With various types of lathe cutting tools available, each with distinct features and designs tailored for specific cutting operations, selecting the right tool necessitates a comprehensive understanding of its capabilities.
In this article we dive into the common types of tools used for lathes, detailing their designs, unique features, and practical applications to aid in making informed decisions when choosing the appropriate tool for your lathe operations.
Tool Categories
The lathe cutting tools can be categorized into four main categories based on material, operations, structure, and feed direction. These categories help in understanding the different types of tools and their applications.
1. Material
Different materials have unique properties that determine the performance and suitability of the tools for specific applications. The common materials used for lathe cutting tools are high-speed steel (HSS), carbide, diamond, and cubic boron nitride (CBN). Each material has its advantages and is suited for different machining tasks.
High Speed Steel (HSS)
High-speed steel (HSS) is a popular material used for lathe cutting tools due to its excellent combination of hardness, toughness, and heat resistance. HSS tools can withstand high cutting speeds and maintain their sharpness for longer periods. They are suitable for a wide range of materials and operations, including turning, facing, and grooving. HSS tools can be easily sharpened and are cost-effective compared to other materials. With proper maintenance and care, HSS tools can provide consistent and reliable performance in metalworking applications.
Carbide
Carbide is another widely used material for lathe cutting tools. It is known for its hardness and wear resistance, making it suitable for machining hardened steels, stainless steels, and other tough materials. Carbide tools maintain their sharpness for longer durations and require less frequent sharpening compared to HSS tools. They are often used as inserts, which are replaceable cutting tips mounted on toolholders. Carbide inserts offer cost-effective solutions as only the inserts need to be replaced when worn out. These tools provide high cutting speeds, increased productivity, and improved surface finishes in metalworking operations.
Diamond
Diamond is the hardest material known to man, making it ideal for cutting tools that require exceptional hardness and wear resistance. Diamond tools can effectively machine materials such as hardened steels, ceramics, and composites. They provide superior surface finishes and can withstand high cutting speeds. However, diamond tools are more expensive than other materials and are typically used in specialized applications where precision and high-quality results are vital. Their exceptional performance and longevity justify the investment for industries that demand the highest quality in metalworking.
Cubic Boron Nitride
Cubic boron nitride (CBN) is a synthetic material that is second only to diamond in terms of hardness. It is known for its exceptional heat resistance and ability to withstand high cutting speeds. CBN tools are commonly used in machining applications that involve hard materials like cast iron and hardened steels. They provide excellent tool life and improved productivity in demanding industrial settings. While CBN tools may be more expensive than other materials, their performance and durability make them a valuable investment for industries that require reliable and efficient metalworking tools.
2. Operations
Different tools are used for turning, chamfering, threading, facing, forming, grooving, boring, and knurling. Each operation requires a specific tool design and geometry to achieve the desired results.
Turning Tools
Turning tools are among the most commonly used lathe cutting tools. They are used to remove material from the workpiece, resulting in a reduction in diameter and the creation of cylindrical shapes. Turning tools can be further classified into rough turning tools and finish turning tools. Rough turning tools are used to remove large amounts of material quickly, while finish turning tools are used for final shaping and achieving smooth, finished surfaces. These versatile tools are essential in metal lathe operations and are available in various sizes and designs to accommodate different turning applications.
Chamfering Tools
Chamfering tools are used to create beveled edges or chamfers on the workpiece. Chamfering is often done to remove sharp edges, improve aesthetics, or provide a better fit between parts. Chamfering can be performed using turning tools by setting them at the appropriate angle to the workpiece. However, specialized chamfering tools are also available, offering precise control and efficiency in producing consistent chamfer dimensions. These tools are widely used in metalworking and machine tool applications, ensuring the production of high-quality parts with chamfered edges.
Thread Cutting Tools
Thread cutting tools are essential for creating screw threads on cylindrical parts. These tools are designed to produce precise thread patterns with the desired thread angle and pitch. Thread cutting tools can include taps for creating internal threads and dies for creating external threads. Tapping is the process of creating internal threads using a tap, while threading involves using a die to create external threads. These tools require proper alignment and control to ensure accurate thread profiles and dimensions. Thread cutting tools are widely used in industries that require threaded components, such as automotive, aerospace, and manufacturing.
Facing Tools
Facing tools are used to create flat surfaces on the workpiece by removing a thin layer of material. Facing operations are commonly performed to ensure smooth and parallel surfaces, square ends, or to prepare surfaces for subsequent operations. Facing tools typically have a cutting edge perpendicular to the workpiece and remove material in a radial direction. These tools are essential for achieving precise dimensions and surface finishes in metalworking applications. Facing tools are available in different sizes and designs to accommodate various workpiece sizes and facing requirements.
Forming Tools
Forming tools combine turning and grooving functions to shape the workpiece in a single operation. These tools are designed to create complex shapes or profiles on the workpiece, eliminating the need for multiple tool changes. Forming tools offer increased accuracy and reduced cycle time compared to using separate turning and grooving tools. They are commonly used in metal shaping applications where intricate shapes or profiles are required. Forming tools are available in different geometries and sizes to accommodate various forming operations.
Grooving Tools
Grooving tools are used to create grooves on cylindrical surfaces of the workpiece. These grooves can serve various purposes, such as providing clearance for O-rings, retaining rings, or snap rings. Grooving tools come in different shapes and sizes to accommodate different groove dimensions and profiles. Common types include V-shaped and square cutting tools. Internal grooving tools are designed specifically for creating grooves inside bores or holes. Grooving tools are essential in metalworking applications that require precise groove dimensions and profiles.
Boring Tools
Boring tools are used to enlarge or refine existing holes in the workpiece. These tools typically consist of a boring bar with a cutting tool at its end. Boring tools are used to achieve precise diameter and surface finishes in bores or holes. They are commonly employed in applications where tight tolerances and high accuracy are required. Boring tools can be used to create through-holes, blind holes, or tapered holes. They are available in various sizes and designs to accommodate different hole diameters and depths.
Knurling Tools
Knurling tools are a type of lathe cutting tool used to create texture on a workpiece. They consist of two or more metal rolling wheels with embossed patterns. These tools are commonly used to increase the grip of a product by making indents on its surface. Knurling can be done on various materials such as metal, plastic, or wood.
To use a knurling tool, the workpiece is held securely in the lathe chuck. The knurling tool is then brought into contact with the workpiece, and pressure is applied to create the desired indentation pattern. The pattern can be straight, diamond-shaped, or any other design depending on the type of knurling tool used.
Knurling tools are often used in applications where a better grip is required, such as on the handles of tools or machine parts. They are also used in the automotive industry to improve the grip on steering wheels or gear shift knobs. Overall, knurling tools are a must-have for any metalworking lathe to add texture and functionality to the finished products.
3. Structure
Lathe cutting tools can be categorized based on their structure. These categories include single-body tools, welding lathe cutting tools, and clamp lathe cutting tools. Each type of lathe cutting tool has its own advantages and is suitable for different machining applications. The choice of tool depends on the specific requirements of the project and the desired outcome.
Single Body Tools
Single-body tools are a type of lathe cutting tool that is made from a single piece of material. They are designed to have a specific shape, size, and geometry, making them the most common and versatile type of lathe cutting tool.
These tools are known for their speed and strength, making them suitable for a wide range of machining operations. They can be made from various materials, including high-speed steel (HSS), which is a popular choice due to its hardness, strength, and wear/heat resistance.
HSS single-body tools are capable of handling rough and semi-finish machining operations. They are ideal for removing large amounts of material in a single pass or creating rough shapes on the workpiece. HSS tools are widely used in industries such as automotive, aerospace, and general metalworking due to their durability and performance.
Welding Tools
Welding lathe cutting tools are a type of lathe cutting tool that consists of a head and rod made from different materials joined through welding. The head, or flank, is typically made from a material such as carbide, known for its strength and durability, while the body can be made from various metals.
These tools are designed to deliver less cutting force compared to single-body tools due to the material difference. However, they still provide effective cutting capabilities for a wide range of machining operations.
Welding lathe cutting tools are commonly used in applications where the cutting force needs to be controlled or reduced, such as when working with delicate or intricate workpieces. They are also used when specific tool geometries or cutting angles are required.
The use of welding lathe cutting tools allows for flexibility and customization, as different combinations of materials can be used to suit specific cutting requirements. These tools are a valuable addition to any metalworking lathe and provide versatility in machining operations.
Clamp Tools
Clamp lathe cutting tools are a type of lathe cutting tool that is formed by placing the insert, or cutting tool, on a handlebar. The cutting tool is clamped securely in place, allowing for easy replacement and flexibility in machining operations.
The clamp lathe cutting tool design allows for efficient chip removal and improved cutting performance. The properties of these tools, such as strength and durability, depend on the type of inserts used. Different types of indexable inserts can be used, depending on the specific machining requirements.
These tools are known for their dexterity and versatility, making them suitable for a wide range of cutting operations. They are commonly used in industries such as automotive, aerospace, and general metalworking.
The ability to replace the inserts in clamp lathe cutting tools makes them cost-effective and efficient in long-term use. They provide a reliable and precise cutting solution for various metalworking lathe applications.
4. Feed Direction
The two main types of lathe cutting tools based on feed direction are right-hand tools and left-hand tools. The choice between right-hand and left-hand tools depends on the specific machining requirements and the desired outcome. Both types of tools provide efficient cutting capabilities and can be used in a variety of metalworking applications.
Right-Hand Tools
Right-hand lathe cutting tools are a type of cutting tool that removes materials when transporting them from right to left. These tools have a design similar to the human hand, with the right thumb indicating the direction of the feed, and the main cutting edge on the left side of the tool.
Left-Hand Tools
Left-hand lathe cutting tools are a type of cutting tool that removes materials when transporting them from left to right. According to the human hand design, the left thumb denotes the feed direction, and the main cutting edge is on the right side of the tool.
Round Nose Tools
Round nose lathe cutting tools are a type of cutting tool that can move from left to right or right to left. These tools have no side rake and back rake angles, making them suitable for machining operations that require a smooth surface.
Components
A lathe cutting tool consists of several components that work together to provide efficient cutting capabilities. These components include the shank, face, flank, cutting edge, tool nose, rake angle, and relief angle.
Shank is the part of the cutting tool that connects to the lathe. It is the thickest part of the tool and provides stability during machining operations.
Face is the part of the cutting tool on which the chip flows during lathing operations. It allows for efficient chip evacuation and reduces the heat generated during cutting.
Flank is the part of the cutting tool that opposes and interacts with the workpiece. It forms the cutting edge and determines the direction and quality of the cut.
Cutting Edge is the part of the tool responsible for the cutting action. It can have multiple surfaces and angles depending on the tool type and application.
Tool Nose is the intersection of the major and minor cutting edges. It has a curvature that increases its strength, longevity, and ability to make a smooth cut.
Rake Angle is the angle formed by the cutting edge and the line perpendicular to the tool’s base. It determines the direction of the chip flow and affects the cutting performance.
Relief Angle is the angle that prevents rubbing between the major flank and workpiece and between the minor flank and workpiece. It improves cutting efficiency and reduces tool wear.
By understanding the components of a lathe cutting tool, you can make informed decisions when selecting and using the right tool for your metalworking project.
Select The Right Tool
Selecting the right lathe cutting tool is crucial for achieving accurate and precise results in metalworking projects. There are several factors to consider when choosing the right tool, everything from the coating to the type of turning operation.
Lathe Tools Coating
There are several types of coatings available, including tin coating, titanium nitride (TiN) coating, titanium carbide (TiC) coating, and aluminum oxide coating.
Tin provides increased hardness and wear resistance to the cutting tool. It also improves chip flow and reduces friction during machining operations, resulting in improved tool life and better surface finish.
Titanium Nitride (TiN) offers excellent hardness, wear resistance, and high-temperature stability. It provides a protective layer on the cutting tool, reducing tool wear and extending tool life.
Titanium Carbide (TiC) is known for its excellent wear resistance and thermal stability. It is ideal for high-speed machining and heavy-duty cutting applications.
Aluminum Oxide provides high temperature and oxidation resistance. It improves tool life and performance in high-temperature machining operations.
Coatings are applied to the external parts of lathe cutting tools to enhance their mechanical properties and aesthetics. Coated lathe cutting tools generally have a longer tool life compared to uncoated tools.
Workpiece Material
The selection of the right lathe cutting tool depends on the material of the workpiece. Different materials have different mechanical properties, which require specific cutting tool characteristics. When selecting a lathe cutting tool, consider the hardness, toughness, and heat resistance of the workpiece material.
Hard Materials require cutting tools with high hardness and wear resistance to prevent tool wear and chipping.
Soft Materials may require tools with different cutting characteristics to ensure efficient cutting performance.
It is important to choose a cutting tool that is compatible with the workpiece material to achieve accurate and precise results. Using the wrong tool can result in poor surface finish, tool wear, and potential damage to the workpiece.
Desired Turning Operation Types
Some common turning operation types include rough turning, finish turning, facing, chamfering, and contouring. Each operation requires a specific set of skills and tooling to achieve the desired outcome.
Rough Turning involves removing large amounts of material from a workpiece in a single pass. It is typically used to create rough shapes or prepare surfaces for subsequent finishing operations.
Finish Turning involves removing small amounts of material from a workpiece to create a smooth, finished surface. It is used to achieve tight tolerances and precise dimensions.
Facing is the process of reducing the workpiece length to form the desired parts. It involves using the cutting tool to cut off the part perpendicularly.
Chamfering is the process of producing a slanting edge on the cylindrical workpiece. It is used to reduce damage to sharp edges and improve the aesthetics of the workpiece.
Contouring involves shaping or contouring the workpiece to create complex shapes. It requires tools with specific geometries and cutting angles.
By considering the desired turning operation types, you can select the right lathe cutting tool that will deliver efficient and precise cutting capabilities for your metalworking project.
Lathe Cutting Tools
Whether it’s selecting the right tool based on material, operation, structure, or feed direction, each plays a vital role in achieving precision and quality in metalworking. Factors like coating, workpiece material, and desired operation types further influence tool selection.
Being familiar with the components and available cutting operations for lathes empowers machinists to optimize their processes and enhance productivity.