Optimize Your Parting-Off and Grooving Operations

By Don Halas, Product Manager – Threading & MDT

Parting-off and grooving processes involve tight, narrow cutting zones that create singular challenges regarding tool strength and rigidity as well as chip control. Therefore, tool manufacturers are employing innovative tooling designs and advanced coolant delivery strategies that meet the special requirements of these processes. 

X4 Multi-edged Tangential Tool

Consider our new X4 series of slender, highly robust tangential inserts with four cutting edges. The series minimizes material consumption in parting-off operations and enables precise grooving of small and medium-sized complex parts. These inserts provide narrow cutting widths from .031” to .94” and cutting depths between 0.20” and 0.52”. 

Keep in mind, however, narrower-style inserts can produce instability in the cut. Therefore, holding the insert with the shortest blade possible and clamping it in the largest tool shank that does not interfere with the workpiece will help control vibration.

The good news for X4 users is that it is available in several tool shank sizes and the tangential inserts direct the cutting forces into the holder to maximize rigidity, stability and productivity. Furthermore, all of the insert types fasten into the same easy-to-load toolholder for increased flexibility and a reduction in tooling inventory. 

The limited cutting zone space in parting-off and grooving operations creates chip control problems. The workpiece material surrounds the cutting tool on both sides while it is in the cut, restricting the chips’ path of escape. An uncontrolled continuous chip can jam in the cut, mar the workpiece and endanger the operator. However, the X4 can apply an MC chipbreaking geometry that will bend the chips and break them if possible.

Another method for chip control is the application of coolant, which can flush away chips that otherwise might clog the cutting zone. However, traditional flood coolant usually has insufficient pressure to reach the cutting zone in parting-off and grooving applications. It is also difficult to position flood coolant nozzles for optimum placement of the coolant stream. An alternative to flood coolant is coolant applied at high pressure and as close to the cutting edge as possible. 

Consequently, our new Jetstream Tooling® Duo technology, which is incorporated with the X4 toolholders, delivers direct, high-pressure coolant from two outlets. In addition to upper jets that are directed to the optimal point of the rake face, the new Duo technology uses an additional coolant jet to flush the clearance surface. The cutting edge receives high-press coolant from opposite directions – above and below – maximizing the control of the chip flow as well as cooling the cutting zone. 

As you can see, modern parting-off and grooving tools and technology play a big role in optimizing this specialized but important group of machining processes. If you are interested in learning more about how the X4 can improve your operations, please don’t hesitate to contact me. 

Watch the X4 in action.

About the Author

As product manager for threading and grooving at Seco, Don is responsible for threading, threadmilling, cut-off, grooving and oil field chasers. In his spare time, he enjoys restoring old motorcycles. Contact Don at dhalas@secotools.com.

Tips for HRSA Machining with Ceramic Inserts

By Chad Miller, Product Manager – Advanced Materials

CS100 ceramic grade

Our new CS100 ceramic grade provides excellent rough machining performance in heat-resistant super alloys (HRSA), including Inconel, MAR, RENE, Nimonic and Waspaloy. We designed this grade to reduce machining time and increase productivity by allowing for higher cutting speeds. In fact, the high-speed capabilities of ceramic result in metal removal rates that are four to eight times greater than carbide.

However, to effectively utilize the CS100 at high speeds, your workpiece set up and machining conditions need to be as stable as possible to prevent chipping of the grade. Here are some important tips to keep in mind before utilizing this sialon-based solution.

Toolholders

It’s best to use a toolholder that’s intended for securely holding ceramic inserts. You can gain improved stability by choosing a toolholder with a large shank size, such as boring bars made from heavy metal or carbide. 

As with any machining process, it’s important to keep your tool overhang as short as possible. However, when long overhangs are unavoidable, such as in boring applications, it’s best to avoid negative inserts due to high radial cutting forces. Instead, go with a positive insert geometry and tool holder combination with a 90-degree angle between the leading edge of the insert and the machining surface.  

When machining high-temperature materials, you can improve tool life by using toolholders with large lead angles, as those less than 15 degrees will leave you unsuccessful. A large lead angle will thin out your chips and possibly increase your cutting parameters. 

Inserts

You should utilize the strongest insert geometry possible for your application. A round insert works best in roughing operations, and you’ll want to keep its arc of engagement low (not to exceed 45 degrees) to prevent chatter and slippage. However, if a round insert isn’t an option, then choose an insert with the largest possible radius. Also, the thicker the insert the more strength and predictable tool life you’ll have. 

Insert geometry strength from highest to lowest:

• Round

• 100-degree corner of 80-degree diamond

• 80-degree diamond

• Trigon

• Triangle

• 55-degree diamond

• 35-degree diamond

Having the correct edge prep for your workpiece material is also an important consideration. A chamfered edge with a hone is preferred for applications that involve the roughing of high-temperature materials.   

Coolant

Concentration-level controlled flood coolant is important when machining with ceramic tooling – and you’ll want plenty of it, as an intermittent coolant supply will make for a disastrous situation. The coolant should also be clean because any contamination will shorten your tool life. 

You should not use high-pressure or high-velocity coolant (1000 + psi) during the machining process. Doing so reduces the temperature of the cutting zone and keeps the material from softening, thereby increasing cutter forces and accelerating tool wear. High-pressure coolant also causes erosion that will, in turn, decrease tool life. You also don’t want to use oil as a cutting fluid as that becomes a fire and smoke hazard.  

Application of Inserts

Insert geometry and radius size influence what feed rate you can effectively run in your machining operations. For instance, the weaker your geometry and the smaller your radii, the lower your feed rate must be. When possible, you should use larger radius sizes when machining components with large diameters. If smaller radii are absolutely necessary, then you must reduce your feed rate. 

These are just a few items to consider when machining with ceramic tooling, so if you’re interested in learning more, please don’t hesitate to contact me. I’d also be glad to go into detail on how the new CS100 can decrease your cost per part and improve your overall machining performance. 

About the Author

Chad manages Seco's advanced materials product lines, including all CBN and PCD products. When he's not helping customers implement advanced metalcutting solutions, you can find him training for and running 5K, 10K and 1/2 marathon races and triathlons. Chad can be reached at cmiller@secotools.com.

Tips for Purchasing a Face Mill Cutter With Multiple Edges

By Todd Miller, Manager, Rotating Products

Today’s shops want a cutting tool that offers high productivity, versatility and accuracy at a low cost per edge. In response, cutting tool companies, including Seco, are developing new precision-based solutions that offer improved economy through even more cutting edges per insert and better efficiency by performing both roughing and finishing operations.

Double Octomill

Take the latest generation of face milling tools for example. They all feature pre-hardened cutter bodies that maximize tool life and performance, as well as make use of inserts with as many as 16 cutting edges – our Double Octomill for example  – to minimize cost per edge for a lower cost per part.

Some companies have even placed high emphasis on creating the perfect fit between the insert and its corresponding pocket to maximize the effectiveness, performance and tool life of a cutter. For instance, with our Double Octomill, we are the only cutting tool company to develop insert pockets that incorporate a strong center lock screw and precisely located HSS pins that remarkably reduce radial and axial runout.

But in order to purchase the right cutter for your needs, you must weigh the different options that are available to you, considering variables such as workpiece material and hardness, application type, cost per insert, cost of edges in the cut per load, number of indexes needed to complete a job, cutter style, cutting diameters, cycle time, and much more.

Here are some important items to keep in mind before purchasing a face milling cutter with multiple cutting edges:

• Make sure you have a wide variety of insert grades and geometries to choose from so your cutter can operate in various materials and processes. Take our Duratomic coating for example, a breakthrough in coating technologies that improves productivity and tool life in many different materials.

• With respect to insert geometry, those with small wipers are ideal for roughing operations, while wider wiper edges can perform roughing and finishing in a single operation, producing superior surface finishes. For example, our M14 geometry with a 0.45 mm wiper flat is ideal for roughing, while the M15 with a 2.11 mm wiper flat is more suitable for finishing operations. Our M13, which has the same wiper flat as the M15 but has a more positive geometry, is perfect for longer chipping materials or where reduced cutting forces are needed.

• Make sure the inserts are easy to handle and have numbering on each edge. You should index all of the inserts at the same time and in the chronological number order. By using the same edge number in all of the pockets, the inserts are oriented the exact same way as the pressing tool that produces them, which, in turn, reduces pocket-to-pocket runout so you can achieve the best possible tool life.

• Given the wide variety of machines and materials available today, it’s important to have the right cutter pitch for your face milling operation. In cast iron applications where a machine has high-power capabilities, a close pitch cutter is often the best option. However, a close pitch cutter paired with a weak machine often results in unwanted vibrations. Using a close pitch cutter in long chipping materials usually results in chip jamming in the chip flutes. Normal and coarse pitch cutters use fewer teeth/inserts in the cutter so they require less torque, making them better solutions for machines with limited power capabilities. They also have larger chip flutes, providing better chip evacuation in longer chipping materials such as steel and stainless steels.

• Given all of the different cutter options available, including 45-degree cutters, square shoulder cutters and round insert cutters, you need to determine which one brings the most benefit to your operation. After all, one option may be better if you want to reduce your cutting forces, while another may be needed for a particular part feature.

• While a high-performance cutter with multiple insert edges may cost more up front, it can save you in the long run through increased tool life, lower cost per edge and an overall lower cost per part. Keep in mind, however, not every application benefits from this type of cutter.

Because there are so many machining variables to consider, you should also evaluate the cutting tool company selling a particular cutter and see what level of customer support it provides. After all, application support can be a major source of improved productivity, but it is one manufacturers often overlook.

   

Utilizing a cutting tool company’s in-depth knowledge of manufacturing technology as a resource allows you to stay abreast of the latest advancements in manufacturing, as well as understand how those innovations play into process optimization. The end result is that you can continue to increase your competitive advantage and differentiate your shop as a technology leader in the increasingly challenging global market.

About the Author

Todd is the manager of rotating products for NAFTA, responsible for solutions and applications involving face, square shoulder and disc milling. Todd and his team of product experts are dedicated to providing a consistent, high-level of support to Seco customers throughout the United States, Canada and Mexico. In his spare time, Todd likes to bowl and cheer on the University of Michigan football team.

Standard Versus Custom Tooling

By Bob Goulding, Technical Engineering Manager

Essentially thousands of cutting tools saturate the market today. Because of this, manufacturers can optimize most of their operations with standard tooling. Given the rapid and constant change of the industry, however, there will be those special applications that require a custom solution.

And by custom, that can mean something as simple as adding a half-inch to the diameter of a square shoulder mill cutter or as complex as developing a highly specialized form milling cutter. A combination tool is a great example of a custom solution as it can perform multiple operations, such as milling and drilling, with one tool, decreasing indexing time and increasing productivity.

If you’re going to specify a custom tool for a job, there are a few things you should consider. First of all, a custom solution is typically more expensive than standard tooling. But if a custom tool is going to offer you productivity-boosting benefits, including longer tool life and faster machining speeds, the additional cost becomes insignificant.

Secondly, because custom tooling is not an off-the-shelf solution, it's not readily available. So, if you were to have a machining problem and break every custom tool in your shop, you would experience downtime due to the delivery time associated with replacement custom tooling. For this reason alone, we work hard to find a standard solution that can meet the unique needs of our customers. If we can’t, we work equally as hard to provide the fastest turnaround time on a custom solution.

Lastly, you need to make sure your machine tool can handle the intended capabilities of your custom tool. There are cases where existing machining equipment can’t meet the expectations a manufacturer has when switching from standard to custom tooling, namely in increased power or rigidity of the setup. Also, don’t forget to assess the skill level of your machinists when transitioning over to a custom tool.  

At Seco, we can help you iron out all the details and determine if custom tooling is right for you. After all, we provide more than just cutting tools, we provide complete solutions. Our custom tooling team possesses extensive expertise in all major industry segments, including aerospace, automotive, oil and gas, medical and energy.

We work closely with our customers to determine exactly what they need and then create a solution that will optimize their unique operations. Furthermore, our custom tooling division in North America is one of 12 globally networked locations, providing us access to expertise from our colleagues worldwide.

Most recently, we’ve experienced increased demand for custom tooling, especially solutions for the automotive industry. Because automotive manufacturers produce high volumes of components daily, they rely on our combination custom tooling to remove significant cycle times from their operations for improved throughput.

If you’re curious as to how our custom tooling team can benefit your operations, please don’t hesitate to contact me.

About the Author

Bob is the technical engineering manager for Seco Tools in North America. He is responsible for overseeing and driving the organization towards its goals of helping customers overcome their manufacturing challenges so they can remain competitive in their respective industries. The organization includes proposal, quote and design tooling engineers for custom applications who work together with Seco’s process project managers whose focus is on customer component productivity improvements. The group also includes Seco’s machine tool organization and the manufacturing unit for tool production. In his spare time, Bob is an avid soccer enthusiast, both watching and playing and also supporting his kids in their respective teams. 

Diamond Cutting Tools: Your New Best Friend?

By Don Graham, Manager of Education and Technical Services

Marilyn Monroe sang about diamonds being a girl’s best friend, but if you’re machining high-performance parts from advanced non-ferrous materials, these little gems could possibly be your best friend, too – especially if you’re dealing with high demands and limited capacity.

Diamond is the hardest and most abrasion resistant material known to man, making it a brilliant cutting solution for the manufacturing industry. This is especially true for the aerospace and automotive sectors where polycrystalline diamond (PCD) and diamond-coated tools can offer amazing productivity advantages through extra long tool life and extremely fast cutting parameters. In fact, a diamond coating can bring 10 times more tool life to a cemented carbide cutting tool.

Overall, diamond tooling takes machining to levels of performance that carbide simply cannot go, significantly reducing the frequency of tool replacements and enabling machines to make parts at much higher rates. It is important, however, to remember that while the upfront cost of diamond tooling can cause sticker shock, the long-term benefits of these solutions can bring some serious bling to a bottom line.

Let’s suppose you’re using carbide tooling to machine aluminum at 2,000 surface feed per minute. By switching to diamond tooling, you have a solution that will last for what seems like forever and can machine as high as 10,000 surface feed per minute. This results in you machining five times as many parts in the same amount of time with the same number of machines and operators as before.

As such, your cost per part drops dramatically, and you can do one of two things. You can either make a lot more profit per part, or you can reduce the selling price of each part to enable your company to gain increased market share. Keep in mind, the latter choice would help keep more manufacturing jobs here in the United States as opposed to going overseas.    

If you think diamond tooling could be your new best friend, here are some things you should first consider:   

• The biggest payback from using diamond tools comes with machining abrasive materials. For example, the aluminum automotive manufacturers use to build engine blocks is very abrasive, having silicon and silicon carbide particles that can really grind away at a cutting tool. With carbide tooling, these manufacturers may run at 500 surface feed per minute and get 10 minutes of tool life. Diamond tooling, on the other hand, would allow them to machine at 5,000 surface feed per minute and get a couple of hours of tool life.      

• Diamond cutting tools have a need for speed and can reach their full potential with machine tools more suitable to them. However, if these fast machines are way too expensive for a manufacturer, a slower machine equipped with diamond tooling will still achieve higher levels of productivity versus one using carbide or high-speed steel tooling.

• Preventing the aluminum from sticking to the cutting edge is important for maintaining a good surface finish. Therefore, the machine tool used in conjunction with diamond tooling should always be running fast enough to avoid metal build-up. There are also specialized coolants that can assist in preventing built-up edge.     

• Diamond tooling is not suitable for use in all materials. While aluminum, titanium, hard steels, composites and graphite materials are all appropriate for diamond tooling, steels, stainless steels and cast irons are NOT. Diamond is made out of carbon, and carbon reacts with iron to form iron carbide – essentially, it is an atomic reaction that turns diamond into pencil lead (graphite).  

• PCD tooling, which involves taking diamond particles and hot pressing them together, is more expensive than diamond-coated tooling. However, it offers higher wear resistance and yields a better surface finish than diamond-coated tooling.

• Diamond-coated carbide tooling offers better chip control and has more geometric flexibility than PCD tooling. Practically any tool shape, from endmills to turning inserts with chip grooves, can have a diamond coating. And while PCD tooling may produce better surface finishes, diamond-coated tooling is better at machining graphite components and composite materials. But like any other cutting tool, the life of a diamond-coated tool varies based on part geometry, material type, and speed and feeds.

• Twenty years ago, there was a problem with diamond coatings peeling off carbide cutting tools, creating a stigma that still exists with many manufacturers today. However, peeling is no longer an issue because cutting tool manufacturers prevent it by selecting compatible carbide chemistry as well as using suitable preparation techniques and proper reactor conditions.

• The long tool life of diamond tools make them ideal for large machining volumes or long cuts. After all, it takes a lot of cutting for a manufacturer to be able to capture all the useful life the tool can deliver.   

It’s obvious diamond cutting tools can bring clear-cut advantages to advanced part-processing applications by allowing for increased operating speeds without sacrificing tool life. And while adding these tools to your operations can be an expensive business decision right out of the gate, you will definitely benefit in the long run if your goal is to accommodate more orders or achieve greater output. If you have any questions about diamond cutting tools, please don’t hesitate to contact a Seco applications expert.

About the Author

Don is the manager of education and technical services for Seco, responsible for all educational activities for the NAFTA market, new product testing and various other technical functions. Outside of work, he enjoys making maple syrup, restoring antique tractors and farming. Contact Don at dgraham@secotools.com.

Why You Should Care About Average Chip Thickness

By Todd Miller, Manager, Rotating Products

If you’ve ever had premature insert failure, poor surface finish or work hardening issues when milling, it’s often the result of not having the correct average chip thickness. By calculating average chip thickness and finding the proper feed per tooth, you can eliminate problems with finish, vibration and deflection as well as achieve peak productivity and tool life. 

It has been my experience, however, that people either overlook or misunderstand this basic milling principle. They often don’t realize how chip formation differs between turning and milling. In turning, chip formation remains the same throughout the cut because the feed rate remains constant. Chip formation in milling, on the other hand, varies as the insert moves in and out of the cut. 

Chip thickness is the thickness of the non-deformed chip at the right angles of the cutting edge, and it is influenced by the radial engagement, edge preparation of the insert and feed per tooth. Keep in mind, however, that different radial widths of cut and different lead angles require feed rate adjustments to maintain proper chip thickness. For example, when using a 90 degree lead indexable milling cutter, if your radial depth of cut is less than 50 percent of the cutter diameter, you must increase your feed rate to maintain appropriate average chip thickness. 

Chip thickness is the thickness of the non-deformed
chip at the right angles of the cutting edge.

Furthermore, it’s important to have the thickness of the chip equal or exceed the edge preparation on your insert, and there are charts and formulas you can use to calculate the correct feed rate for maintaining average chip thickness. These charts and formulas are in the back of our milling catalog. However, there are some key things you need to consider before making average chip thickness calculations.   

• Know the average chip thickness (Hm) value associated with your insert. We assign  designations to our inserts to make determining this value easy. If you have an M15, for example, the “M” stands for medium operations and the “15” indicates the average chip thickness in metric (.15 mm) based on the insert’s edge design. Your average chip thickness value is a key indicator in determining your minimum feed rates.

• Evaluate the radial width of your cut and determine what percentage of radial engagement you must have. The smaller the radial engagement the larger the feeds you will have. 

• Know the lead angle of your cutter, which is the angle that is formed between the outer edge of the insert and the center axis of the cutter. A lead angle is typically 90-, 60- or 45-degrees, and the smaller the angle of engagement, the larger the feed. 

We ask our customers to do the average chip thickness calculations because we know it will improve their productivity and tool life. If you have any questions about these calculations, please don't hesitate to contact me.

About the Author

Todd is the manager of rotating products for NAFTA, responsible for solutions and applications involving face, square shoulder and disc milling. Todd and his team of product experts are dedicated to providing a consistent, high-level of support to Seco customers throughout the United States, Canada and Mexico. In his spare time, Todd likes to bowl and cheer on the University of Michigan football team.