Cutting tools are the unsung heroes of manufacturing, construction, and countless other industries. They shape our world, literally and figuratively, by removing material to create the objects we use every day. But what is a cutting tool actually called? The answer, surprisingly, isn’t always straightforward. The specific name depends on the tool’s design, function, and the material it’s designed to cut. This article delves into the fascinating world of cutting tool terminology, exploring the diverse names and purposes behind these essential implements.
Understanding the Broad Categories of Cutting Tools
At the highest level, cutting tools can be broadly categorized based on their primary function and the material they’re intended to work with. This categorization helps to establish a common understanding before diving into more specific tool names.
Machining Tools
These tools are primarily used in machining processes, where material is removed from a workpiece to create a desired shape. Machining tools are often used in conjunction with machine tools like lathes, mills, and drills.
Examples include drill bits, milling cutters, turning tools, and broaches. The key characteristic of machining tools is their precision and ability to create complex geometries. They are often made from high-speed steel (HSS), carbide, or other hard materials to withstand the high temperatures and stresses involved in machining.
Abrasive Cutting Tools
Abrasive cutting tools remove material through a grinding or abrasive action. Instead of a sharp, defined cutting edge, these tools utilize small, hard particles to wear away the workpiece.
Grinding wheels, abrasive saws, and honing stones fall under this category. Abrasive cutting is often used for finishing operations, creating smooth surfaces, and cutting hard or brittle materials. The abrasive particles can be made from materials like aluminum oxide, silicon carbide, or diamond.
Hand Tools
Hand tools are powered by human force and are used for a wide range of cutting tasks. These tools are often more versatile than machine-specific tools and are essential for tasks that require precision or are difficult to automate.
Knives, saws, chisels, and shears are common examples. The design of hand tools is often optimized for ergonomics and ease of use. They are typically made from hardened steel to maintain their sharpness and durability.
Woodworking Tools
While some woodworking tools overlap with hand tools, this category encompasses tools specifically designed for shaping and cutting wood. Woodworking requires tools that can cleanly sever wood fibers and create smooth surfaces.
Saws, chisels, planes, and carving tools are essential for woodworking. The geometry and materials used in woodworking tools are often tailored to the specific properties of wood.
Delving into Specific Cutting Tool Names and Their Applications
Now that we’ve covered the broad categories, let’s explore some specific cutting tool names and their corresponding applications. Understanding these names and functions is crucial for anyone working in manufacturing, construction, or related fields.
Drill Bits: Creating Holes with Precision
Drill bits are rotary cutting tools used to create holes in various materials. The design of a drill bit is crucial for efficient chip removal and accurate hole sizing.
Different types of drill bits exist for specific applications, including:
- Twist Drills: The most common type, used for general-purpose drilling.
- Spade Drills: Used for drilling large-diameter holes.
- Step Drills: Used for drilling holes of varying diameters in a single operation.
- Hole Saws: Used for cutting large, circular holes.
The material of the drill bit is also important. High-speed steel (HSS) is a common choice for general-purpose drilling, while carbide drill bits are used for harder materials and higher speeds.
Milling Cutters: Shaping Complex Surfaces
Milling cutters are rotary cutting tools used in milling machines to remove material from a workpiece and create complex shapes.
Different types of milling cutters include:
- End Mills: Used for creating slots, pockets, and contours.
- Face Mills: Used for machining large, flat surfaces.
- Ball Nose End Mills: Used for creating curved surfaces and intricate details.
- Shell Mills: Large diameter milling cutters used for rapid material removal.
Milling cutters are available in a wide range of sizes and shapes, allowing for great flexibility in machining operations. The number of flutes (cutting edges) on a milling cutter affects the cutting speed and surface finish.
Turning Tools: Machining Cylindrical Shapes
Turning tools are used in lathes to remove material from a rotating workpiece, creating cylindrical shapes.
Common types of turning tools include:
- Roughing Tools: Used for rapid material removal.
- Finishing Tools: Used for creating smooth, accurate surfaces.
- Threading Tools: Used for cutting threads on cylindrical parts.
- Parting Tools: Used for separating a finished part from the stock material.
Turning tools are typically made from carbide or high-speed steel and are available in a variety of shapes and sizes. The angle of the cutting edge is crucial for achieving the desired surface finish and preventing chatter.
Saws: Dividing Materials with a Cutting Blade
Saws use a toothed blade to cut through materials. They come in a wide variety of designs, each optimized for a specific type of cutting.
- Hand Saws: Manually operated saws for general-purpose cutting.
- Circular Saws: Power saws with a rotating circular blade.
- Band Saws: Power saws with a continuous loop of toothed blade.
- Reciprocating Saws: Power saws with a back-and-forth motion.
- Jigsaws: Used for cutting curves and intricate shapes.
The type of saw blade used determines the material that can be cut and the quality of the cut. Blades are available in a variety of materials, including high-speed steel, carbide, and diamond.
Chisels: Shaping Material with Impact
Chisels are hand tools used to shape or remove material by striking the chisel with a hammer or mallet.
Different types of chisels include:
- Wood Chisels: Used for shaping and carving wood.
- Cold Chisels: Used for cutting metal.
- Mortise Chisels: Used for creating mortise joints in woodworking.
The angle and shape of the chisel’s cutting edge are crucial for achieving the desired result. Chisels are typically made from hardened steel to withstand the impact of repeated blows.
Broaches: Creating Precise Internal Shapes
Broaches are multi-toothed cutting tools used to create or enlarge holes and internal shapes. They are pushed or pulled through the workpiece, with each tooth progressively removing more material.
Broaching is a highly efficient method for creating complex internal shapes, such as keyways, splines, and gear teeth. Broaches are typically made from high-speed steel or carbide and are custom-designed for the specific shape being created.
Materials Used in Cutting Tools
The material of a cutting tool is just as important as its design. The material must be able to withstand the high temperatures, stresses, and abrasive forces involved in cutting.
Common cutting tool materials include:
- High-Speed Steel (HSS): A versatile and relatively inexpensive material commonly used for drill bits, milling cutters, and turning tools.
- Carbide: A very hard and wear-resistant material used for high-speed machining of hard materials.
- Ceramics: Extremely hard and heat-resistant materials used for cutting very hard materials at high speeds.
- Diamond: The hardest known material, used for cutting extremely hard or abrasive materials.
The choice of cutting tool material depends on the material being cut, the cutting speed, and the desired surface finish.
Beyond the Basics: Specialized Cutting Tools
Beyond the common cutting tools, there are many specialized tools designed for specific applications. These tools often have unique designs and functionalities.
Examples of specialized cutting tools include:
- Gear Cutters: Used for cutting gear teeth.
- Reamers: Used for enlarging and finishing holes to precise dimensions.
- Taps and Dies: Used for cutting internal and external threads, respectively.
- Honing Stones: Used for fine-tuning the surface finish of machined parts.
- Plasma Cutters: Use a high-velocity jet of ionized gas to cut through electrically conductive materials.
- Laser Cutters: Use a focused beam of light to cut through a variety of materials.
- Waterjet Cutters: Use a high-pressure jet of water, sometimes mixed with abrasive particles, to cut through a wide range of materials.
These specialized tools demonstrate the breadth and depth of the cutting tool industry.
The Future of Cutting Tool Technology
Cutting tool technology is constantly evolving, driven by the demand for increased efficiency, precision, and automation.
Emerging trends in cutting tool technology include:
- Advanced Materials: The development of new cutting tool materials with improved hardness, wear resistance, and heat resistance.
- Coating Technologies: The application of thin films to cutting tools to improve their performance and extend their lifespan.
- Smart Cutting Tools: Cutting tools equipped with sensors and microprocessors to monitor cutting conditions and optimize performance.
- Additive Manufacturing: The use of 3D printing to create complex cutting tool geometries.
- AI and Machine Learning: Integration of AI and machine learning algorithms to optimize cutting parameters and predict tool wear.
These advancements promise to revolutionize the way we manufacture and shape the world around us. The evolution of cutting tool technology will continue to drive innovation across various industries. Understanding the names and functions of these tools is crucial for staying ahead in this dynamic field.
What is the “cutting edge” of a cutting tool, and why is it so important?
The cutting edge is the active part of the tool that directly removes material from the workpiece. It is formed by the intersection of the rake face and the flank face of the tool. Its sharpness, geometry, and material properties are critical determinants of cutting performance, influencing factors such as the force required, the quality of the finish produced, and the overall tool life.
The cutting edge’s condition directly impacts the efficiency and effectiveness of machining operations. A sharp, well-maintained edge ensures clean cuts, reduces friction, and minimizes heat generation. Conversely, a dull or damaged cutting edge can lead to increased cutting forces, poor surface finish, and premature tool wear, ultimately affecting productivity and component quality.
What is “rake angle” and how does it affect the cutting process?
The rake angle is the angle of the rake face (the surface over which the chips flow) relative to a plane perpendicular to the cutting direction. A positive rake angle means the rake face slopes away from the cutting edge, while a negative rake angle means it slopes towards the cutting edge. The rake angle significantly influences the cutting force and the chip formation process.
A positive rake angle generally reduces cutting forces, allowing for smoother cutting and better surface finishes, especially when machining softer materials. However, it can also weaken the cutting edge. Negative rake angles, on the other hand, provide a stronger cutting edge and are suitable for machining harder, more abrasive materials, but they require higher cutting forces and may result in a poorer surface finish.
What is “flank wear” and why is it a concern in machining?
Flank wear refers to the gradual erosion of the flank face (the surface that rubs against the newly machined surface) of the cutting tool. This wear is primarily caused by friction and abrasion between the tool and the workpiece. As flank wear progresses, the cutting edge becomes duller, requiring increased cutting forces and generating more heat.
Excessive flank wear is a major concern because it negatively affects the precision and quality of the machined part. It leads to dimensional inaccuracies, poor surface finish, and increased power consumption. Furthermore, continued use of a tool with significant flank wear can result in catastrophic tool failure, potentially damaging the workpiece and the machine tool itself, leading to costly downtime.
What’s the difference between “tool life” and “tool wear?”
Tool wear describes the gradual deterioration and loss of material from the cutting tool during the machining process. It’s a continuous process that leads to changes in the tool’s geometry and performance. Various mechanisms contribute to tool wear, including abrasion, adhesion, diffusion, and chemical reactions.
Tool life, on the other hand, is a measure of the useful cutting time a tool can endure before it reaches a predetermined wear criterion, requiring replacement or reconditioning. It’s the period during which the tool performs acceptably, meeting specified performance standards for surface finish, dimensional accuracy, and cutting forces. Therefore, tool wear is the *process*, and tool life is the *measure* of how long that process can continue before impacting performance.
What is “chatter” in machining, and how is it related to cutting tool geometry?
Chatter is a self-excited vibration that occurs during machining, resulting in undesirable noise, poor surface finish, and reduced tool life. It is often caused by dynamic instability in the machining system, where vibrations are amplified and sustained due to the interaction between the cutting tool, the workpiece, and the machine tool structure.
Cutting tool geometry plays a significant role in chatter. Inappropriate rake angles, clearance angles, and tool nose radii can exacerbate vibrations. For example, large rake angles may reduce cutting forces but can also make the tool more susceptible to vibration. Optimizing tool geometry, along with adjusting cutting parameters and ensuring machine tool rigidity, can help mitigate chatter and improve machining stability.
What are “coatings” on cutting tools, and what benefits do they provide?
Coatings are thin, hard layers applied to the surface of cutting tools using various techniques, such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). These coatings are typically composed of materials like titanium nitride (TiN), titanium carbonitride (TiCN), aluminum oxide (Al2O3), or diamond-like carbon (DLC).
The primary benefits of coatings include increased hardness, improved wear resistance, reduced friction, and enhanced thermal stability. This leads to longer tool life, higher cutting speeds, improved surface finish, and the ability to machine difficult-to-cut materials. Coatings also act as a barrier against chemical reactions between the tool and the workpiece, further extending tool life and improving cutting performance.
What is “nose radius” and how does it impact surface finish and tool strength?
The nose radius is the rounded corner at the tip of the cutting tool where the side cutting edge and the end cutting edge meet. It’s a crucial geometric feature that significantly affects the surface finish of the machined part and the strength of the cutting edge.
A larger nose radius generally produces a better surface finish by smoothing out the cutting action and reducing the formation of sharp peaks and valleys on the workpiece surface. However, a larger nose radius also increases the cutting force and can make the tool more prone to chatter. Conversely, a smaller nose radius provides a stronger cutting edge, more suitable for interrupted cuts or machining harder materials, but it may result in a rougher surface finish.