When it comes to the selection of cutting tools, it is very important to choose the right and appropriate tool according to the characteristics of the tool itself, processing equipment, and processing materials, because the right choice can significantly improve work efficiency and material processing quality. However, there are a wide variety of tools on the market, with very different materials and functions, so in order to enable you to make a more accurate choice, we will launch a series of tweets. In this series of tweets, we will discuss in depth how to choose the most suitable cutting tool for your needs. First, let's understand the basic concept of cutting tools in more detail.

 

 

First, the three categories of cutting tools:

1. According to the composition of the tool material can be divided into:

➢ Diamond tool (Diamond) : can be used for non-metallic hard and brittle materials such as graphite, high-wear-resistant materials, composite materials, high-silicon aluminum alloy and other ductile non-ferrous metal materials precision processing.

➢ Cubic Born Nitride tool (Cubic Born Nitride) : PCBN tool is most suitable for high-speed cutting of cast iron, hardened steel and other materials.

➢ Ceramic Tools: suitable for the processing of cast iron and high hardness alloys, can also be milling, planing, intermittent cutting and rough drawing and other impact processing.

➢ Cemented Carbide Tools: Usually used for cutting, milling, drilling and processing various materials, including metal, wood, plastic and so on.

➢ High-speed Steel tools (High Speed Steel) : In complex tools, especially manufacturing hole processing tools, milling tools, thread tools, broach, cutting tools and other blade complex tools, high-speed steel still occupies a major position.

Carbon and Alloy tool Steel (Alloy Steel) : suitable for the production of cutting tools and tools to withstand the impact load of soft materials, suitable for the production of punches, scissors, can also make woodworking tools.

 

 

2. According to the processing method can be divided into:

➢ Turning Tools

➢ Drilling Tools

➢ Milling Tools

➢ Gear Cutting Tools

➢ Formed Tools (Formed Tools)

➢ other Tools

 

3. According to the tool structure can be divided into:

➢ Integral tool

➢ Welding Tools

➢ Indexable tool

➢ Other Tools

 

 

Second, the necessary performance of cutting tools:

Cutting tools are tools used to remove materials from workpieces and are commonly used for cutting, milling, drilling, and machining various materials, including metal, wood, plastic, etc. The performance and quality of cutting tools are critical to industrial manufacturing and processing tasks, so the following properties must be available:

1. High hardness and wear resistance

The hardness of the tool material is generally greater than 60HRC (it should generally be greater than the hardness of the workpiece material). The wear resistance of the tool material refers to the ability to resist wear, the higher the hardness of the tool, the higher the wear resistance. In addition to hardness, wear resistance is also related to the chemical composition, strength, toughness and microstructure of the material.

2. Sufficient strength and toughness

During the cutting process, the cutting part of the tool bears a large cutting load, especially in the intermittent cutting process, it must withstand the thermal and mechanical impact of the cycle, and the common forms of damage of the tool are damage such as breakage, fracture, etc. The tool material must have sufficient strength and toughness.

3. High thermal stability

Also known as high heat resistance, it is an important sign of measuring the cutting performance of tool materials, which refers to the ability of tool materials to maintain hardness, wear resistance, strength and toughness at high temperatures. In addition to high thermal stability, tool materials should also have good high-temperature oxidation resistance and diffusion resistance.

4. Good thermal physical characteristics and thermal shock resistance

Good thermal conductivity, large heat capacity is conducive to the transfer of cutting heat, reduce the cutting temperature; During intermittent cutting, the tool is subjected to cyclic thermal shock, which is easy to crack and break, so the tool material should have excellent thermal shock resistance. The smaller the coefficient of thermal expansion is, the smaller the thermal deformation is, which is conducive to reducing the thermal stress.

5. Good manufacturability

It refers to the good forging performance, machining performance and heat treatment performance, which is convenient for the manufacture of tools.

 

Table.1 Main performance indexes of various tool materials

Third, the cutting tool selection should pay attention to the four main points:

1. Cutter head type

Different kinds of cutting tools, the purpose and object of processing are different, and the tool type refers to that the same kind of cutting tools can process different products because of different tool heads. Common cutter head types are: flat end milling cutter, round nose milling cutter (R Angle cutter), ball end milling cutter, chamfer milling cutter, slotting milling cutter and so on. Taking the drill as an example, the pointed drill that can simply drill the groove with the tool head, and the flat drill with the flat drilling, the former has strong penetration, and the latter can place the relevant parts inside the hole, all in accordance with the user's needs.

2. Number of tool blades

The number of blades determines how much a cutting tool can cut at a time, and the amount of chip removal, cutting strength and cutting accuracy, the most common tools on the market with 2 to 8 blades. Tools with fewer blades can cut a larger area and hold more debris, and the blade part can withstand greater resistance, so it often plays the role of a pioneer, used in the first cut that needs to cut a large number of parts. A large amount of cutting means that it is not possible to do subtle trimming, so the tool with a large number of blades comes in handy, limiting the amount of chip removal and cutting strength to improve the accuracy of the cutting, which is very suitable for use in the dressing after the second tool. In the case of end milling cutters, depending on the number of blades selected, they can be used to perform grooving, roughing or finishing processes.

 

		2-blade	3-blade	4-blade	6-blade
Characteristic	Advantage	The chip discharge is smooth, the longitudinal feed processing is easy and the cutting force is small	Smooth chip discharge and easy longitudinal feed processing	High rigidity	High rigidity Excellent cutting edge durability
	Shortcoming	Low rigidity	External diameter measurement is difficult	Chip discharge is not smooth	Chip discharge is not smooth
Applicantion		It is widely used for grooving, side machining and hole machining	Used for grooving, side machining, heavy cutting and finishing	For shallow groove, side machining, finishing;	High hardness material processing

 

3. Blade length

Some people may ignore the length of the tool body, but in fact, it is related to the size and depth of the object to be cut, if the depth of the object to be cut is deep, not long enough the tool body can not be cut, so you need to pay attention to the purchase. However, the tool body is not the longer the better, the need to adjust the cutting Angle, speed, and speed according to the material of the tool body to avoid the situation of breaking the blade or breaking the knife.

 

 

4. Tool material

The material of the cutting tool determines what kind of object it can cut. Common tool materials include: high-carbon tool steel with less heat resistance, which is often used for slow cutting tools such as reamer; The high speed steel with both hardness and toughness is suitable for drill bits, can withstand higher cutting speed processing steps, extremely hard, but the price is also higher sintered tungsten carbide steel, suitable for split end milling cutter, can be used to cut hard materials. Considering the cost and production efficiency, there is no best only the most appropriate material.

 

In the following tweets, we will explore in more depth the characteristics of each cutting tool, the key factors when choosing, and how to use them correctly in different applications. Whether you are a professional craftsman or a beginner, we will provide you with useful information to help you choose and make the most of the tool that best suits your needs. Follow our series of tweets for more cutting tool expertise and tips!