1. Introduction
For senior machinists, CNC tools are the core carrier for achieving precise machining, and the right selection and use of key tool types directly determine machining efficiency, product accuracy and production costs. Among the vast array of CNC tool types, milling cutters, turning tools, and drills are the three core types that every machinist must master due to their wide range of application scenarios and irreplaceable functions. Whether it is processing metal, plastic or composite materials, the reasonable combination and standardized use of these three types of tools are the basis for ensuring smooth production. Next, we will help you fully grasp the key knowledge of these three types of core CNC tools from the dimensions of defining functions, types of applications, selection and maintenance, combined with in-depth analysis of actual cases.
2. Tool type 1: milling cutter
2.1 Definition and function of milling cutters
The milling cutter is a rotating tool used in CNC milling processing, which realizes the processing of various shapes such as workpiece planes, grooves, steps, and curved surfaces through the rotational movement of the cutting edge and the feed motion of the workpiece. Its core function is to remove excess material from the workpiece and obtain a machining surface that meets the precision requirements, which is widely used in mold manufacturing, aerospace parts processing, auto parts production and other fields. According to industry data, milling accounts for more than 35% of the total machining, and the performance of the milling cutter directly affects the accuracy tolerance (up to ±0.005mm) and surface roughness (as low as Ra0.8μm).
2.2 Types and applications of milling cutters
Different types of milling cutters are suitable for different machining scenarios, the following are the most commonly used types of milling cutters and practical application cases:
| Types of milling cutters | Core application scenarios | Practical case |
|---|---|---|
| Flat bottom end mills | Plane milling, right-angle groove machining | An auto parts factory uses a φ20mm flat-bottom end mill to process the engine block plane, with a processing efficiency of 150cm³/min |
| Ball head milling cutter | Surface processing, mold cavity processing | A mold factory processes the mold cavity of the mobile phone shell and uses an R5mm ball head milling cutter to ensure the smoothness and contour accuracy of the curved surface |
| End mills | step surface machining, end face milling | A machine tool factory processes the step surface of the machine tool workbench, using a 4-flute end milling cutter, and completes the step surface processing in one forming to reduce the process flow |
2.3 Considerations When Selecting a Milling Cutter
The selection of milling cutters requires a combination of factors to avoid machining defects or inefficiency caused by improper selection, and the key considerations are as follows:
- Workpiece material: For processing high-strength steel, you need to choose a carbide milling cutter, and it needs to have a coating (such as TiAlN coating) to enhance wear resistance; For aluminum alloys, you can choose high-speed steel milling cutters or diamond-coated milling cutters to prevent sticking knives
- Machining accuracy requirements: For high-precision machining, you need to choose a milling cutter with a large number of cutting edges (4-6 flutes) and a small runout (≤0.002mm); for rough machining, you can choose a milling cutter with a small number of edges (2-3 flutes) to improve the efficiency of chip evacuation
- Machine tool performance: low-power machine tools need to choose small-diameter, light-cutting milling cutters to avoid overloading the machine tool; The high-speed machining center can be matched with a high-speed milling cutter to improve machining efficiency
3. Tool type 2: turning tool
3.1 Definition and function of turning tools
Turning tools are the core tools of CNC turning processing, which realize the processing of workpieces such as outer circles, inner holes, end faces, threads, etc. through the rotational movement of the workpiece and the linear feed motion of the turning tool. Its core function is to accurately cut rotating workpieces, and it is an essential tool for shaft and disc workpiece processing. In machining, turning accounts for about 40%, and high-quality turning tools can control the roundness tolerance of shaft workpieces within 0.003mm to meet the needs of high-precision assembly.
3.2 Types and applications of turning tools
According to the different processing parts and functions, turning tools are mainly divided into the following categories, combined with cases to illustrate their applications:
| Types of turning tools | Core application scenarios | Practical case |
|---|---|---|
| Outer cylindrical turning tools | Axial workpiece cylindrical machining, step outer cylindrical machining | A motor factory processes the outer circle of the motor spindle, using cemented carbide cylindrical turning, the processing speed reaches 200m/min, and the processing time of a single piece is shortened to 3 minutes |
| Inner hole turning tools | Inner hole processing and hole wall finishing of disc workpieces | A hydraulic parts factory processes the inner hole of the hydraulic cylinder and uses the inner hole turning tool for finishing to ensure that the roughness of the inner hole is Ra0.8μm to meet the sealing requirements |
| Thread turning tools | Workpiece threading (internal thread, external thread) | A fastener factory processes M20 bolt male threads, using special thread turning tools, and the thread accuracy reaches 6H level, which meets the national standard |
3.3 Turning tool use skills and maintenance
Proper usage techniques and standardized maintenance can significantly extend the life of the turning tool and improve the quality of the machine:
- Tips: When installing a turning tool, the tip should be at the same height as the center of the workpiece, and the deviation should not exceed 0.1mm, otherwise it will lead to an increase in cutting force and a decrease in machining accuracy; Adjust the cutting parameters according to the workpiece material, such as when processing No. 45 steel, the cutting speed is controlled at 120-150m/min, and the feed rate is 0.1-0.2mm/r
- Maintenance points: After the processing is completed, clean the chips on the turning tool edge in time to avoid chip residue and edge wear; Regularly check the wear of the cutting edge, and sharpen or replace the blade in time when the wear amount exceeds 0.2mm; When storing, the turning tool should be neatly placed to avoid collision between the blade and hard objects
4. Tool type three: drill bit
4.1 Definition and function of drill bits
The core function is to form a hole position on the workpiece that meets the requirements, laying the foundation for subsequent tapping, reaming and other processes. Drilling is one of the most basic and commonly used processes in machining, and according to statistics, more than 60% of mechanical parts need to be drilled. High-quality drill bits can ensure that the hole tolerance is ± 0.01mm, and the hole wall is smooth and burr-free.
4.2 Types and applications of drill bits
Different types of drill bits are suitable for different drilling needs, and the common types and application cases are as follows:
| Types of drill bits | Core application scenarios | Practical case |
|---|---|---|
| Twist Diamond | Ordinary hole drilling, batch drilling processing | A furniture hardware factory processes screw holes in batches, using φ5mm high-speed steel twist drills, with a drilling efficiency of 30 per minute, and a pass rate of 99.8% |
| Center drill | Drilling positioning, prefabricated center hole | Before processing the spindle through hole, a shaft processing plant first prefabricated the center hole with a center drill to ensure that the coaxiality error of the subsequent drilling ≤ 0.005mm |
| Deep hole drilling | Deep Hole Machining (Hole Depth/Aperture >5) | A petroleum machinery factory processes deep holes in drill pipes, using deep hole drilling, with a hole depth of 200mm and a hole diameter of φ15mm, to ensure the straightness and surface roughness of the deep hole |
4.3 Selection and maintenance of drill bits
The selection and maintenance of drill bits directly impact the quality and longevity of the drill hole, and the key points are as follows:
- Key points of selection: choose the drill bit according to the accuracy of the hole, ordinary holes can choose twist drills, high-precision holes need to choose precision drills or alloy drills; The drill bit material is selected according to the thickness and hardness of the workpiece, the carbide drill bit is selected for thick plate or hard material, and the high-speed steel drill bit is selected for thin plate or soft material
- Maintenance points: avoid dry drilling of the drill bit, and fill the cutting fluid during processing to reduce the temperature and reduce wear; the drill bit is sharpened in time after use to ensure the sharpness of the cutting edge; When storing, the drill bits should be classified according to specifications to avoid bending and deformation
5. Conclusion
Milling cutters, turning tools, and drills are the three core CNC tool types, which are the basis for machinists to carry out precise machining. Mastering their definition functions, types and applications, and selection and maintenance skills can effectively improve processing efficiency, ensure product accuracy, and reduce production costs. In actual processing, it is necessary to reasonably select the type based on factors such as workpiece material, processing requirements, machine tool performance, etc., and strictly follow the use and maintenance specifications. With the continuous development of CNC machining technology, tool materials and structures are also constantly upgrading, and machinists need to continuously learn new tool knowledge to adapt to the development needs of the industry.
Yigu Technology Perspective
As an enterprise deeply involved in the field of CNC machining, Yigu Technology believes that high-quality CNC tools are the core support for achieving efficient and precise machining, and the reasonable adaptation and standardized use of milling cutters, turning tools, and drill bits are the key links to improve production efficiency. We always pay attention to the innovation and upgrading of tool technology, and when providing customers with machining solutions, we will recommend suitable tool types and specifications based on actual machining scenarios to help customers optimize the machining process and reduce production costs. In the future, with the advancement of intelligent manufacturing, tools will develop in the direction of intelligence and precision, and Yigu Technology will continue to integrate high-quality resources to provide customers with more valuable tool-related solutions.
FAQ
Q1: What are the core differences in the selection of milling cutters when processing different materials?
When processing difficult-to-machine materials such as high-strength steel and stainless steel, it is necessary to choose a milling cutter made of cemented carbide material + wear-resistant coating such as TiAlN, with a number of cutting edges of 4-6 blades to ensure cutting stability; When processing soft materials such as aluminum alloys and plastics, you can choose high-speed steel milling cutters or diamond-coated milling cutters with a number of 2-3 cutting edges to improve chip removal efficiency and prevent knife sticking.
Q2: What is the importance of the same height as the center of the workpiece when using turning tools?
The equal height of the tool tip and the center of the workpiece is the key to ensuring the turning accuracy: if the tip is higher than the center, it will lead to an increase in the actual rake angle of the cutting edge, a decrease in the back angle, an acceleration of tool wear, and easy to produce chipping edges; If the tip of the tool is lower than the center, it will lead to a decrease in the rake angle, an increase in the aftering angle, an increase in cutting force, and the workpiece is prone to defects such as taper and roundness deviation, and the deviation needs to be controlled within 0.1mm.
Q3: What is the role of cutting fluid in drill bit maintenance?
Cutting fluid plays three core roles in drill bit maintenance: first, cooling, reducing the high temperature generated during the drilling process, and avoiding the hardness loss and deformation of the drill bit due to overheating; the second is lubrication, which reduces the friction between the drill bit and the workpiece and chips, reduces wear and improves the smoothness of the hole wall; The third is chip evacuation, which helps to take away chips and avoid chip residues blocking the hole and damaging the drill bit and workpiece.
Q4: How long is the service life of milling cutters, turning tools, and drill bits?
The service life is greatly affected by the workpiece material, cutting parameters, and maintenance: when carbide milling cutters process No. 45 steel, the service life is about 80-120 minutes; when carbide turning tools process ordinary steel, the service life is about 100-150 minutes; when high-speed steel twist drills process soft materials, the service life is about 50-80 minutes, and when processing hard materials, it is about 30-50 minutes, and when the wear exceeds 0.2mm, it needs to be sharpened or replaced in time.
