Home Business Insights & Advice The role of circle-segment milling tools

The role of circle-segment milling tools

by Sarah Dunsby
2nd Aug 23 11:27 am

Circle segment milling tools have advanced the milling process. These tools are highly versatile and effective in milling complex part geometries with unmatched reach capabilities. Unlike conventional milling tools, the circle segment end mills offer precision and excellent surface finish with reduced cycle times. The role of circle segment milling tools is revolutionary in manufacturing CNC milled parts.

Why choose Circle Segment Milling tools?

1. Reduced cycle time

You can reduce cycle time to a significant level using circle segment milling tools. These tools have excellent stability, allowing high feed rates without compromising surface quality. Their versatility makes them usable for both roughing and finishing, excluding the need for changing tools. Circle segment tools are also compatible with adaptive toolpaths to improve speed and efficiency.

2. High reachability

Circle segment milling tools have the most extended part reachability making these best for milling machining parts. These tools can achieve higher depths of cut with an enhanced material removal rate. They come in barrel-shape, oval, taper, and lens-shape, allowing extensive reach capabilities and compatibility with complex part geometries. You can fulfill every design requirement be it spiral grooves, curved shapes, narrow channels, etc.

3. High-quality finishing

Circle segment end mills are efficient finishing tools. You can contour deep pockets or tall walls without needing to extend tool access. Unlike conventional end mills, these tools don’t leave machining marks on part surfaces due to lower cutting forces. The tool stability and reduced deflection also enhance surface quality. The surface quality achieved using circle segment tools is impeccable.

4. Advanced coolant delivery system

Most circle segment tools are equipped with an advanced coolant delivery system. It helps in effective heat dissipation to avoid tool wear. The part temperature is controlled to minimize heating effects such as thermal expansion and contraction. The coolant also works as a lubricant to reduce friction resulting in enhanced surface finish. Plus, The coolant delivery system allows high-speed machining and lowers the risk of heat buildup.

5. Material versatility

You can use circle segment tools for various materials, including ferrous and non-ferrous metals, composites, and heat-resistant alloys. The tools function smoothly without any impact on tool life or part quality. The tools’ ability to minimize deflection, reduce cutting forces, and dissipate heat efficiently allows CNC milling components of different materials.

Circle segment milling tools: Limitations and compatibility issues

Milling parts is a complex process; you can’t depend on a single type of tool for the whole process. Where circle segment milling tools offer multiple benefits, they also have some unavoidable limitations.

Design limitations

Circle segment tools have low cutting widths, which makes these tools unusable for part design with larger surface areas. Due to continuous tangential contact, these tools don’t work well when making 2D cuts or machining flat surfaces. The tools also come in limited sizes and configurations, requiring custom tooling for specific projects.

Software compatibility

Circle segment tools have curved geometry and require intricate programming to design tool paths for optimum results. The CAM software must support circle segment milling as the feature is only available in newer versions. It is recommended to simulate the process and develop multiple toolpath strategies before CNC milling parts.

Machine compatibility

Although circle segment tools work well on traditional dual-axis and triple-axis machines, they don’t yield optimal results. If you want to maximize efficiency, using a five-axis machine with circle segment tools is recommended. It allows cutting at different angles enabling multi-axis contouring and enhancing dimensional accuracy. Plus, you can achieve the best results with a shorter machining time.

Circle segment milling tools applications

The versatility and adaptability of circle segment milling tools allow their use for a wide array of applications. The tools are being used in the production of turbine blades, impellers, medical implants, and automotive components. Their applicability to a diverse range of industries, including aerospace, automotive, medical, etc, is a testament to their capabilities.

You can use circle segment tools to produce aircraft components with complex airfoil profiles or to make mold and dies for automobile components. These tools have become indispensable in modern manufacturing. The increasing use of circle segment tools in rapid prototyping and rapid manufacturing processes makes them even more valuable for manufacturers.


Circle segment tools allow you to take on complex manufacturing tasks with confidence. The precision and accuracy that comes with these tools are unattainable by conventional end mills. Using circle segment tools helps you achieve the best surface finish at a relatively lower cycle time. You can work with complex part designs with long reachability and multi-axis machining compatibility.

Although circle segment tools have limitations, their advantages are much more significant. If you understand their applications, you can utilize them better. The surface finish, dimensional accuracy, and product quality from circle segment tools are superior to standard milling tools.


Q1: What are the differences between Circle-segment Milling Tools and Standard Milling Tools?

Circle segment tools have barrel-shaped designs, whereas standard milling tools have flat-end designs. The barrel-shaped design attribute allows these tools to minimize tool deflection and cutting force impacts. Therefore, the surface finish obtained from circle-segment tools is better than standard tools.

Q2: Which type of materials can be machined using circle-segment milling tools?

Circle segment tools are compatible with a variety of materials, including ferrous and non-ferrous metals, composites, and heat-resistant alloys. The advanced coolant delivery system allows you to use circle-segment tools for various materials.

Q3: Can circle-segment tools be used in place of standard milling tools?

You can use circle-segment tools instead of standard milling tools; however, they’ve certain limitations that make them unusable for different applications. You cannot use circle segment tools for 2D operations or excess roughing because the results are usually not up to the mark.

Q4: Are circle-segment tools usable in standard three-axis CNC machines?

Yes, circle segment tools can be used in three-axis CNC machines. But using these tools in advanced five-axis machines to unleash their full potential is recommended. Three-axis machines operate at fixed 90-degree angles, whereas five-axis machines can operate at different angles.

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