Multi-Axis Finisher Q&A

What is a Multi-Axis Finisher?

A tool that uses an extremely large radius to increase finishing performance in two different ways, depending on the needs of the machinist. Either the Multi-Axis Finisher will provide a better surface finish than a traditional Ball End Mill in the same amount of time, or will provide the same surface finish in far less time than a traditional Ball End Mill. A middle ground with improved surface finish and reduced cycle time is also easily achievable.

What Are Other Names for Multi-Axis Finishers?

Multi-Axis Finishers are oftentimes referred to as Barrel Cutters or Conical Barrel Mills or Circle Segment Cutters, among many others.

What Are the Different Forms of Multi-Axis Finishers, and How Do They Differ?

There are several different forms of Multi-Axis Finishers, including Lens, Taper, Oval, and Barrel. With a Lens Form, there’s a large radius on the end of the tool that’s in line with the tool axis. Taper Form, in contrast, has three tangential radii and a large radius defined at a specific angle relative to the tool axis. An Oval Form has two tangential radii, offering additional angle flexibility, while a Barrel Form has a large radius on the OD of the tool.

The most significant benefit is oftentimes observed utilizing a Taper Form Multi-Axis Finisher, as the radius of this tool can become vastly large on this form, while the others are more limited. However, this great benefit also comes with the least amount of flexibility in terms of approach to a workpiece.

What Are the Benefits of a Multi-Axis Finisher?

There are two clear benefits to using a Multi-Axis Finisher, compared to a Ball End Mill: Increased surface finish, and reduced cycle time (Or most likely both, concurrently).

What is a Benefit Multiple?

Helical Solutions is the industry’s premier manufacturer of Multi-Axis Finishers, and the Benefit Multiple is a significant reason why. Helical specifies the theoretical benefit that can be seen with its Multi-Axis Finishers, providing machinists direct insight into the gains that can be realized with these tools.

Benefit Multiple refers to the Cusp Height, correlated directly with the theoretically-achievable surface finish. Assuming the same cusp height from a Ball End Mill to a Multi-Axis Finisher, the Benefit Multiple relates to the time savings that could be seen in a machinists’ toolpath. For example, a Benefit Multiple of 4 would result in a toolpath ¼ as long as for a Ball End Mill of the same diameter. The stepover pass-to-pass would be 400% as much as a Ball End Mill to keep the same cusp.

When Should I Not Use a Multi-Axis Finisher?

Multi-Axis Finishers are best applied to wide-open surface areas; or large, smooth contours rather than small features or tight areas. Application of these tools will always be on a case-by-case basis. For help with your specific application, contact Helical Solutions Technical Support at 866-543-5422.

How Can I Get the Most Out of My Multi-Axis Finisher?

Multi-Axis finishers are best utilized when working further towards the OD of the tool. Tapered Form Multi-Axis Finishers are the most obvious choice for this, as its nose radius is small and has the least amount of efficiency. Similarly to a ball end mill, working near the center will have limited cutting ability, while the OD of the tool will see the full surface footage of the programmed RPM.

Taper Form Multi-Axis Finishers should be used when tilted at the specified taper angle. Oval Form Multi-Axis Finishers should be used towards the OD. Lens Form Multi-Axis Finishers should be tilted to avoid working on-center.

Lens Form Multi-Axis Finishers Look Like a High Feed End Mill. Can I Use it That Way?


Yes. However, there are differences in the form, and while a Lens Form Multi-Axis Finisher could theoretically be used as a High Feed End Mill, the two tools are not interchangeable.  A High Feed End Mill would not be the best choice for Multi-Axis Finishing, nor would a Lens Form Multi-Axis Finisher be our first recommendation for feed milling.

Do I need special software to program Multi-Axis Finishers?

Yes. A number of years ago, there were only a few CAM software packages that supported the programming of these specific forms. Nowadays, most CAM software providers have some degree of support for this method. Two of the first CAM software offerings to support this were MasterCAM and Hypermill, though many additional options exist today.

Why haven’t I heard of Multi-Axis Finishers Until Now?

In the grand scheme of things, Multi-Axis Finishers provide a very new approach to finishing, having been developed within the last handful of years.  Similar to High Efficiency Milling, these tools offer a new technique to approach your workpiece, offering increased efficiency and reduced cycle times.  Compared to the history of milling, modern tool manufacturing and CAM software have only just become able to program these unique forms.  Multi-axis finishers are positioned to revolutionize the world of finishing.

For more information on Multi-Axis Finishers, visit Multi-Axis Finishers: The Key to Amazing Surface Finish.

Multi-Axis Finishers: The Key to Amazing Surface Finish

A Key to Improving Surface Finish

In today’s Manufacturing Industry, part finish and machining efficiency are key to a successful machine shop. It’s no surprise, therefore, that the popularity Multi-Axis Finishers has never been greater. Helical Solutions is a leader in the manufacturing of Multi-Axis Finishers, and its customers utilize this impressive tool when faced with extremely high surface finish requirements, oftentimes swapping out a traditional Ball End Mill to dramatically improve finish while minimizing cycle times.

Multi-Axis Finisher Basic Principles

A Multi-Axis Finisher can be easily recognized by its large radius included in the profile of the tool. With a larger radius, a far greater stepover can be used pass-to-pass while keeping the same cusp height as a Ball End Mill. This decreases the cycle time by a known value called the Benefit Multiple.

A Multi-Axis Finisher with a Benefit Multiple of 8 will reduce the cycle time to 1/8 of the cycle time for a Ball End Mill of the same shank diameter – an 87.5% time savings! If a Multi-Axis Finisher is used with the same pass-to-pass stepover as a Ball End Mill, the finish will be drastically improved due to exponentially smaller cusp heights. Most situations allow both reduced cycle time and improved surface finish to be achieved.

The images below show the comparison of a ball end mill to an Oval Shape Multi-Axis Finisher with a benefit multiple of 4.

Due to their large radii, Multi-Axis Finishers are best suited for wide open, flowing, and somewhat flat surfaces. Smaller spaces, especially tight corners, will generally not see as much benefit from these tools due to limited use of the major radius.

Multi-Axis Finisher Tool Selection

The Manufacturing Industry’s leader in Multi-Axis Finishers, Helical Solutions offers 3 distinct profiles, each fully stocked and available to ship the day of purchase.

Oval Form Multi-Axis Finishers

The oval form includes 2 tangential radii and offers the most versatility in smaller spaces where a slightly varied approach angle is required, such as impellers or fan blades.

Taper Form Multi-Axis Finishers

The taper form includes 3 tangential radii and a taper angle. It allows for the largest radius, and therefore greatest potential improvement of finish and reduction of cycle time. They are best used where a specific approach angle is needed and where maximum performance gain is desired.

Lens Form Multi-Axis Finishers

The lens form includes 2 tangential radii on the end of the tool and is used for work mostly on the face of a part. Tilt angles of approximately 5 degrees are recommended for these tools to avoid working on-center.

Programming Multi-Axis Finishers

Programming Multi-Axis Finishers requires some additional consideration compared to a typical end mill. Luckily, many modern CAM packages offer support for these unique profiles, including many of Helical’s CAM partners. Each software has their own name for these toolpaths, so reach out to your CAM or Helical sales rep to find how you can program yours!

For more information on Multi-Axis Finishers, and to learn if this advantageous tool is right for you, read our Multi-Axis Finishers Q&A.

Maximizing Tool Life with Helical’s Dplus Coating

Choosing the correct tool coating is extremely important when machining highly abrasive materials like composites, graphite, aluminum alloys, and other non-ferrous materials. Proper coating selection will result in maximized tool life and a higher quality final part. When searching for a coating, it is imperative to find one that has high hardness and maintains a sharp cutting edge, like Helical Solutions’ Dplus coating. This post will explore what Dplus coating is (and isn’t), and when it might help you gain a competitive edge at the spindle.

What is Helical Solutions’ Dplus Coating?

Helical’s Dplus is a premium coating, specially engineered to extend tool life when machining materials ranging from aerospace aluminums to graphite or abrasive composites. It has a Tetrahedral Amorphous Carbon (taC) bond structure, which delivers remarkable enhancements in tool life compared to traditional DLC coatings.

Helical’s Dplus coating is applied by a Physical Vapor Deposition (PVD) process. This method of coating takes place in a near-vacuum and distributes micron-thick layers evenly onto a properly prepared tool. Since this coating is applied via a PVD process, it is inherently different than true diamond created through Chemical Vapor Deposition (CVD) processes. While this means it can be outlasted by CVD diamond, Dplus is a thinner coating allowing it to have a sharper cutting edge.

For more information on the PVD coating process, read PVD Coating vs. CVD: Two Common Coating Application Methods.

When Should a Machinist Use Dplus Coating?

When Machining Highly Abrasive Materials

Dplus is an excellent choice when working in abrasive non-ferrous materials like graphite and high-silicon aluminums. It is an extremely hard coating (50 Gpa), which enables it to remain strong against abrasive materials. It also has a very low coefficient of friction, allowing for optimal lubricity. This reduces the risk of built-up edge and ensures chips can be easily evacuated out of the flute valleys.

In Production Runs

The combination of Dplus being an extremely hard and sharp coating, makes it a true winner when it comes to tool life. Using a Dplus coated tool in extended production runs can pay dividends at the spindle, especially when working in highly abrasive non-ferrous materials.  

Although Dplus takes the spot as Helical’s highest performing coating for non-ferrous materials, it may not be needed in certain applications. Its high hardness and abrasion resistance may be necessary for long production jobs, but may not be necessary for shorter jobs and one-off parts.

When Should a Machinist NOT Use Dplus Coating?

In High Temperature Applications

Although Dplus coating provides outstanding tool life and sharpness, it can’t be run at extremely high temperatures. This coating should not be run in any ferrous material or high temperature aerospace alloys.

Key Takeaways

Featuring an exceptionally low coefficient of friction and extremely high hardness, Helical’s Dplus coating maintains a sharp cutting edge, while still resisting abrasion, making it an excellent choice in low temperature applications of highly abrasive non-ferrous materials.

For more information on Helical Solutions’ coatings, visit https://www.helicaltool.com/resources/tool-coatings.

The Advantageous Qualities of Helical Solutions’ Nplus Coating

When it comes to machining difficult materials like high-silicon aluminums, abrasive copper alloys, and other non-ferrous and aluminum alloys, finding a coating that improves performance and increases tool life can be difficult. When machining in aluminum-based materials, machinists often opt for an uncoated tool due to the sharp cutting edge needed. Uncoated tools may give you the sharpest edge possible, but Helical’s Nplus coating helps combat wear and keep your edge sharp for longer, allowing you to win at the spindle and gain a competitive edge.  

What is Helical Solutions’ Nplus Coating?

Helical’s Nplus coating is applied by a Physical Vapor Deposition (PVD) process. This method of coating takes place in a near-vacuum and distributes micron-thick layers evenly onto a properly prepared tool.

For more information on the PVD coating process, read PVD Coating vs. CVD: Two Common Coating Application Methods.

Nplus is a premium coating, specially engineered to extend tool life when machining non-ferrous and aluminum alloys. 

nplus coating chart
The above image was taken from Helical Solutions’ Coating Chart.

When Should a Machinist Use Nplus Coating?

When Machining Non-ferrous and Aluminum Alloys

Helical’s Nplus coating is optimized for machining difficult aluminum alloys and other abrasive non-ferrous materials, as its composition doesn’t react with aluminum as some other coatings do. This coating possesses many advantageous qualities, including its high hardness (40 GPa), which provides excellent edge retention to ensure that your tool stays sharp for longer. Also, its high working temperatures (2,012°) and its thickness (1-4 µm) provide further wear resistance when tackling these difficult-to-machine materials.

Nplus coated Helical end mills

When Working in High Temperature Non-Ferrous Applications

When machining in many non-ferrous and aluminum alloys, high temperatures can become an issue. Nplus is specially designed to withstand temperatures up to 2,012°, allowing tooling to run at the high temperatures these abrasive materials require, without degrading them.

When Machining Large Production Runs

Machining materials like wrought aluminum, cast aluminum, graphite, and other non-ferrous alloys can quickly end the life of your tool, costing time and money. Nplus coating is specially engineered to extend tool life in these materials, allowing your tool to stay in the spindle for longer. This calls for less tool changes, creating a more efficient process flow in your large production runs.

Helical’s Nplus Coated Tooling

Helical’s 5 Flute End Mills for Aluminum

Introduced in Helical’s Spring 2022 Catalog, Helical’s 5 Flute End Mills for Aluminum are specially engineered for optimal performance in High Efficiency Milling (HEM) of aerospace aluminum alloys and other non-ferrous alloys. They’re offered in two unique styles, both fully stocked in Helical’s Nplus coating:

5 Flute – Corner Radius  – Variable Pitch – Chipbreaker Rougher

5 Flute – Corner Radius – Variable Pitch – End Mill

Helical’s Multi-Axis Finishers for Aluminum

Also introduced in Helical’s Spring 2022 catalog, this offering of Multi-Axis Finishers feature a specially defined profile for massive reductions in cycle times and vastly improved surface finish when machining aluminum.  They’re offered in 3 styles, all fully stocked in Helical’s Nplus coating to ensure excellent finish in abrasive aluminums and extended tool life in a wide variety of non-ferrous materials.

Multi-Axis Finishers – 3 Flute – Lens Form

Multi-Axis Finishers – 4 Flute – Taper Form

Multi-Axis Finishers – 4 Flute – Oval Form

For more information on Helical Solutions’ coatings, visit https://www.helicaltool.com/resources/tool-coatings.

Machining Nickel Alloys: Avoiding All-Too-Common Mishaps


Nickel-based alloys are growing in popularity across many industries such as aerospace, automotive, and energy generation due to their unique and valuable mechanical and chemical properties. Nickel alloys exhibit high yield and tensile strengths at low weights and have high corrosion resistance in acidic and high temperature environments. Because of these advantageous properties, nickel alloys have increasingly become popular in machine shops.

Unfortunately, nickel alloys have a reputation for creating issues at the spindle. These metals present themselves to be problematic as they easily work harden. Further, nickel alloys generate high temperatures during machining, and have gummy chips that can weld onto cutting tools, creating built-up edge (BUE). Fortunately, with the correct approach, one can be successful in cutting nickel alloys.

Work Hardening

Across machine shops, nickel alloys are notorious for being difficult to machine. This reputation stems, largely, from work hardening, or a metal’s microhardness increasing due to the addition of heat. According to the Nickel Development Institute, this heat is generated through friction and plastic deformation of the metal. As the metal is cut, the friction between the cutting tool and workpiece generates heat which is concentrated around the cutting area.

Simultaneously, the metal is being physically worked. This means that as it is being machined, it is experiencing plastic deformation, which is a physical property that measures how much a material can be deformed to the point that it cannot return to its original shape.

This physical working of a nickel alloy increases its hardness faster than it does most other metals. The combination of high heat generation and physical work quickly increases the alloy’s hardness, causing tools to dull quickly and fail. This may result in scrapped parts and broken tools.

8 flute HVNI End Mill for Machining Nickel Alloys
Shown above is Helical Solutions’ End Mill for Nickel Alloys. This tool, engineered to excel in Inconel 718 and other nickel-based superalloys, is fully stocked in 6 and 8 flute styles.

Tool Adhesion

As nickel alloys are being machined and heat is generated, chips tend to become stringy and weld themselves to a tool’s cutting edge. This phenomenon, built up edge or BUE, rounds the cutting edge of the tool, resulting in poor cuts and increased friction, thus further contributing to work hardening. An example of BUE is seen in the image below.

Zoomed in display of built-up edge on End Mill Flutes
On the above tool, chips from the workpiece (Inconel 718) have welded onto the cutting edge, severely decreasing the tool’s effectiveness. Image Source: International Journal of Extreme Manufacturing

Built-up edge also speeds up tool wear, as the rotational forces involved in the cut increase. Now that the cutting edge is rounded from welded chips, a blunt tool is being forced into the workpiece.

With a blunt edge, the cutting motion changes from a shearing action to plowing. In other words, instead of cutting through the metal, the tool is pushing the material, resulting in poor cuts and increased friction.

Excessive Heat Generation

With poor cutting, internal heat of the tool rises, which can cause thermal cracking, defined by cracks that form perpendicular to the cutting edge. The fractures within the tool are created by extreme internal tool temperature fluctuations.

As a cutting tool rapidly overheats while cutting nickel alloys, cracks may form which can lead to catastrophic tool failure. With high temperatures, galling may also occur, which is characterized by pieces of the tool flaking off due to the same adhesion that causes BUE. As the tool is being welded to the workpiece and the machine continues to rotate it, pieces of the tool may start to break off resulting in tool failure.

Overcoming Nickel Alloy Difficulties

Temperature Control and Coolant Usage

The first step to effectively machine nickel alloys is to keep temperatures manageable as the workpiece is cut. Using high pressure coolant is mandatory. Coolant pressure should be 1000 psi or greater. This high pressure concentrating on the cutting zone of the workpiece will dissipate heat within both the cutting tool and workpiece. By doing so, the chances of work hardening lessen.

High pressure coolant will also aid in clearing out chips from the cutting area. Those hot gummy chips are responsible for BUE. Removing them as quickly as possible reduces the risk of BUE forming on the cutting edge. Additionally, chip removal is important to avoid chip recutting.

Chips absorb much of the heat and often work harden themselves. Recutting these hardened chips will dull the cutting edge resulting in poor cuts and decrease tool life. In general, water-based cutting fluids are preferable as they have higher heat removal rates and have a lower viscosity, which is needed for high metal removal operations.

Using the Proper Techniques

To also assist with heat removal, utilize climb milling techniques, where possible. When climb milling, the chip thickness is at its maximum at the beginning of the cut and tapers off until the cut is complete. Due to this, less heat is generated, as the cutting tool does not rub on the workpiece. Most of the heat from the cut is transferred into the chip.

Selecting the Proper Tooling and Coating

The next step is selecting the right end mill. Your end mill of choice should have a proper tool coating, such as Helical’s Tplus coating. Tool coatings are specifically engineered to improve tool performance by reducing friction, increasing tool microhardness, and extending tool life.

Next is selecting flute count. Tools used for nickel alloys need to be rigid to withstand the cutting forces present when machining high hardness alloys. Therefore, higher flute counts are necessary. If using traditional roughing toolpaths, your end mill should have at least 6 flutes. With 6 flutes, there is sufficient flute valley depth to allow for chip evacuation, while having a larger core diameter keeps the tool strong and rigid.

For finishing operations and instances of implementing high efficiency milling, higher flute counts should be considered. A tool used this way should have 8 flutes to provide excellent surface finish.

Helical’s End Mills for Nickel Alloys

CNC tooling manufacturer Helical Solutions’ End Mills for Nickel Alloys product offering, its HVNI tool family, specializes in machining nickel alloys as it exhibits these key tool features.

Four Helical Solutions End Mills for Nickel Alloys positioned over a Helical product container
The tools shown above are Helical Solutions’ End Mills for Nickel Alloys. These tools are coated in Tplus for high hardness, resulting in improved tool life and increased strength,

With its Tplus coating and variable pitch to minimize chatter, these solid carbide end mills are engineered to perform in all grades of nickel alloys. Coupled with their geometry to maximize cutting performance, Helical’s End Mills for Nickel Alloys utilize faster speeds and feeds, which are readily available on the Helical Solutions website and Machining Advisor Pro.

For more information about the chemical make-up, uses, and categorization of nickel alloys, read “In the Loupe’s” post “Understanding Nickel Alloys: Popularity, Chemical Composition, & Classification”.

Understanding Nickel Alloys: Popularity, Chemical Composition, & Classification

What is Nickel Alloy?

Nickel-based alloys have been a cornerstone of manufacturing for decades, desirable for their broad range of varying resistances to heat, oxidation, and corrosion. Nickel alloys also have a high strength-to-weight ratio and superior electrical conductor abilities. Because of these mechanical and chemical properties, they are primarily used in aerospace, oil, electrical, and chemical industries.

Understanding this valuable metal and how to properly machine it is imperative to delivering an optimal final part.

cnc machining nickel alloys
Machining Nickel Alloys. Image source: IMS-Stainless.com

Nickel Alloy Chemical Composition and Classification

Nickel is commonly found in the form of an alloy, as its crystalline structure allows the element to be paired well with other metals. These atoms are arranged in a face centered cubic lattice; this structure is shown in figure 1 below.

Drawing that shows lattice structure of Nickel
Lattice structure of Nickel. Image source: PriyamStudyCentre.com

The Atomic Configuration of Nickel

According to Priyam Study Centre’s Learning Chemistry, an open face lattice has the highest atomic packing number (the number of atoms per unit volume) of any metallic lattice configuration, with an atom present at each of the 6 faces and 8 corners of the cube. This structure is largely responsible for nickel’s strength and ability to create strong metallic bonds to chromium, cobalt, iron, and molybdenum, the most common metals found in these alloys.

Categorization of Nickel Alloys

According to City Special Metals’ article on Machining Nickel and Nickel Alloys, nickel alloys are organized into five main categories: Groups A through E. These groups are determined through the percentage of nickel present, as well as the most prominent metal that the nickel is chemically bonded with.

Table 1 displays the breakdown of these groups, showing each group’s chemical composition and a few examples of common types of nickel alloys found in that category.

GroupPercentage of NickelPaired MetalsExamples
Group A95% and greaterAlmost pure nickelNickel 200, 201, 205, and 212
Group B29% to 42%CopperMonel 400, Invar 36
Group C70% to 75%Chromium and ironInconel 600, Monel K-500, and Nickel 270
Group D50% to 56%Chromium and ironInconel 718, Inconel 625, and Hastelloy C-22
Group E63%Copper and ironMonel R405 is the only Nickel alloy in this category
Table 1: Categories of nickel alloys and their chemical compositions. Table data source: Machining Nickel and Nickel Alloys: A Guide from CSM; Nickel Based Alloys: Everything You Need to Know.

Significance of Understanding Composition

Understanding your workpiece material is just as important as understanding your machinery and tools. According to Global Market Insights (GMI), the nickel alloy market has been growing over 4% each year since 2017, and this growth is seeing an upward trend. As these alloys increase in popularity and demand, knowing the chemical compositions and classification of your specific workpiece will play a key role in successfully machining it.

Fabricating products made of nickel alloys present common struggles in every machine shop. Learn how to select proper tooling and implement machining techniques to overcome these challenges by reading CNC Machining Nickel Alloys: Avoiding All-Too-Common Mishaps.

4 Key Benefits of Combination Feed & HEM End Mills

Designed to conquer machine limitations and other common machining issues, combination and multifunctional tooling are highly coveted by machinists. These tools often integrate multiple geometries and flute designs to tackle wider varieties of machining applications with the same tool. This means fewer tools and tool changes are needed within a job, reducing complexity and increasing shop flexibility.

Taking these Issues and limitations into consideration, Harvey Performance Company’s Engineering Team went to work to design a new series of end mills referred to as Helical Solutions’ Combination High Feed & HEM End mills. This product series offers a feature set that will solve the four common issues listed below along with a few other issues that machinists commonly experience in the spindle.

For most shops, machine limitations cause longer, costlier, and more complicated jobs. If you are reading this article, you may know exactly what we are talking about. Machinists have a job that needs to be completed and end up having to add another operation. They find themselves improvising on tooling to complete an operation. This is because their machine has a limited number of tool stations, less than adequate horsepower, or several other limitations. Many times, this will impact operations in a negative way by increasing overall cost or reducing the quality of parts. As the name suggests, Helical’s Combination Feed & HEM tooling has been designed to excel in both applications without requiring a tool change. The end profile is non-center cutting for high feed applications, while the offset chipbreaker OD geometry excels in high efficiency milling strategies.

Helical Solutions Combination Feed & HEM end mill

How This Tool Addresses Machine Limitations

A common issue present in a fair number of shops is a limited number of tool stations available. The Combination Feed & HEM products afford the ability to do multiple roughing and finishing operations with one tool, using only one tool position. This eliminates the need to try to blend tools or control multiple offsets in your machining operation.

A second machine limitation that may affect your tool choice is you machine horsepower. The high feed end geometry and the chipbreaker OD geometry are both designed to reduce the amount of power required. This opens up new opportunities within light duty and low horsepower machines, offering more flexibility to your shop.

Cut Down Part Cycle Times

In a shop, long cycle times negatively impact productivity and machine availability. As the manufacturing industry becomes more competitive and as jobs become more demanding, the need for reducing cycle times becomes even more important.

The Combination Feed & HEM End Mills allow the use of both High Feed and High Efficiency milling strategies that provide high metal removal rates in your operations.  Increased material removal rates lead directly to reduced cycle times, plus the versatility of these tools helps to avoid time-consuming tool changes.

Click Here to Watch Helical’s Combination Feed & HEM Mill Be Pushed to the Limits

Limiting Complexity and Increasing Ease of Use

With today’s machined parts growing in complexity, programming can become cumbersome with multiple machining strategies and many tools required.  Finding ways to reduce the complexity of programming can help an entire job run smoother through your shop.

These Combination Feed & HEM End Mills provide an increased ease of use. This gives you the ability to conquer multiple operations with one tool. This eliminates the need to program and set-up multiple tools, boosting productivity

Helical Solutions Combination Feed & HEM end mill laying over a product container

Cutting Down on Costs

Another common issue is the cost of purchasing tooling. The Combination Feed & HEM End Mills offer a feature set that allows the consolidation of tooling and operations. Reducing the number of different tools needed for your application can reduce the overall cost of your operations substantially.

Feed/HEM Product Capabilities and Application Areas

Helical’s Combination Feed & HEM End mills are designed to tackle a broad range of demanding operations in a wide variety of steel types. As these products were engineered to solve machine limitation issues, the end geometry excels across a variety of operations. These include High-Feed milling operations, machining bores, closed or open pockets, internal or external contours, etc. The peripheral geometry was engineered with flexibility in mind. This allows the use of an HEM (High Efficiency Machining) toolpath to achieve high metal removal rates while maintaining great chip control as well as most traditional roughing and finishing strategies.

Helical Solutions Combination Feed & HEM end mill laying over a product container

The versatility of these tools can be easily illustrated with a long list of applications:

  1. High efficiency milling
  2. High feed slotting
  3. High feed roughing
  4. Milling in open and closed pockets
  5. Internal and external profiling
  6. Helical ramping and interpolation
  7. Rough and finish profile milling
  8. Offset plunge milling in slots and deep pockets
  9. Traditional roughing operations
  10. Contouring and profiling operations

Commonly, machinists would need a range of specialty tooling to complete different aspects of a job. This requires long cycle times, and higher costs when all the necessary tools are considered. As most shops suffer from a limited number of available tool stations, combination mills aid in alleviating this pressure. These tools are designed to excel and conquer.

Conquer Machine Limitations and Shop Issues

Helical’s Combination Feed & HEM End Mills were designed with versatility in mind. The major benefit of these tools is addressing machine limitations and the common issues presented above. These tools will provide you with a feature set that will allow you to combine operations, reduce cycle times, reduce cost, reduce scrap, and expand your machines capabilities. Let Helical impress you with the Combination Feed & HEM line of end mills.

The Secret Mechanics of High Feed End Mills

A High Feed End Mill is a type of High-Efficiency Milling (HEM) tool with a specialized end profile that allows the tool to utilize chip thinning to have dramatically increased feed rates. These tools are meant to operate with an extremely low axial depth so that the cutting action takes place along the curved edge of the bottom profile. This allows for a few different phenomena to occur:

  • The low lead angle causes most of the cutting force to be transferred axially back into the spindle. This amounts to less deflection, as there is much less radial force pushing the cutter off its center axis.
  • The extended curved profile of the bottom edge causes a chip thinning effect that allows for aggressive feed rates.

The Low Lead Angle of a High Feed End Mill

As seen in Figure 1 below, when a High Feed End Mill is properly engaged in a workpiece, the low lead angle, combined with a low axial depth of cut, transfers the majority of the cutting force upward along the center axis of the tool. A low amount of radial force allows for longer reaches to be employed without the adverse effects of chatter, which will lead to tool failure. This is beneficial for applications that require a low amount of radial force, such as machining thin walls or contouring deep pockets.

high feed mill roughing
Figure 1: Isometric view of a feed mill engaged in a straight roughing pass (left), A snapshot front-facing view of this cut (right)

Feed Mills Have Aggressive Feed Rates

Figure 1 also depicts an instantaneous snapshot of the chip being formed when engaged in a proper roughing tool path. Notice how the chip (marked by diagonal lines) thins as it approaches the center axis of the tool. This is due to the curved geometry of the bottom edge. Because of this chip thinning phenomenon, the feed of the tool must be increased so that the tool is actively engaged in cutting and does not rub against the workpiece. Rubbing will increase friction, which in turn raises the level of heat around the cutting zone and causes premature tool wear. Because this tool requires an increased chip load to maintain a viable cutting edge, the tool has been given the name “High Feed Mill.”

high feed end mill ad

Other Phenomena Due to Curved Geometry of Bottom Edge

The curved geometry of the bottom edge also sanctions for the following actions to occur:

  • A programmable radius being added to a CAM tool path
  • Scallops forming during facing operations
  • Different-shaped chips created during slotting applications, compared to HEM roughing

Programmable Radius

Helical Solutions’ High Feed End Mills has a double radius bottom edge design. Because of this, the exact profile cannot be easily programmed by some CAM software. Therefore, a theoretical radius is used to allow for easy integration.  Simply program a bullnose tool path and use the theoretical radius (seen below in Figure 2) from the dimensions table as the corner radius.

high feed mill programmable radius
Figure 2: Programmable radius of a double radius profile tool

Managing Scallops

A scallop is a cusp of material left behind by cutting tools with curved profiles. Three major factors that determine the height and width of scallops are:

  1. Axial Depth of Cut
  2. Radial Depth of Cut
  3. Curvature of Bottom Edge or Lead Angle

Figure 3 below is a depiction of the scallop profile of a typical roughing cut with a 65% radial step over and 4% axial depth of cut. The shaded region represents the scallop that is left behind after 2 roughing passes and runs parallel to the tool path.

roughing cut scallop profile
Figure 3: Back view of roughing cut with a 65% radial step over

Figures 4 and 5 show the effects of radial and axial depth of cuts on the height and width of scallops. These figures should be viewed in the context of Figure 3. Percentage by diameter is used rather than standard units of measurement to show that this effect can be predicted at any tool size. Figure 4 shows that a scallop begins to form when the tool is programmed to have a radial step over between 35% and 40%. The height increases exponentially until it is maximized at the axial depth of cut. Figure 5 shows that there is a linear relationship between the radial step over and scallop width. No relationship is seen between scallop width and axial depth of cut as long as ADOC and the radius of curvature of the bottom cutting edge remains consistent.

graph of scallop height versus depth of cut
Figure 4: Graph of Scallop Height vs. Depth of Cut
graph of scallop width versus depth of cut
Figure 5: Scallop Width vs. Depth of Cut

From the graphs in Figures 4 and 5 we get the following equations for scallop dimensions.

Notes regarding these equations:

  • These equations are only applicable for Helical Solutions High Feed End Mills
  • These equations are approximations
  • Scallop height equation is inaccurate after the axial depth of cut is reached
  • RDOC is in terms of diameter percentage (.55 x Diameter, .65 x Diameter, etc…)

Shop Helical Solutions’ Fully Stock Selection of High Feed End Mills

Curvature of the Bottom Edge of High Feed End Mills

The smaller the radius of curvature, the larger the height of the scallop. For example, the large partial radius of the Helical Solutions High Feed End Mill bottom cutting edge will leave a smaller scallop when compared to a ball end mill programmed with the same tool path. Figure 6 shows a side by side comparison of a ball end mill and high feed mill with the same radial and axial depth of cut. The scallop width and height are noticeably greater for the ball end mill because it has a smaller radius of curvature.

feed mill versus ball end mill
Figure 6: Scallop diagram of High Feed Mill and Ball End Mill with the same workpiece engagement

Full Slotting

When slotting, the feed rate should be greatly reduced relative to roughing as a greater portion of the bottom cutting edge is engaged. As shown in Figure 7, the axial step down does not equate to the axial engagement. Once engaged in a full slot, the chip becomes a complex shape. When viewing the chip from the side, you can see that the tool is not cutting the entirety of the axial engagement at one point in time. The chip follows the contour on the slot cut in the form of the bottom edge of the tool. Because of this phenomenon, the chip dips down to the lowest point of the slot and then back up to the highest point of axial engagement along the side. This creates a long thin chip that can clog up the small flute valleys of the tool, leading to premature tool failure. This can be solved by decreasing the feed rate and increasing the amount of coolant used in the operation.

high feed mill chip formation
Figure 7: Formation of a chip when a feed mill is engaged in a full slotting operation.

In summary, the curved profile of the bottom edge of the tool allows for higher feed rates when high feed milling, because of the chipping thinning effect it creates with its low lead angle. This low lead angle also distributes cutting forces axially rather than radially, reducing the amount of chatter that a normal end mill might experience under the same conditions. Machinists must be careful though as the curved bottom edge also allows for the formation of scallops, requires a programmable radius when using some CAM packages, and make slotting not nearly as productive as roughing operations.

Titanium Machining Cost Savings With Helical Solutions

When the manufacturing team at Geospace Technologies was looking for better tool life and improved performance on a Titanium CNC milling job, they turned to Harvey Performance Company and local Application Engineer Mike Kanigowski to dial in some Helical Solutions End Mills. With Mike’s help, Geospace Technologies, led by Lead Mill Programmer Tranquilino Sosa, achieved massive success and extensive titanium machining cost savings, which led them to completely shift their tooling repertoire to Helical’s high-performance end mills in their shop.

Struggling With Tool Life

Prior to switching to Helical, Geospace Technologies was experiencing trouble with tool life on a job that required both roughing and finishing toolpaths on a Titanium (Ti-6AL-4V) part. For their roughing pass, Geospace was using a competitor’s 4 flute, 3/8” diameter end mill with a 30° helix angle and TiALN coating. In traditional roughing toolpaths, this tool was running at 1,750 RPM with a 10 IPM feed rate. The tool would take four step downs, three with an axial depth of cut of .200”, and a final pass at .100” for a total depth of .700”.

When finishing, the team used a 1/2” version of the same competitor tool, running at 900 RPM with an 8 IPM feed rate. This would take two passes, one at .400” deep and the last down to the bottom of the part at .700”.

geospace technologies fadal VMC 4020 in a machining facility

With this strategy and tooling, the team was creating high-quality parts at a cycle time of 15 minutes and 22 seconds per part, but were only seeing the roughing tool last for 60 parts on average, and the finishing tool for around 120 parts. This was causing tool costs to be higher than they would like, and costing the team precious time with frequent tool changes.

Sosa had seen some of the success that other shops were having with Titanium milling using Helical Solutions end mills, and so they reached out to Kanigowski to see how Helical could help them lower their cost per part while achieving an even better finish.

Helical solutions HVTI-6 end mill Ad

Dialing in Tool Selection

When Mike got in touch with the team at Geospace, he knew there were some immediate benefits to changing the toolpaths used in this job. Using their ESPRIT software, the team was able to dial in a new program using high efficiency milling (HEM) toolpaths through ESPRIT’s “Profit Milling” technology.

With HEM toolpaths in place, Geospace was going to need new high performance tools to take full advantage of the programming adjustments. After much testing and evaluating several options from Helical’s extensive line of end mills for Titanium, Geospace settled on two solid tools.

Helical offers many different options for Titanium milling in HEM toolpaths. During testing, the team at Geospace decided on Helical EDP 59424, a 3/8” diameter, 7 flute, corner radius end mill. This tool features variable pitch geometry and offset chipbreakers for optimal chip evacuation, reduced harmonics, and minimized tool pressure, as well as Helical’s Aplus coating for high temperature resistance, decreased wear, and improved tool life.

7 flute chipbreaker tools lined up one by one
7 Flute Chipbeaker Tools Fresh Off the Grinder

When looking at the finishing toolpath, Geospace decided on Helical EDP 82566, a 3/8”, 6 flute, square end mill from Helical’s well known HEV-6 product line. This tool featured a variable pitch design to help mitigate chatter and leave a superior finish. While Helical also offers several tools for finishing toolpaths in Titanium, during testing this tool provided Geospace with the best finish for their specific part geometry.

Achieve Impressive Efficiency in Titanium Machining Operations With Helical Solutions’ HVTI-6 Cutter

Experiencing the “Helical Difference”

With the new tools in place, Sosa’s team reached out to Helical for help dialing in speeds and feeds. The Helical tech team was able to get them set up on Machining Advisor Pro, an advanced speeds and feeds calculator developed by the experts behind Helical Solutions tooling. With this “miracle worker” application in their arsenal, the team was able to easily dial in their new tools for their specific material grade, depth of cut, and machine setup.  

The team saw immediate positive results and cost-savings on this job. They were able to increase their roughing toolpaths to 4,500 RPM and 157 IPM. The finishing path remained largely the same, but resulted in a much improved final part. In total, cycle time dropped from 15 minutes and 22 seconds per part to 12 minutes and 17 seconds per part, which was great, but the improvement in tool life was where Sosa was most impressed.

Geospace technologies employee inspecting titanium end mills in a facility

With the new Helical end mill in the shop, Geospace was able to run both tools for 580 parts with very minimal wear on the tool. This was a nearly 1000% improvement in tool life for their roughing passes and a 483% improvement in tool life for the finishing operation. In total, one roughing tool was able to last more than 42 hours in the cut before needing to be replaced.

Eliminating the need for a tool change every 60 parts was also a significant time-saver. Constant tool changes were causing serious machine downtime, which was eliminated with the longer tool life experienced with the Helical end mills. What seems like a minor inconvenience will truly add up to dozens of hours in saved time over the course of a few months for Sosa’s team.

zoomed in image of titanium machining tool wear on a 7 flute chipbreaker
A Closeup of the 7 Flute Chipbreaker After 42 Hours In The Cut

Geospace was thrilled with the results they saw on this Titanium job, as they had never experienced long tool life in Titanium with any other competitor brand. Sosa and his team are excited to continue using Helical Solutions product across all of their other jobs going forward and to continue working with Kanigowski and the Helical tech team on dialing in tool selection and speeds and feeds on future projects.

Please see below for a head-to-head breakdown of the Helical end mills’ performance in terms of total costs and productivity gained versus that of the competitor. These numbers are measured per 1,000 parts, taking into account tooling costs, tool change time, labor costs, running parameters, and cycle times.


titanium machining cost savings chart

Chipbreaker Tooling: Not Just for Roughing

When many people think about solid carbide tools with chip breakers, they are usually tooling up for a roughing application. While the chipbreaker tool is a great choice for such applications, it can be utilized in a number of other areas too. In this post, we’ll examine many other benefits of the chip breaker style of tooling.

High Efficiency Milling (HEM)

High Efficiency Milling (HEM) uses CAM software to program advanced toolpaths that reduce cutting forces. These tool paths employ smaller end mills with a higher number of flutes (for a stronger core) running at higher speeds and feeds. This strategy includes a light radial depth of cut (RDOC), high axial depth of cut (ADOC), and a controlled angle of engagement.

Helical’s chipbreaking tools include serrated indents along the edge of flute for the entire length of cut. Because HEM utilizes heavy axial depths of cuts, these tools are able to break long chips into smaller ones. In addition to improving chip control and reducing cutting resistance, chipbreaker tools also help in decreasing heat load within the chips. This delays tool wear along the cutting edge and improves cutting performance. 

chipbreaker in spindle

Check out this testimony from a Helical Solutions customer:

“We were able to get going with the 7 flute tools with the chipbreaker. I have to say the difference was INCREDIBLE! We can now rough the entire part with one tool. Also, the operator doesn’t have to open the door to clear chips hardly at all. We were able to rough and finish a 4.15 dia. bore 2 inches deep through the part without having to clear chips at all. Before we had to clear the chips out at least 15-20 times. Many thanks for your support.”

Explore Helical Solutions’ Chipbreaker Roughers Today

Slotting

When slotting, a major concern is chip control. A large buildup of chips can cause the recutting of chips, which adds a lot of heat back into the tool. Chip buildup can also cause a heavy amount of chattering. Both of these conditions are detrimental to tool life. A chip breaking tool can help reduce chip build-up when slotting which will extend tool life. Remember when slotting that 4 flute tools should be utilized in steel. For aluminum and other non- ferrous materials, a 3 flute tool is best.

3 flute chipbreaker
Helical Solutions 3-Flute Chipbreakers

Trochoidal Slotting

Trochoidal slotting is a form of slotting that uses HEM techniques to form a slot. Trochoidal milling implements a series of circular cuts to create a slot wider than the cutting tool’s cutting diameter. Using the logic listed in the earlier paragraphs of this article, a chipbreaker should be used when performing this operation.

Advantages of Trochoidal Slotting:

Decreased cutting forces

Reduced heat

Greater machining accuracy

Improved tool life

Faster cycle times

One tool for multiple slot sizes

chipbreaker rougher ad

Finishing

A little known fact about Helical’s chipbreaker style tool is that the chip breakers are offset flute to flute, which allows for a quality finish on the walls of the part. When utilizing light depths of cuts, high-quality finishes can be achieved.