Lathe Cutting Tools: Different Types of Tools for Turning
Lathe cutting tools are indispensable in the field of machining and manufacturing. These tools, which perform cutting operations on a lathe machine, shape and modify metal, wood, and other materials into precise specifications. Understanding the different types of lathe tools and their applications not only enhances efficiency but also ensures quality in the finished products.
Types of Materials for Lathe Cutting Tools
Lathe cutting tools are specialized tools used in turning operations on a lathe machine. They are classified based on various factors, including the type of material from which they are made. Each material offers different benefits and is suitable for various machining conditions, tool life, and workpiece materials. Here are some common types of materials used for lathe cutting tools:
-High-Speed Steel (HSS) Tools
Description and Properties: High-Speed Steel (HSS) tools are renowned for their durability and versatility. They can withstand higher temperatures without losing their temper, which allows for faster machining speeds compared to traditional carbon steel tools.
Common Applications: HSS tools are commonly used for general turning operations, threading, and other tasks where sharp edges and fine finishes are crucial. They are particularly favored in custom job shops for their adaptability.
-Carbide Tools
Advantages over HSS: Cemented carbide normally consists of tungsten carbide particles held in a metallic binder. Its hardness and wear resistance can support productive turning, but tool life depends on grade and cutting conditions; it is not simply a mixture of carbon and tungsten.
Varieties and Uses: There are various grades of carbide tools designed for different machining operations, including finishing, medium, and roughing cuts. The choice of carbide type depends on the material being machined and the specific requirements of the task.
-Ceramic Tools
Benefits in High-Speed Machining: Ceramic tools excel in high-speed machining contexts where high temperatures are generated. They offer excellent wear resistance and can achieve higher cutting speeds than both HSS and carbide tools.
Limitations: However, ceramic tools are more brittle and require careful handling to avoid chipping or breaking during operation.
-Cermets
Properties: Made from ceramic particles bonded with metallic binder, offering a good balance of hardness and toughness.
Applications: Suitable for finishing and semi-finishing of steel and cast iron. Cermets provide superior finish quality and wear resistance.
-Diamond Cutting Tools
For Precision and Abrasive Non-Ferrous Materials: Diamond cutting tools can suit selected non-ferrous metals and abrasive nonmetals. Do not select diamond solely because a workpiece is hard; conventional diamond tooling is generally unsuitable for cutting steels.
Cost Considerations: Compare tool cost, usable life, and accepted-part quality for the application. Diamond is not automatically the most expensive or highest-performing option.
-Cubic Boron Nitride（CBN）
Properties:CBN (PCBN) is a material with a hardness second only to synthetic diamond
Applications: Ideal for cutting hard materials like hardened steels, cast irons, and superalloys. Commonly used in automotive and aerospace industries for precision work.
Types of operation for Lathe Cutting Tools
Lathe cutting tools can also be categorized based on the operations they are designed to perform. Each type of operation requires tools with specific shapes, angles, and properties to efficiently execute tasks while maintaining tool longevity and workpiece quality. Here are some common categories of lathe cutting tools based on the operations they perform:
-Turning Tools
Purpose: Used for the basic cutting and shaping of the workpiece.
Types: Includes roughing tools for bulk material removal and finishing tools for achieving a smooth surface finish.
-Facing Tools
Purpose: Specifically designed for cutting along the end face of the rotating workpiece, typically to create a flat surface.
Types: Similar to turning tools but typically have a different orientation to the workpiece.
-Boring Tools
Purpose: Used to enlarge holes or cylindrical cavities made in the workpiece.
Types: Boring bars and heads, which may vary in size and design based on the depth and diameter of the hole being machined.
-Threading Tools
Purpose: Designed to cut threads on the inside (internal threading) or outside (external threading) of a workpiece.
Types: Single-point threading tools and inserts cut internal or external threads on lathes. Taps and dies are other options; thread milling requires suitable driven tooling and machine-axis capability.
-Parting and Grooving Tools
Purpose: Used to cut a part off from the rest of the workpiece or to create grooves.
Types: Thin, sharp blades for parting and wider blades for grooving, often made from materials like HSS or carbide for durability.
-Knurling Tools
Purpose: Employed to create a textured pattern on the surface of a workpiece for improved grip.
Types: Form knurling displaces material with rollers; cut knurling removes material. Form knurling is a forming operation rather than a cutting operation.
-Form Tools
Purpose: Used to create specific shapes in a single pass, often for decorative or functional features.
Types: Custom-made to the shape of the desired feature, requiring precise engineering and manufacturing.
Types of structural design for Lathe Cutting Tools
Lathe cutting tools can also be categorized based on their structural design, which influences their functionality and suitability for various machining operations. Here’s an overview of lathe cutting tools distinguished by their structural differences:
-Solid Tools
Structure: Made from a single piece of material, typically high-speed steel (HSS) or carbide.
Use: Commonly used for general turning, facing, and other standard lathe operations. Solid tools are durable and easy to sharpen.
-Brazed Tools
Structure: Consist of a cutting tip, usually carbide, brazed onto a steel shank.
Use: Offer the hardness of carbide at the cutting edge while maintaining the toughness of steel in the shank. They are cost-effective but can be difficult to re-sharpen once the cutting edge wears out.
-Indexable Tools
Structure: Feature a replaceable cutting insert, which can be rotated or replaced when one edge wears out. The body of the tool is usually made of steel.
Use: Extremely popular in industry due to their convenience and cost efficiency, as they allow for quick changes of the cutting edge without needing regrinding.
-Clamped Insert Tools
Structure: Similar to indexable tools but use a clamp mechanism to secure the cutting insert.
Use: Provide a secure hold for the insert, making them suitable for heavy-duty operations and reducing the risk of insert movement under high cutting forces.
-Multi-Point Tools
Structure: Some tools provide several indexable edges used one at a time; other specialised tools engage multiple edges. These are different arrangements.
Use: Select the actual cutting arrangement for the operation. Multiple available edges do not mean that all edges cut simultaneously or improve every threading or grooving process.
-Tipped Tools
Structure: Have a small tip of a hard material, such as diamond or cubic boron nitride (CBN), attached to the tip of the tool.
Use: Ideal for precision cutting of hard or abrasive materials where extreme hardness and wear resistance are required.
Types of Feed Direction for Lathe Cutting Tools
-Right-Hand Tools
Feed Direction: In the conventional front-mounted external-turning arrangement, a right-hand tool cuts from right to left.
Usage: With the headstock on the left, this commonly means feeding towards the chuck. Confirm holder orientation, spindle direction, clearance, and the tool supplier’s permitted cutting directions.
-Left-Hand Tools
Feed Direction: In the conventional front-mounted external-turning arrangement, a left-hand tool cuts from left to right.
Usage: With the headstock on the left, this commonly means feeding away from the chuck. Actual CNC turret and tool arrangements must be checked against the holder and machine instructions.
-Neutral Tools
Feed Direction: A neutral designation does not by itself permit cutting in every direction; the insert and holder geometry determine the permitted feeds.
Usage: Neutral tools may suit particular turning, parting, or grooving operations. Confirm whether side turning is allowed instead of assuming a plunge-cutting tool can cut laterally.
Feed Direction: Check the permitted axial and radial movements for the selected neutral tool before programming the cut.
Usage: Check side clearance, insert support, and the manufacturer’s limits when changing feed direction. Neutral hand alone is not a guarantee of bidirectional capability.
Considerations for Feed Direction in Tool Selection
- Surface Finish and Geometry: The direction of the cut can affect the surface finish and the dimensional accuracy of the workpiece.
- Chip Evacuation: Proper tool orientation helps in effective chip evacuation, which is crucial for maintaining tool life and workpiece quality.
- Tool Wear: The direction of feed can influence how forces are distributed on the tool’s cutting edge, affecting wear patterns and tool life.
Please Note: There are many different lathe cutting tools for various uses. It’s best to talk to a CNC machinist or contact Sundi Tools to find the right one.
How To Select The Right Lathe Cutting Tool?
Selecting the appropriate lathe cutting tools involves several key factors to ensure efficient, accurate, and cost-effective machining. Here’s a straightforward guide to help you make the right choice:
Understand the Material of the Workpiece:
- Different workpiece materials require suitable tool grades and geometries. HSS and carbide can each suit a range of materials; stainless steel is not uniformly hard, and tool choice cannot be reduced to HSS for aluminium and carbide for stainless steel.
Determine the Machining Operation:
- Identify the specific operation you need to perform, such as turning, facing, threading, or grooving. Each operation may require a different tool geometry and type.
Choose the Right Tool Material:
- Common materials for lathe tools include:
- HSS: Versatile and often economical for suitable cutting conditions; precision is not limited to a low or medium level by HSS alone.
- Carbide: Available in many grades for productive machining; material compatibility and achievable precision depend on the complete tool and process.
- Ceramic: Useful in selected high-speed applications, with grade-dependent material and interruption limits.
- CBN and Diamond: These have different applications. CBN can suit hardened ferrous materials, while diamond commonly suits non-ferrous and abrasive nonmetallic materials; they are not interchangeable choices for every hard workpiece.
- Common materials for lathe tools include:
Consider Tool Geometry:
- Tool geometry affects the machining process and finish. Key aspects include the cutting angle, rake angle, and relief angle, tailored to the type of operation and material hardness.
Factor in Speed and Feed Rates:
- Ensure the chosen tool can handle the feed rates and speeds required for your specific operations. This compatibility influences tool wear and quality of finish.
Machine Compatibility:
- Check that the tool can be properly mounted and accommodated by your lathe. Compatibility includes shank size, tool post, and clearance.
Look at Coatings:
- Coated tools, such as those with Titanium Nitride (TiN), can offer increased durability and performance, particularly in challenging conditions.
Consult Experts:
- When in doubt, seek advice from experienced machinists or technical representatives from tool manufacturers. They can provide valuable insights based on your specific machining requirements.
By carefully considering these factors, you can effectively select lathe cutting tools that will perform well with your materials and machining processes, ultimately improving productivity and product quality.