What to Know About Harvey Tool’s TiB2 Coating

Aluminum and magnesium alloys are common materials found in machine shops worldwide, and are known as an “easier” material to machine. However, machinists can still experience hiccups while machining this material if they are not prepared with the proper tooling.. When working with aluminum and magnesium alloys, it is important to choose a coating that will work to extend your tool’s life and aid in the removal of chips. A popular choice for this material bucket is Harvey Tool’s TiB2 coating.

What is Harvey Tool’s TiB2 Coating?

Harvey Tool’s TiB2 coating is a Titanium Diboride, ceramic-based coating that provides superb erosion resistance during machining. TiB2 is added to a tool by a method called Physical Vapor Deposition (PVD), which is conducted in a vacuum where particles are vaporized and applied onto a surface, forming thin layers of material onto the properly-prepped tool. This method enables the coating to be corrosion and tarnish resistant.

TiB2 Specifications

TiB2 is identified in Harvey Tool’s product catalog with a “-C8” following the sku number. It can be found offered in Harvey Tool’s lines of Variable Helix End Mills for Aluminum Alloys, Double Angle Shank Cutters, and Miniature High Performance Drills for Aluminum Alloys.

When Should a Machinist Use TiB2?

Chip Evacuation Concerns

TiB2 has an extremely low affinity to aluminum, which helps with the chip evacuation process. Simply, chips of a material are able to evacuate through chip valleys easier if they don’t have a high affinity to the coating being used. TiB2 coating does not chemically react with aluminum and magnesium, which allows for smoother chip evacuation, as the chips do not stick to the coating and create issues such as chip packing. This is a common machining mishap that can cause both part and tool damage, quickly derailing a machining operation. By using a coating that increases the lubricity of the tool, chips will not have a surface to stick to and will more smoothly evacuate from the flutes of the tool.

Large Production Runs

While an uncoated tool may work fine in some applications, not all applications can succeed without a tool coating. When working with large production runs where the tools need to hold up through the process of machining large numbers of parts, using a coating is always recommended because they extend the life of your tool.

When is TiB2 Coating Not Beneficial to My Application?

Extremely Abrasive Materials

During the PVD coating process, tools can reach a temperature in excess of 500° F, which can cause the toughness of the carbide to drop slightly. This process does not normally compromise the performance of the tool due to the coating being placed over the carbide. The coating then protects the slightly weakened edge and increases tool performance in recommended materials. Micro-fractures only start appearing when the tool is being run incredibly fast through highly abrasive materials, leading to a decrease in the life of the tool.

Extremely Soft Materials

The coating, while only a few microns thick at most, still provides an ever-so-slight rounded edge to the cutting edge of the tools it is placed on. It is important to take this into consideration, as using the sharpest tools possible when working with materials such as soft plastics is recommended. The sharpest edge possible decreases the likelihood of any “pushing” that might occur on the material and increases the likelihood of proper “shearing” when machining.

When Finish Is Vital

If your part’s finish is imperative to the final product, an uncoated tool may work better for your application. A coating, like stated above, creates a microscopic rounded surface to the cutting edge of the tool. When running tools at finishing speeds and feeds in materials like aluminum, a sharp edge can create the difference between a finished part that does – or does not – pass final inspection.

Chipbreakers vs. Knuckle Rougher End Mills

Knuckle Roughers and Chipbreakers are common profiles found on roughing end mills that, while fairly similar in appearance, actually serve different functions. Chipbreakers refer to the notches along the cutting edge of a tool that work to break up chips to prevent common evacuation mishaps. Knuckle Roughers refer to the serrated cutting edge of a tool, which works to enhance cutting action for an overall smoother operation.

Determining the appropriate style of tool is a very important first step to a successful roughing application.

Understanding the Two Styles

Chipbreaker End Mills

To aid chip evacuation, Chipbreaker End Mills feature a notched profile along the cutting edge that break down long chips into smaller, more manageable pieces. These tools are often utilized in aluminum jobs, as long, stringy chips are common with that material.

Each notch is offset flute-to-flute to enhance the surface finish on the part. This works by ensuring that as each flute rotates and impacts a part, following flutes work to clean up any marks or extra material that was left behind by the first pass. This leaves a semi-finished surface on your part.

In addition to improving chip control and reducing cutting resistance, these tools also help in decreasing heat load within the chips. This delays tool wear along the cutting edge and improves cutting performance. Not only are these tools great for hogging out a great deal of material, but they can be utilized in a wide array of jobs – from aluminum to steels. Further, a machinist can take full advantage of the unique benefits this tool possesses by utilizing High Efficiency Milling toolpaths, meant to promote efficiency and boost tool life.

Knuckle Roughers

Knuckle Rougher End Mills have a serrated cutting edge that generates significantly smaller chips than a standard end mill cutting edge. This allows for smoother machining and a more efficient metal removal process, similar to Chipbreaker End Mills. However, the serrations chop the chips down to much finer sizes, which allows more chips into the flutes during the evacuation process without any packing occurring.

Designed for steels, Knuckle Rougher End Mills are built to withstand harder materials and feature a large core. Because of this, these tools are great for roughing out a lot of material. However, due to the profile on the cutting edge, tracks along the wall can sometimes be left on a part. If finish is a concern, be sure to come in with a finishing tool after the roughing operation. Knuckle Roughers have proven the ability to run at higher chip loads, compared to similar end mills, which makes this a highly desired style for roughing. Further, this style of rougher causes a lot of heat and friction within the chips, so it’s important to run flood coolant when running this tool.

Key Differences Between Knuckle Roughers & Chipbreakers

While the two geometries offer similar benefits, it’s important to understand the distinct differences between them. Chipbreakers feature offset notches, which help to leave an acceptable finish on the walls of a part. Simply, the material left on an initial flute pass is removed by subsequent passes. A Knuckle Rougher does not feature this offset geometry, which can leave track marks on your part. Where part finish is of upmost importance, utilize a Knuckle Rougher to first hog out a great deal of steel, and work a final pass with a Finishing End Mill.

A unique benefit of Knuckle Roughers is the grind they possess – a cylindrical grind, compared to a relieved grind of a Chipbreaker End Mill. Because of this, Knuckle Roughers are easier to resharpen. Therefore, instead of buying a new tool, resharpening this profile is often a cheaper alternative.

How Material Specific Tooling Pays Off

A machinist is faced with many questions while selecting the proper tool for their job. One key decision that must be made is whether a material specific tool is appropriate and necessary for the application that’s going to be performed – whether the benefits of using this type of tool outweigh the higher price tag than that of a tool designed for use in a variety of materials. There are four main categories to consider when deciding whether a material specific tool is your best bet: internal tool geometry, coatings, material removal rates (MRR), and cost.

When to Utilize Material Specific Tooling

Are you a machinist in a shop that deals primarily with one type of material? Or, do you generally change materials frequently throughout the day? Further, how many parts do you make at a time? These are questions you must ask yourself prior to making a tooling decision.

Material Specific Tooling is best utilized where several parts are being machined of the same material. For instance, if your shop is machining 1,000 plastic parts, it would be in your best interest to opt for a tool designed for this material as your tooling would not only last longer but perform better. If machining flexibility is paramount for your shop, if you’re only machining a few parts, or if part finish is not of high importance, a regular end mill may suffice.

Pros and Cons of Material Specific Tooling

There are pros and cons to purchasing a Material Specific Tool.

Pros:

  • Tool geometry designed for the material you’re working in to achieve the best results.
  • Coating optimized for the material you’re cutting.
  • More aggressive speeds and feeds, and boosted MRR as a result.
  • Increased tool life.

Cons:

  • Higher upfront cost, though long term savings are possible if used in proper situations.
  • Less opportunity for flexibility. While most end mills may be suitable for use in many jobs and many machines, Material Specific End Mills are engineered for use in specific materials

Special Benefits of Material Specific Tooling

A Unique Internal Tool Geometry

Many manufacturers supply tooling designed for use in specific material buckets. For instance, Harvey Tool has distinct catalog sections for material specific tooling for Hardened Steels, Exotic Alloys, Medium Alloy Steels, Free Machining Steels, Aluminum Alloys, Plastics, Diamond Tooling for Non-Ferrous Materials, and Composites. The special geometry of tools found in these sections is optimized to allow the tool to perform optimally in its select material group.

For instance, a machinist may be faced with a dilemma while preparing to machine a plastic part. While an end mill found in Harvey Tool’s Miniature End Mill section could certainly machine this material, Harvey Tool’s end mill offering designed to machine plastics feature a high rake, high relief design. This is ideal for plastics because you want to effectively cut and form chips while the strength of the tool is less of a concern. The high rake and high relief creates a sharp cutting edge that would quickly break down in metals. However, in plastics, this effectively shears the material and transfers the heat into the chip to produce a great finish in your part.

material specific tooling

Harvey Performance Company, LLC.

Specific Coatings & Substrates for Optimal Performance

One key benefit of opting for a material specific tool is the ability to utilize the best coating option available for that material. Tool coatings serve many functions, including improved lubricity, increased tool life, and a higher-quality part finish. In addition, coated tools can typically be run around 10% faster than uncoated tools.

While many manufacturers will specially coat a standard end mill at your request, this takes added time and cost. In its Material Specific catalog sections, Harvey Tool offers coated tools stocked and ready to ship. For instance, their Hardened Steels and Exotic Alloys categories utilize AlTiN Nano coating. This is a unique nanocomposite coating that has a max working temperature of 2,100° F and shows improved performance in materials such as Hardened Steels, Titantium Alloys, and Inconel, among others.

Increased Material Removal Rates

Because Material Specific Tooling features optimal tool geometry for a job, running parameters are generally able to be more aggressive. Any machinist knows that Material Removal Rates (MRR), is the metric that’s most closely related to shop efficiency, as the more material removed from a part in a given period of time, the faster parts are made and the higher the shop output.

The following example compares running parameters of end mills from Harvey Tool’s Miniature End Mill and Material Specific End Mill Sections. You can notice that while key geometries between the two tools are identical, and are in use in the same material with the same operation, the chip load (+25%), linear feed rate (+33%), and depth of cut (+43%) are boosted. This allows for more material to be removed in a shorter period of time.

Miniature End Mill

Part Number: 836408

Description: 3 Flute 1/8 inch diameter 3x LOC Square Stub & Standard

Material: 6061 Aluminum

Application: Slotting

Speed: 10,000 RPM

Chip Load: .00124 IPT

Linear Feed: 37.2 IPM

DOC: .04375

material specific tooling

Harvey Performance Company, LLC.

 

Material Specific End Mill

Part Number: 942308

Description: 3 Flute 1/8 inch diameter 3x LOC Square Variable Helix for Aluminum Alloys

Material: 6061 Aluminum

Application: Slotting

Speed: 10,000 RPM

Chip Load: .00165 IPT

Linear Feed: 49.5 IPM

DOC: .0625

material specific tooling

Harvey Performance Company, LLC.

Extensive Cost Savings

The following chart displays a cost analysis breakdown between a tool found in the Miniature End Mill section, item 993893-C3; and a tool found in the Material Specific End Mill section, item 933293-C6. When compared for the machining of 1,000 parts, the overall savings is nearly $2,500.

material specific tooling

Material Specific Tooling Summarized

In conclusion, Material Specific End Mills have many benefits, but are best utilized in certain situations. While the initial cost of these tools are higher, they can work to save your shop time and money in the long run by lasting longer and producing more parts over a given period of time.

Confidently Select Your Next Thread Mill

Do you know the key differences between a Single Form Thread Mill and a Multi-Form Thread Mill? Do you know which tooling option is best for your job? This blog post examines how several factors, including the tool’s form and max depth of thread, are important to ultimately making the appropriate Harvey Tool thread mill decision.

Thread Mill Product Offering

Single Form Thread Mill

The single form thread mill is the most versatile threading solution Harvey Tool offers. These tools are ground to a sharp point and are capable of milling 60° thread styles, such as UN, metric, and NPT threads. With over 14 UN and 10 Metric sized tools, Harvey Tool’s single form selections allow machinists the opportunity to machine many different types of threads.

Thread Mill

Harvey Performance Company, LLC.

Single Form Thread Mills for Hardened Steels

Similar to the standard single form thread mills, Harvey Tool’s thread mills for hardened steels offer machinists a quality option when dealing with hardened steels from 46-68 Rc. The following unique geometries helps this tool machine tough alloys:

  1. Ground Flat – Instead of a sharp point these tools have a ground flat to help ensure long tool life.
  2. Eccentric Relief – Gives the cutting edges extra strength for the high feeds at relatively low RPMs required for harder materials.
  3. AlTiN Nano Coating – Allows for superior heat resistance.
thread mill

Harvey Performance Company, LLC.

A key difference between the standard Single Form Thread Mill and the Single Form Thread Mills for Hardened Steels is that the thread mills for hardened steels are actually only capable of milling 83% of the actual thread depth. At first, this may seem detrimental to your operation. However, according to the Machinery’s Handbook 29th Edition, “Tests have shown that any increase in the percentage of full thread over 60% does not significantly increase the strength of the thread. Often, a 55% to 60% thread is satisfactory, although 75% threads are commonly used to provide an extra margin of safety.” With the ability to preserve tool life and effectively perform thread components, Harvey Tool’s single form thread mills for hardened steels are a natural choice when tackling a hardened material.

Tri-Form Thread Mills

Tri-Form thread mills are designed for difficult-to-machine materials. The tri-form design reduces tool pressure and deflection, which results in more accurate threading. Its left-hand cut, left-hand spiral design allows it to climb mill from the top of the thread to the bottom.

thread mill

Harvey Performance Company, LLC.

Multi-Form Thread Mills

Our multi-form thread mills are offered in styles such as UN, NPT, and Metric. Multi-Form Thread Mills are optimized to produce a full thread in single helical interpolation. Additionally, they allow a machinist to quickly turn around production-style jobs.

thread mill

Harvey Performance Company, LLC.

Coolant-Through Multi Form Thread Mills

Coolant-Through Multi Form Thread Mills are the perfect tool for when a job calls for thread milling in a blind hole. The coolant through ability of the tool produces superior chip evacuation. These tools also improve coolant flow to the workpiece – delivering it directly from the tip of the tool – for decreased friction and high cutting speeds.

thread mill

Harvey Performance Company, LLC.

Long Flute Thread Mills

These tools are great when a job calls for a deep thread, due to their long flute. Long Flute Thread Mills also have a large cutter diameter and core, which provides the tool with improved tool strength and stability.

thread mill

Harvey Performance Company, LLC.

N.P.T. Multi-Form Thread Mills

While it may seem obvious, N.P.T. Multi-Form Thread Mills are perfect for milling NPT threads. NPT threads are great for when a part requires a full seal, different from traditional threads that hold pieces together without the water-tight seal.

thread mill

Harvey Performance Company, LLC.

Main Differences Between Engravers & Marking Cutters

While similar on the surface, Half-round Engraving Cutters and Marking Cutters are actually very different. Both tools are unique in the geometries they possess, the benefits they offer, and the specific purposes they’re used for. Below are the key differences between Engraving Cutters and Marking Cutters that all machinists must know, as the engraving on a part is often a critical step in the machining process.

Engravers & Marking Cutters Serve Different Purposes

All Marking Cutters are Engraving Cutters, but not all Engraving Cutters are Marking Cutters. This is because Marking Cutters are a “type” of engraving tool. By virtue of their sturdier geometry, Marking Cutters are suited for applications requiring repetition such as the engraving of serial numbers onto parts. Harvey Tool has been able to customize specific tool geometries for ferrous and non-ferrous applications, offering Marking Cutters for material specific purposes.

engraver

Engraving Cutters, on the other hand, are meant for finer detailed applications that require intricate designs such as engraving a wedding band or a complex brand design.

engraver

These Tools Have Unique Geometry Features

Historically, Engraving Cutters have been made as a half round style tool. This tool allows for a true point, which is better for fine detail, but can easily break if not run correctly. Because of this, Engraving Cutters have performed well in softer materials such as aluminum and wood, especially for jobs that require an artistic engraving with fine detail.

Marking cutters are not as widely seen throughout the industry, however. These tools hold up in harder-to-machine materials exceedingly well. Marking Cutters are a form of Engraving Cutter that contain 2 flutes and a web at the tip, meaning that the tool has a stronger tip and is less susceptible to breakage.

engraver

While these tools do not contain a true point (due to their web), they do feature shear flutes for better cutting action and the ability to evacuate chips easier when compared to a half-round engraver.

Harvey Tool Product Offering

Harvey Tool offers a wide variety of both Engraving Cutters and Marking Cutters. Choose from a selection of pointed, double-ended, tip radius, and tipped-off Engraving Cutter styles in 15 included angles ranging from 10° to 120°.

engraver

Marking Cutters are fully stocked in tip radius or tipped-off options, and are designed specifically for either ferrous or non-ferrous materials. Marking Cutters are offered in included angles from 20° to 120°.

While Engraving Cutters are offered uncoated or in AlTiN, AlTiN Nano, or Amorphous Diamond coatings, Marking Cutters are fully stocked in uncoated, AlTiN, or TiB2 coated styles.

Marking Cutters & Engravers Summarized

While both Engraving Cutters and Marking Cutters can accomplish similar tasks, each tool has its own advantages and purpose. Selecting the correct tool is based largely on preference and applicability to the job at hand. Factors that could impact your selection would be final Depth of Cut, Width of Cut, the angle needing to be achieved, and the desired detail of the engraving.

5 Questions to Ask Before Selecting an End Mill

Few steps in the machining process are as important as selecting the best tooling option for your job. Complicating the process is the fact that each individual tool has its own unique geometries, each pivotal to the eventual outcome of your part. We recommend asking yourself 5 key questions before beginning the tool selection process. In doing so, you can ensure that you are doing your due diligence in selecting the best tool for your application. Taking the extra time to ensure that you’re selecting the optimal tool will reduce cycle time, increase tool life, and produce a higher quality product.

Question 1: What Material am I Cutting?

Knowing the material you are working with and its properties will help narrow down your end mill selection considerably. Each material has a distinct set of mechanical properties that give it unique characteristics when machining. For instance, plastic materials require a different machining strategy – and different tooling geometries – than steels do. Choosing a tool with geometries tailored towards those unique characteristics will help to improve tool performance and longevity.

Harvey Tool stocks a wide variety of High Performance Miniature End Mills. Its offering includes tooling optimized for hardened steels, exotic alloys, medium alloy steels, free machining steels, aluminum alloys, highly abrasive materials, plastics, and composites. If the tool you’re selecting will only be used in a single material type, opting for a material specific end mill is likely your best bet. These material specific tools provide tailored geometries and coatings best suited to your specific material’s characteristics. But if you’re aiming for machining flexibility across a wide array of materials, Harvey Tool’s miniature end mill section is a great place to start.

Helical Solutions also provides a diverse product offering tailored to specific materials, including Aluminum Alloys & Non-Ferrous Materials; and Steels, High-Temp Alloys, & Titanium. Each section includes a wide variety of flute counts – from 2 flute end mills to Multi-Flute Finishers, and with many different profiles, coating options, and geometries.

Question 2: Which Operations Will I Be Performing?

An application can require one or many operations. Common machining operations include:

  • Traditional Roughing
  • Slotting
  • Finishing
  • Contouring
  • Plunging
  • High Efficiency Milling

By understanding the operations(s) needed for a job, a machinist will have a better understanding of the tooling that will be needed. For instance, if the job includes traditional roughing and slotting, selecting a Helical Solutions Chipbreaker Rougher to hog out a greater deal of material would be a better choice than a Finisher with many flutes.

Question 3: How Many Flutes Do I Need?

One of the most significant considerations when selecting an end mill is determining proper flute count. Both the material and application play an important role in this decision.

Material:

When working in Non-Ferrous Materials, the most common options are the 2 or 3-flute tools. Traditionally, the 2-flute option has been the desired choice because it allows for excellent chip clearance. However, the 3-flute option has proven success in finishing and High Efficiency Milling applications, because the higher flute count will have more contact points with the material.

Ferrous Materials can be machined using anywhere from 3 to 14-flutes, depending on the operation being performed.

Application:

Traditional Roughing: When roughing, a large amount of material must pass through the tool’s flute valleys en route to being evacuated. Because of this, a low number of flutes – and larger flute valleys – are recommend. Tools with 3, 4, or 5 flutes are commonly used for traditional roughing.

Slotting: A 4-flute option is the best choice, as the lower flute count results in larger flute valleys and more efficient chip evacuation.

Finishing: When finishing in a ferrous material, a high flute count is recommended for best results. Finishing End Mills include anywhere from 5-to-14 flutes. The proper tool depends on how much material remains to be removed from a part.

High Efficiency Milling: HEM is a style of roughing that can be very effective and result in significant time savings for machine shops. When machining an HEM toolpath, opt for 5 to 7-flutes.

end mill selection

Question 4: What Specific Tool Dimensions are Needed?

After specifying the material you are working in, the operation(s) that are going to be performed, and the number of flutes required, the next step is making sure that your end mill selection has the correct dimensions for the job. Examples of key considerations include cutter diameter, length of cut, reach, and profile.

Cutter Diameter

The cutter diameter is the dimension that will define the width of a slot, formed by the cutting edges of the tool as it rotates. Selecting a cutter diameter that is the wrong size – either too large or small – can lead to the job not being completed successfully or a final part not being to specifications.  For example, smaller cutter diameters offer more clearance within tight pockets, while larger tools provide increased rigidity in high volume jobs.

Length of Cut & Reach

The length of cut needed for any end mill should be dictated by the longest contact length during an operation. This should be only as long as needed, and no longer. Selecting the shortest tool possible will result in minimized overhang, a more rigid setup, and reduced chatter. As a rule of thumb, if an application calls for cutting at a depth greater than 5x the tool diameter, it may be optimal to explore necked reach options as a substitute to a long length of cut.

Tool Profile

The most common profile styles for end mills are square, corner radius, and ball. The square profile on an end mill has flutes with sharp corners that are squared off at 90°. A corner radius profile replaces the fragile sharp corner with a radius, adding strength and helping to prevent chipping while prolonging tool life. Finally, a ball profile features flutes with no flat bottom, and is rounded off at the end creating a “ball nose” at the tip of the tool. This is the strongest end mill style.  A fully rounded cutting edge has no corner, removing the mostly likely failure point from the tool, contrary to a sharp edge on a square profile end mill. An end mill profile is often chosen by part requirements, such as square corners within a pocket, requiring a square end mill.  When possible, opt for a tool with the largest corner radius allowable by your part requirements. We recommend a corner radii whenever your application allows for it. If square corners are absolutely required, consider roughing with a corner radius tool and finishing with the square profile tool.

Question 5: Should I use a Coated Tool?

When used in the correct application, a coated tool will help to boost performance by providing the following benefits:

  • More Aggressive Running Parameters
  • Prolonged Tool life
  • Improved Chip Evacuation

Harvey Tool and Helical Solutions offer many different coatings, each with their own set of benefits. Coatings for ferrous materials, such as AlTiN Nano or TPlus, typically have a high max working temperature, making them suitable for materials with a low thermal conductivity. Coatings for non-ferrous applications, such as TiB2 or ZPlus, have a low coefficient of friction, allowing for easier machining operations. Other coatings, such as Amorphous Diamond or CVD Diamond Coatings, are best used in abrasive materials because of their high hardness rating.

Ready to Decide on an End Mill

There are many factors that should be considered while looking for the optimal tooling for the job, but asking the aforementioned five key question during the process will help you to make the right decision. As always, The Harvey Performance Company Technical Service Department is always available to provide recommendations and walk you through the tool selection process, if need be.

Harvey Tool Technical Support: 800-645-5609

Helical Solutions Technical Support: 866-543-5422

Experience the Benefits of Staggered Tooth Keyseats

Keyseat Cutters, also known as Woodruff Cutters, Keyway Cutters, and T-Slot Cutters, are commonly used in machine shops. Many machinists opt to use this tool to put a slot on the side of a part in an efficient manner, rather than rotating the workpiece and using a traditional end mill. A Staggered Tooth Keyseat Cutter has alternating right-hand and left hand shear flutes and is right-hand cut, whereas a traditional keyseat cutter has all straight flutes and is right-hand cut. Simply, the unique geometry of a Staggered Tooth Keyseat Cutter gives the tool its own set of advantages including the ability to index within the slot, increase feed rates, and achieve better part finish.

staggered tooth keyseat cutter

Three Key Benefits

Indexing

The alternating right-and-left-hand flutes of a Harvey Tool Staggered Tooth Keyseat Cutters are relieved on both sides of its head, meaning that it allows for both end cutting and back cutting. This adds to the versatility of the staggered tooth keyseat cutter, where one singular tool can be indexed axially within a slot to expand the slot to a specific uncommon dimension. This can save space in a machinist’s magazine and reduce machine time by eliminating the need to swap to a new tool.

Increased Feed Rates

Due to the unique geometry of a Staggered Tooth Keyseat Cutter, chips evacuate efficiently and at a faster rate than that of a Straight Flute Keyseat Cutter. The unique flutes of Staggered Tooth Keyseat Cutters are a combination of right-and-left-hand shear flutes, but both types are right-hand cutting. This results in the tool’s teeth alternating between upcut and downcut. Chip packing and chip recutting is less of a concern with running this tool, and results in increased chip loads compared to that of a standard keyseat with the same number of flutes. Because of this, the tool can account for chiploads of about 10% higher than the norm, resulting in heightened feed rates and shorter cycle times overall.

Better Part Finish

Staggered Tooth Keyseat Cutters have “teeth”, or flutes, that are ground at an angle creating a shear flute geometry. This geometry minimizes chip recutting, chip dragging and reduces the force needed to cut into the material. Chip recutting and dragging are minimized because chips are evacuated out of the top and bottom of the head on the side of the cutter that is not engaged in the material. Shear flutes also reduce vibrations that can lead to chatter and poor finish. By minimizing cutting forces, vibration, and chatter, a machinist can expect a better part finish.

staggered tooth keyseat cutter

Image courtesy of @edc_machining

Staggered Tooth Keyseat Cutter Diverse Product Offering

On top of the higher performance one will experience when using the Stagger Tooth Keyseats, there are also multiple options available with various combinations to suit multiple machining needs. This style is offered in a square and corner radius profile which helps if a fillet or sharp corner is needed. There are also multiple cutter diameters ranging from 1/8” to 5/8”. The increased diameter comes with an increase of radial depth of cut, allowing deeper slots to be achievable. Within the most popular cutter diameters, ¼”, 3/8”, and ½” there are also deep slotting options with even greater radial depth of cuts for increased slot depths. On top of the diameters and radii, there are also multiple cutter widths to choose from to create different slots in one go. Finally, an uncoated and AlTiN coatings are available to further increase tool life and performance depending on the material that is being cut.

Opt for a Smoother Operation

A Staggered Tooth Keyseat Cutter adds versatility to a tool magazine. It can be indexed axially to expand slots to make multiple widths, allowing machinists to progress operations in a more efficient manner where tool changes are not required. Further, this tool will help to reduce harmonics and chatter, as well as minimize recutting. This works to create a smoother operation with less force on the cutter, resulting in a better finish compared to a Standard Keyseat Cutter.

For more information on Harvey Tool Staggered Tooth Keyseat Cutters and its applications, visit Harvey Tool’s Keyseat Cutter page.

How To Maximize High Balance End Mills

High speed machining is becoming increasingly widespread in machine shops all over the world due to the proven benefits of greater efficiency and productivity through increased spindle speeds and metal removal rates.  However, at such high spindle speeds, otherwise negligible errors and imperfections can cause negative effects such as reduced tool life, poor surface finish, and wear on the machine itself. Many of these negative effects stem from an increase in total centrifugal forces leading to vibration, commonly referred to in the industry as chatter. A key contributor to vibrations and one of the more controllable factors, is tool unbalance.

Why Balance is Critical to Machining

Unbalance is the extent to which the tool’s center of mass diverges from its axis of rotation.  Small levels of unbalance may be indistinguishable at lower RPMs, but as centrifugal force increases, small variations in the tool’s center of mass can cause substantial detrimental effects on its performance. High Balance End Mills are often used to help solve the problem of vibrations at the increased spindle speeds. Balancing is used to make compensation for the intrinsic unsymmetrical distribution of mass, which is typically completed by removing mass of a calculated amount and orientation.

Image Source: Haimer; Fundamentals of Balancing

Helical Solutions offers High Balance End Mills in both 2 and 3 flute options (see Figure 2), square and corner radius, along with coolant-through on the 3 fluted tools. These end mills are balanced at the industry standard of G2.5 at 33,000 RPM: G stands for the potential damage due to unbalance, which can be expressed as “Balancing Quality Grade” or G and 2.5 is the vibration velocity in MM per second. These tools are designed specifically to increase performance in highly balanced machining centers that are capable of elevated RPMs and feed rates. With high balance tooling, improved surface finishes are also achieved due to reduced vibrations during the machining process. Additionally, these end mills have been designed around current high-end tool holding, and come in a variety of neck lengths at specific overall lengths. These dimensional combinations result in maximum rigidity and reduced excess stick out, allowing for optimal performance and the ability to push the tools to the limit.

High Balanced Tooling Cost Benefits

Machinists who choose to use High Balance End Mills will see certain benefits at the spindle, but also in their wallets. Cost benefits of opting to run this type of tool include:

Utilizing Tap Testers

What Tap Testers Do

Vibrations are your applications worst enemy, especially at elevated RPMs and feed rates. Using resources such as a Tap Tester can help decrease vibrations and allow you to get the most out of your High Balance End Mills by generating cutting performance predictions and chatter limits.

How Tap Testing Works

High balance

Image Source: Manufacturing Automation Laboratories Inc.

Tap Testing generates cutting performance predictions and chatter limits. In a tap test, the machine-tool structure is “excited,” or tested, by being hit with an impulse hammer. In milling, the machine-tool structure is usually flexible in all three directions: X, Y, and Z, but in milling applications where High Balance Tooling is used, the flexibility is commonly only considered in two planes – the X and Y directions. By hitting the X and Y directions with the impulse hammer, the impact will excite the structure over a certain frequency range that is dependent on the hammer’s size, the type of tool being used, and the structure itself. The frequencies generated from the initial hit will produce enough information that both the impact force measurement and the displacement/accelerometer measurement are available. Combining these two measurements will result in the Frequency Response Function, which is a plot of the dynamic stiffness of the structure in frequencies.

After the information from the Tap Test is gathered, it will then process the information into useful cutting parameters for all spindles speeds such as cut depths, speed rates, and feed rates. In knowing the optimum running parameters, vibrations can be minimized and the tool can be utilized to its full potential.

High Balanced Tooling Summarized

Keeping vibrations at bay during the machining process is extremely important to machining success. Because one cause of vibration is tool unbalance, utilizing a balanced tool will result in a smoother job, a cleaner final product, and a longer life of both the tool and spindle. Machinists who choose to use High Balance Tooling can utilize a Tap Tester, or a method for generating the perfect running parameters for your tool and machine setup to ensure that machining vibration is as minimal as possible.

Shank Tolerances, Collet Fits, & h6 Benefits

A cutting tool’s shank is one of the more vital parts of a tool, as it’s critical to the collet-tool connection. There are several types of shanks, each with their own tolerances and suitable tool holder methods. One of the most popular and effective tool holding styles is a shrink fit tool holder, which works with h6 shanks, but what does this mean and what are the benefits of it? How is this type of shank different from a shank with standard shank tolerances? To answer these questions, we must first explore the principals of tolerances.

The Principals of Tolerances

Defining Industry Standard Tolerances

There are two categories of shank tolerances that machinists and engineers operating a CNC machine should be familiar with: hole basis and shank (or shaft) basis. The hole basis system is where the minimum hole size is the starting point of the tolerance. If the hole tolerance starts with a capital “H,” then the hole has a positive tolerance with no negative tolerance. The shank basis system is where the maximum shank size is the starting point. This system is relatively the same idea as the hole basis system but instead, if the tolerance starts with a lowercase “h,” the shank has a negative tolerance and no positive tolerance.

Letter Designations

The limits of tolerance for a shank or hole are designated by the appropriate letter indicating the deviation. For instance, the letter “k” has the opposite minimum and maximum designations as “h”. Tolerances beginning with “k” are exclusively positive, while tolerances beginning with “h” are exclusively negative. The number following the given letter denotes the International Tolerance (IT) grade. For example, a tolerance with the number 6 will have a smaller tolerance range than the number 7, but larger than the number 5. This range is based on the size of the shank. A hole that has a 0.030” diameter will have an h6 tolerance of (+0.0000,-0.0002), while a 1.00” hole with have an h6 tolerance band of (+0.0000,-0.0005).

It is important to note that most sources list IT tolerances in millimeters, while the graph below has been translated to inches. Operations that require more precise manufacturing, such as reaming, will have lower IT grades. Operations that do not require manufacturing to be as precise will have higher IT grades.

shank tolerances

Preferred Collet Fits

Different types of combinations of hole basis and shank basis tolerances lead to different types of collet fits. The following table offers insight into a few different types of preferred fits and the shank tolerances that are required for each.

collet fits

Image: Machinery’s Handbook 29th Edition.

Shrink Fit Tool Holders

The shrink fit holder is one of the more popular styles of tool holders because of its ability to be more customizable, as evident in the chart above. In this method, a collet is heated to expand, then cooled to contract around the shank of a tool. At room temperature, a cutting tool should not be able to be inserted into a shrink fit holder – only when the holder has undergone thermal expansion due to the introduction of a significant amount of heat should the tool fit. As the holder cools, the tool is held tighter and tighter in place. Typically, a holder is heated through a ring of coils by an induction heater. It is important to heat the holder uniformly, paying mind to not overheat it. Doing so could cause the shank that is being held to expand within the holder and remain stuck.

 

Benefits of Shrink Fit Tool Holders

  1. Gripping power. The shank is held flush and uniform against the holder, resulting in a tighter connection.
  2. Low runout. A more secure connection will result in extended tool life, and a higher quality surface finish.
  3. Better balance for high RPM. With a tighter tool-to-holder connection, the opportunity exists for more aggressive running parameters.

Shank Tolerances Summarized

Understanding shank tolerances is an intricate part of the machining process as it impacts which tool holder is appropriate for your job. A secure holder connection is vital to the performance of the tool in your application. With an h6 shrink fit holder, the result is a secure connection with stronger gripping power. However, only certain shanks are able to be used with this type of holder. From the letter designation assigned to a shank, to whether that letter is upper or lowercase, each detail is vital to ensuring a proper fit between your tools shank and its corresponding shrink fit holder.

Drill / End Mills: Drill Style vs. Mill Style

Drill / End Mills are one of the most versatile tools in a machinist’s arsenal. These tools can perform a number of different operations, freeing space on your carousel and improving cycle times by limiting the need for tool changes. These operations include:

  1. Drilling
  2. V-Grooving
  3. Milling
  4. Spot Drilling
  5. Chamfering

The ability of the Drill / End Mill to cut along the angled tip as well as the outer diameter gives it the range of operations seen above and makes it an excellent multi-functional tool.

drill mill operations

Drill Style vs. Mill Style

The main difference between Drill / End Mill styles is the point geometry.  They are defined by how the flutes are designed on the end of the tool, using geometry typically seen on either an end mill or a drill.  While mill style tools follow the features of an end mill or chamfer mill, the drill style geometry uses an S-gash at the tip.  This lends strength to the tip of the tool, while giving it the ability to efficiently and accurately penetrate material axially.  While both styles are capable of OD milling, mill style tools will be better for chamfering operations, while drill style will excel in drilling.  The additional option of the Harvey Tool spiral tipped Drill / End Mill is an unprecedented design in the industry.  This tool combines end geometry taken from our helical flute chamfer cutters with a variable helix on the OD for enhanced performance. Versatility without sacrificing finish and optimal performance is the result.

drill mills

Left to Right: 2 Flute Drill Style End, 2 Flute Mill Style End, 4 Flute Mill Style End

Drill Mills: Tool Offering

Harvey Tool currently offers Drill / End Mills in a variety of styles that can perform in different combinations of machining applications:

Mill Style – 2 Flute

This tool is designed for chamfering, milling, drilling non-ferrous materials, and light duty spotting. Drilling and spotting operations are recommended only for tools with an included angle greater than 60°. This is a general rule for all drill mills with a 60° point. Harvey Tool stocks five different angles of 2 flute mill-style Drill / End Mills, which include 60°, 82°, 90°, 100° and 120°. They are offered with an AlTiN coating on all sizes as well as a TiB2 coating for cutting aluminum with a 60° and 90° angle.

drill mill

Mill Style – 4 Flute

4 flute mill-style Drill / End Mills have two flutes that come to center and two flutes that are cut back. This Drill / End Mill is designed for the same operations as the 2 flute style, but has a larger core in addition the higher flute count. The larger core gives the tool more strength and allows it to machine a harder range of materials. The additional flutes create more points of contact when machining, leading to better surface finish. AlTiN coating is offered on all 5 available angles (60°, 82°, 90°, 100°, and 120°) of this tool for great performance in a wide array of ferrous materials.

drill mill

Drill Style – 2 Flute

This tool is specifically designed for the combination of milling, drilling, spotting and light duty chamfering applications in ferrous and non-ferrous materials. This line is offered with a 90°, 120°, and 140° included angle as well as AlTiN coating.

drill mills drill style

Helical Tip – 4 Flute

The Helically Tipped Drill / End Mill offers superior performance in chamfering, milling and light duty spotting operations. The spiral tip design allows for exceptional chip evacuation and surface finish. This combined with an OD variable helix design to reduce chatter and harmonics makes this a valuable tool in any machine shop. It is offered in 60°, 90°, and 120° included angles and comes standard with the latest generation AlTiN Nano coating that offers superior hardness and heat resistance.