motion easily cuts out hole patterns.
Laser Beam Machining (LBM)
Laser Beam Machining (LBM) is a method of removing material from a workpiece using laser and thermal energy. LBM is well suited for drilling and cutting tasks. It can machine very small holes or cut complex shapes in hard materials.
In addition, the LBM is effective for partial cutting or engraving, trimming steel, adjusting resistors, and blanking. On the other hand, the LBM is fast and can cut shallow angles. It makes the automation of complex cutting patterns easy. Since LBM is a non-contact process, there is no tool wear or breakage during the process.
Detailed Classification of Machining Operations
Turning: Types, Materials, and Applications
Turning is one of the most common machining methods. It removes material by rotating the workpiece and using cutting tools to shape and size it. Turning operations can be divided into types like longitudinal turning, transverse turning, grooving, and thread turning. This way of machining is good for many materials such as steel, aluminum, copper, ceramics, and magnesium alloys. Turning is widely used in the manufacture of shaft parts, threads, and conical parts, among others. If you need a reliable CNC turning service, then Yonglihao Machinery’s CNC turning is the best choice.
Drilling: Importance, Types, and Comparison of Drilling and Tapping
Drilling is a machining method used to create round holes in a workpiece. It is achieved by cutting the material with a rotating drill bit. Types of drilling operations include straight-hole drilling, deep-hole drilling, and reaming. Drilling and tapping differ. Drilling makes holes. Tapping adds threads to holes. Drilling is a preliminary step in many manufacturing processes and is critical to part assembly.
Milling: Operation, Tools, and Comparison to Other Processes
Milling removes material with a rotating cutter. It is good for machining many surfaces and shapes. Milling operations include flat milling, vertical milling, curve milling, and keyway milling. Milling has unique advantages over other machining processes. It’s for machining complex shapes and achieving high accuracy. You can select from a wide range of milling tools. They include end mills, ball end mills, and face mills. You should choose them based on the needs of the machining job.
Planning, broaching, and sawing: technologies and applications
Planing is a machining method for cutting large flat surfaces. It is good for surfaces that need further scraping. Like planning, broaching is a method for making complex holes and profiles. But, it is done by pulling a broach with a multi-toothed cutting tool. Sawing is different. It is for making short sections from bars and profiles. It uses sawing tools to cut the material to the desired length. These methods are effective for certain jobs. These jobs include making keyways, square holes, large flat surfaces, and cutting materials.
Advantages and Disadvantages of Machining Operations
Machining is central to manufacturing. Each method has its own good and bad points. Choosing the right machining process requires considering many factors. These include material properties, accuracy, productivity, and cost.
Machining Process | Advantages | Disadvantages |
Turning | Wide range of materials can be processed/ High production efficiency/Equipment is widely available | Material waste/High equipment cost/Limited to rotational parts |
Drilling | High accuracy for holes/Simple operation/Adaptable to almost all materials | Limited hole size without further processing/ Depth limitations |
Milling | Broad range of applications/- High precision/Variety of cutting tools | High equipment cost/Requires skilled operation |
Decision-making factors for selecting a machining process
When selecting a machining process, the following factors need to be considered:
- Material properties: Choose the right machining method. Do it based on the material’s hardness, toughness, and heat treatment properties.
- Machining accuracy and surface quality requirements: Making high-accuracy and quality parts may require specific machining methods.
- Machining efficiency and cost: Choose the cheapest machining method. Choose based on the production batch and cost budget.
- Part shape and size: Complex shapes or large-sized parts may require special machining equipment or techniques.
Considering all these factors. The best machining method will fit the specific needs. It can be selected to ensure quality and efficiency.
Summaries
In this article, we have explored many aspects of machining in detail. This includes a breakdown of operations like turning, drilling, milling, planing, broaching, and sawing. We also discussed the pros and cons of these machining operations. We talked about how to choose the right machining method for your production needs.
If you need reliable CNC machining services, choose Yonglihao Machinery. We have the expertise and technology to provide you with customised machining solutions.
FAQ
What determines the choice between conventional and non-conventional machining processes?
The choice between conventional and non-conventional machining processes is influenced by several factors:
- Material Compatibility: Conventional machining may struggle with hard, brittle, or heat-sensitive materials. Non-conventional methods excel with these materials.
- Complex Geometries: Non-conventional techniques can more easily handle intricate patterns and complex shapes.
- Surface Finish and Tolerances: Non-conventional methods can achieve finer finishes and tighter tolerances, ideal for critical applications.
- Heat-Affected Zone (HAZ): Non-conventional processes, such as laser cutting, minimize HAZ, beneficial for heat-sensitive materials.
- Speed and Efficiency: Conventional methods are faster. But, non-conventional methods offer precision and versatility. They are for specific applications.
How does material type influence the machining operation selected?
Material type heavily affects the choice of machining. This is due to factors like hardness, brittleness, and heat sensitivity. These properties might limit conventional machining. So, non-conventional techniques like EDM, laser cutting, or waterjet cutting are better for hard-to-machine materials.
Can non-conventional machining processes handle complex shapes better than conventional methods?
Yes, unusual machining processes are generally better at handling complex shapes. They are better at handling intricate geometries than conventional methods. Laser cutting and waterjet cutting can make detailed patterns with high precision. They do this without directly touching the workpiece. They are great for shaping complex shapes.