How to Properly Select Cutting Tools for CNC Machine Tools

The selection of CNC cutting tools and the determination of cutting parameters are critical components of CNC machining processes.
It not only affects the machining efficiency of CNC machine tools but also directly impacts machining quality. Today, our editor will...
Let me walk you through how to properly select cutting tools for CNC machine tools—hopefully this will be helpful.
  Currently, many CAD/CAM software packages offer automatic programming capabilities; these programs—
Typically, the programming interface provides prompts regarding process planning issues, such as tool selection and machining paths.
Including planning and cutting parameter settings, once the programmer has configured the relevant parameters, the system can automatically
Generate the NC program and transmit it to the CNC machine tool to complete the machining process. Therefore, in CNC machining, tool selection
The selection of cutting parameters and the determination of cutting conditions are carried out in an interactive human–machine interface, which differs from conventional machine tool machining.
This stark contrast also necessitates that programmers master tool selection and the determination of cutting parameters.
The basic principle is to fully consider the characteristics of CNC machining during programming, enabling the correct selection of cutting tools and
Cutting parameters.
  The selection of CNC cutting tools and the determination of cutting parameters are important aspects of CNC machining processes.
Moreover, it not only affects the machining efficiency of CNC machine tools but also directly impacts the quality of machining.
The development of CAD/CAM technology has made it possible to directly utilize CAD design data in CNC machining.
This has become possible, particularly with the integration of DNC system microcomputers and CNC machine tools, enabling design and process…
The entire planning and programming process is carried out on a computer, and generally there is no need to produce dedicated documentation.
Art document.
  Currently, many CAD/CAM software packages offer automatic programming capabilities; these programs—
Typically, the programming interface provides prompts regarding process planning issues, such as tool selection and machining paths.
Including planning and cutting parameter settings, once the programmer has configured the relevant parameters, the system can automatically
Generate the NC program and transfer it to the CNC machine tool to complete machining.
  Therefore, tool selection and cutting parameter optimization in CNC machining are performed in an interactive human–machine environment.
completed afterward, which stands in stark contrast to conventional machine tool machining and, at the same time, necessitates that programmers must
One must master the basic principles of tool selection and cutting parameter determination, and fully consider CNC machining during programming.
The characteristics of the workpiece enable the correct selection of cutting tools and cutting parameters.
  Types and Characteristics of Commonly Used Cutting Tools in CNC Machining
  CNC cutting tools must be compatible with the high-speed, high-efficiency, and highly automated characteristics of CNC machine tools.
The selection should generally include general-purpose cutting tools, universal tool holders, and a small number of specialized tool holders. The tool holder must be capable of connecting...
Cutting tools are mounted directly on the machine tool’s spindle, and as a result have gradually become standardized and serialized. The classification of CNC cutting tools is...
There are various types of tools. Based on the tool structure, they can be classified as: ① solid-type; ② insert-type, which uses welding.
or mechanical clamping connections; mechanical clamping connections can further be classified into non-indexable and indexable types; ③ special types, such as
Composite tools, vibration-damping tools, and the like. Based on the materials used in tool manufacturing, they can be classified as: ① high-speed
Steel cutting tools; ② cemented carbide cutting tools; ③ diamond cutting tools; ④ cutting tools made of other materials, such as cubic boron nitride.
Cutting tools, ceramic cutting tools, and the like. Based on the cutting process, they can be classified as: ① turning tools, further divided into external turning and internal…
including drills, threaded tools, and cutting tools; ② drilling tools, including drill bits, reamers, taps, etc.; ③
Boring tools; ④ milling tools, etc. In order to meet the requirements of CNC machine tools for tool durability, stability, and ease
requirements such as adjustment and interchangeability, indexable insert tools with mechanical clamping have seen widespread application in recent years, in terms of quantity
It accounts for 30% to 40% of the total CNC cutting tools, and its metal removal volume represents 80% to 90% of the total.
  CNC cutting tools have many different requirements compared with tools used on conventional machine tools, primarily
It should possess the following characteristics: ① good rigidity (especially for roughing tools), high precision, and resistance to vibration and thermal deformation.
Small; ② Good interchangeability, facilitating quick tool changes; ③ Long tool life and stable, reliable cutting performance; ④ Cutting tools
Its dimensions are easy to adjust, thereby reducing tool-change setup time; ⑤ the cutting tool should be capable of reliably breaking or curling the chip.
Chips, to facilitate chip evacuation; ⑥ Serialization and standardization, to facilitate programming and tool management.
  Selection of CNC Machining Tools
  The selection of cutting tools is performed in the human–machine interaction mode of CNC programming. It should be based on the machine tool.
machining capability, workpiece material properties, machining operations, cutting parameters, and other relevant factors
Select cutting tools and tool holders correctly. The general principle for tool selection is: easy installation and adjustment, good rigidity,
High durability and precision. While meeting the machining requirements, select the shortest possible tool holder whenever possible, in order to
Enhance the rigidity of tool machining.
  When selecting cutting tools, their dimensions must be matched to the surface dimensions of the workpiece being machined.
In manufacturing, end mills are commonly used for machining the peripheral contours of planar parts; when milling flat surfaces, one should select
Carbide insert end mills; when machining bosses and slots, select high-speed steel end mills; for machining the rough workpiece surface.
When performing rough machining of holes, a corn milling cutter with carbide inserts can be selected; for certain three-dimensional surfaces and
Machining of contoured profiles with varying taper angles typically employs ball-end mills, toroidal mills, tapered mills, and face mills.
Milling cutter.
  When machining freeform surfaces (molds), since the cutting speed at the tip of a ball-end mill is
Therefore, to ensure machining accuracy, the cutting step is generally set as a close pitch at the tool tip; hence, ball-end mills are commonly used.
for the finish machining of curved surfaces. In contrast, flat-end cutters outperform ball-end cutters in both surface quality and cutting efficiency.
The first cut, therefore, as long as overcutting is avoided, whether for roughing or finishing of curved surfaces...
When machining, flat-end mills should always be given priority. In addition, the tool’s durability and precision are closely related to its price.
The significance is enormous; it must be emphasized that, in most cases, selecting high-quality cutting tools, although it increases
While the tool cost has increased, the resulting improvements in machining quality and efficiency can benefit the entire
Processing costs have been significantly reduced.
  On the machining center, various cutting tools are stored in the tool magazine and selected as required by the program.
cutting tools and tool-changing operations. Therefore, standard tool holders must be used to enable drilling, boring, reaming, milling, and other machining operations.
The standard tool used for setup is quickly and accurately mounted onto the machine tool spindle or tool magazine. The programmer should…
Understand the structural dimensions, adjustment methods, and adjustment ranges of the tool holders used on machine tools, so as to facilitate programming.
Determine the radial and axial dimensions of the cutting tool. Currently, machining centers in China use the TSG tool system.
The tool shanks come in two types: straight shanks (available in three specifications) and tapered shanks (available in four specifications), totaling 16 different applications.
The handle of the knife on the way.
  During the machining process with economical CNC machine tools, due to tool grinding, measurement, and replacement
Most operations are performed manually, which consumes a significant amount of auxiliary time; therefore, tool sequencing must be arranged rationally.
Column order. Generally, the following principles should be followed: ① Minimize the number of tools; ② Clamp a single tool
Afterward, all machining steps that can be performed should be completed; ③ Roughing and finishing tools should be used separately.
use, even if the cutting tools are of the same size and specification; ④ mill before drilling; ⑤ perform finish machining of curved surfaces first, then
Perform fine machining of the 2D contour; ⑥ Wherever possible, full use should be made of the CNC machine tool’s self-
Tool-changing function to improve production efficiency, among other benefits.
  Determination of Cutting Parameters During Machining
  The principle for the rational selection of cutting parameters is: during rough machining, the primary objective is generally to maximize productivity.
However, economic considerations and machining costs should also be taken into account; during semi-finishing and finishing, it is essential to ensure that the…
While ensuring workpiece quality, balance cutting efficiency, cost-effectiveness, and machining costs. Specific values should be determined based on
Refer to the machine tool manual and the cutting parameters handbook, and make decisions based on experience. Specifically, the following factors should be considered:
Plain:
  ① Cutting depth t. When the rigidity of the machine tool, workpiece, and cutting tool permits, t is equal to
Machining allowance is an effective measure for improving productivity. To ensure the machining accuracy of parts,
and surface roughness; generally, a certain amount of allowance should be reserved for finish machining. The finish-machining allowance for CNC machine tools
The dimensions can be slightly smaller than those of conventional machine tools.
  ② Cutting width L. Generally, L is proportional to the tool diameter d and inversely proportional to the cutting depth.
Comparison. In the machining process of economical CNC machine tools, the typical range for L is: L = (0.6～
0.9)d.
  ③ Cutting speed v. Increasing v is also a measure to improve productivity, but v is related to the cutting tool.
The relationship with tool life is quite close. As v increases, tool life drops sharply; therefore, v...
The selection primarily depends on tool life. In addition, cutting speed is also closely related to the workpiece material.
For example, when milling the alloy steel 30CrNi2MoVA with an end mill, the cutting speed v can be taken as approximately 8 m/min.
Right; however, when milling aluminum alloy with the same end mill, the cutting speed v can be selected at 200 m/min or higher.
  ④ Spindle speed n (r/min). The spindle speed is generally selected based on the cutting speed v. Calculation formula:
The formula is: v = πnd/1000. CNC machine tools typically have a spindle speed override (multiplier) function on the control panel.
The speed-adjustment switch allows for integer-multiple adjustments of the spindle speed during machining.
  ⑤ Feed rate vF. vF should be determined based on the machining accuracy and surface roughness requirements of the part, in accordance with
and is selected based on the tool and workpiece materials. Increasing the feed rate (vF) can also enhance production efficiency. Machined surface
When the surface roughness requirement is low, a larger feed rate, vF, can be selected. During machining, vF can also be adjusted via the machine tool.
Manual adjustments are made using the trim switches on the control panel; however, the maximum feed rate is limited by the machine’s rigidity.
limitations such as those related to the performance of the positioning and feed systems.
  With the widespread application of CNC machine tools in actual production and the establishment of quantified production lines, numer...
Control programming has become one of the key issues in CNC machining. During the process of developing CNC programs,
In this context, it is necessary to select tools and determine cutting parameters in real time during human–machine interaction. Therefore, the programmer
Operators must be familiar with the methods for selecting cutting tools and the principles for determining cutting parameters, thereby ensuring the machining of parts.
work quality and processing efficiency, fully leverage the advantages of CNC machine tools, and enhance the economic benefits of enterprises and
Production level