Wednesday, June 24, 2015

Are You In Over Your Head With Deep Hole Drilling?


By Manfred Lenz, Product Manager – Drilling

Seco Feedmax SD230A deep hole drills
Machinists often find deep hole drilling – at depths from 12 to 30 times drill diameter – daunting. Many are unsure about the process along with all that is required to maintain good hole straightness, tolerance/size and surface finish. Fortunately, there are some simple tips that will allow machinists to achieve near-perfect deep drilled holes while also increasing productivity as well as tool life.

1. Match pilot drill diameter.
When deep hole drilling, a machinist must first produce a pilot hole, typically at a depth of 2 to 3 times the pilot drill diameter. Pilot holes should be the same size diameter as the deep hole drill to be used. This matching hole size creates a starting point and helps guide – almost like a bushing – the long drill, keeping it straight and preventing it from walking. Without a pilot hole at all, the long drill would vibrate back and forth at the start of the hole and eventually break.

2. Switch off the spindle when entering the hole.
A very common mistake machinists make is to feed an already rotating deep hole drill into a pilot hole. This causes the long drill to slap the sides of the hole, decreasing the tool’s life. Instead, leave the spindle off, fast feed the drill into the hole, then turn on the spindle when the drill tip is about 0.020" (0.5 mm) above where the pilot hole ends and begin to drill without pecking

Rapid feeding drills out of deep holes is a mistake as well. At the end of the drilling depth, the machinist should reduce the spindle speed to a few hundred rpms and retract the deep hole drill at a slow rapid to where drilling started. At that point, the machine spindle is switched off, and the drill exits the remainder of the hole.

Stopping a drill’s rotation before it enters a hole, retracting it slowly and at reduced rpms can increase drilling cycle times, but by barely a fraction of a second. The resulting gains in tool life far outweigh that little amount of added time.

3. Pay attention to drill geometry.
Drill geometry is a key factor in successful deep hole drilling. Pilot drills, for instance, can have 140-degree point angles, while long drills may have 136-degree point angles. This ensures that the center of the long drill will contact the material first while in the pilot hole and seat itself. Then, the corners make contact.

Some deep hole drills also have two land margins per flute. The drill tip does the cutting, while the land margins at the sides help hold the drill in place during operation. On long drills, land margins are located only at the very ends of the flutes for clearance that prevents drag. The more flute drag, the more heat generated and the higher the risk of drill breakage.

Solid-carbide drills are a must for producing hole depths greater than 12 times the drill diameter. Carbide tools are stiffer and less likely to wander as compared with HSS and cobalt tools in deep hole drilling. However, deep holes with large diameters – 3” or more –, will require the use of insertable deep hole drills.

4. Ensure proper chip evacuation.
The number one reason drills fail is due to inadequate chip evacuation. While most long drill geometries provide affective chip breaking, they must then efficiently evacuate the chips out of the hole. Those drills with both polished flutes and back tapers will work best.

Coatings minimize frictional heating and thus contribute to increased tool life. Coolant, however, is the most important factor for chip evacuation. Even one chip left in the hole can break the drill, so high-pressure through-tool coolant is the only option. High-pressure coolant forces them up the drill flutes and out of the hole. Through-coolant drills also eliminate the need for pecking cycles.

5. Use the right toolholder.
Hydraulic and shrink-fit toolholder systems generate the least amount of runout, making them ideal for deep hole drilling applications. Both systems can cost a bit more, and precision collet chucks are one alternative. But they must be high quality and provide very low runout.

A final and very important tip is to consult a tooling expert. A partnership between a shop and its tool supplier makes all the difference in choosing the right drill for deep holes, or any holes for that matter.

About the Author
Manfred has been with Seco for more than 16 years. In his current role as drilling product manager, he is responsible for every aspect of the company’s drilling products in North America. He works closely with global R&D on new innovations to ensure they meet the market’s tough manufacturing demands. Manfred also supports the Seco sales force by providing them with technical information and cost saving solutions that bring value to customers. In his spare time, he enjoys boating, bowling and golfing.

Monday, April 27, 2015

3 New Ways to Maximize Your Steel-Turning Operations

By Chad Miller, Product Manager –Turning and Advanced Materials

When a new insert grade comes to market, it typically reflects a compromise between impact and wear resistance – toughness and hardness. The reason being is that cutting tool companies often develop grades to maximize performance in specific manufacturing conditions, but a grade made for one situation can prove less productive in another. 

For example, manufacturers that want to machine at fast cutting speeds usually choose an insert grade with high hardness and heat resistance, but these tools often break in interrupted cuts. And on the flip side, a tougher tool lacks the heat resistance necessary to withstand the elevated temperatures generated in high-speed machining.

There is, however, three new ways for shops focused on steel-turning applications to overcome this common conundrum: TP2501, TP1501 and TP0501. These three new insert grades, which feature our next-generation Duratomic® technology, achieve the elusive balance of toughness and hardness when machining steel alloys, stainless steels and even cast iron.

Plus, the application areas for our latest TP grades overlap to cover every possible steel-turning need, whether the goal is versatile, balanced or high-speed productivity. And as machining challenges continue to change, these grades provide shops with options.      

TP2501, for example, is the tougher, general-application grade of the trio. It provides the broadest working range and is a good starting point for those processing short runs of parts in various steel alloys. The operations may include rough machining and some interrupted cuts. The toughness of the grade permits with- or without-coolant application. Overall, the focus of the TP2501 grade is on reliably completing jobs and not so much optimizing operations for maximum output.

For higher-production situations where there’s time to optimize the machining parameters, the TP1501 grade provides a higher hardness for increased cutting speeds. Typical applications would be in the automotive industry, where a combination of maximum parts-per-hour production and solid reliability are goals. Because of the grade’s higher hardness and maximized edge toughness, it brings enhanced wear and deformation resistance in low-to-medium temperature, semi-interrupted cutting conditions. Coolant use with TP1501 is optional.

Engineered to perform well in turning operations that generate high temperatures, such as long, continuous passes at heavy depths of cut, the heat-resistant TP0501 grade can be run without coolant in many situations. A balance of high edge hardness and toughness boosts the wear resistance of TP0501 inserts, especially for more stable high-temperature, continuous cutting conditions. TP0501 is made to cut all types of steels, with a particular emphasis on high-alloy workpiece materials.

Overall, these new TP grades provide the often-unachievable balance of hardness and toughness to truly optimize machining operations. And in combination, they represent an integrated, efficient solution for steel-turning operations industry-wide.

If you have questions about these new TP grades, please don’t hesitate to contact me. You can also sample one of these new grades for free by visiting freeduratomic.com and answering a few basic questions about your steel-turning application.

About the Author  

Chad manages Seco's turning and 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.  

Wednesday, April 1, 2015

New Duratomic

Guest blog by Peter Zelinski, Writer and Editor for Modern Machine Shop


Chrome is the New Black
Certain products succeed long enough that the product brand acquires its own cachet apart from the originating company name. In certain circles, Seco’s “Duratomic” is like that. The toughness and wear-resistance of this cutting tool coating have made it successful in steel machining applications such as the one portrayed in this video. When the coating was introduced in 2007, Seco says it represented the first time a coating had been manipulated on the atomic level. And in few days, the company says, Duratomic will be introduced again.
Launching April 1, a complete overhaul to the Duratomic line will improve upon the previous successful coating with new coating technology delivering 20 percent greater life across most of the tool’s applications, including heavy, low-speed turning applications that are commonplace among oilfield manufacturers that have applied this tooling in growing numbers in recent years.
Another important feature to be introduced is “edge intelligence,” the company says. The dark color of Duratomic inserts has made edge wear difficult to see. This has been a challenge in high-volume facilities that change inserts frequently, because inserts with unused edges sometimes get discarded. The new Duratomic addresses this challenge with a multilayer system that the company says makes tool wear easy to visually gage.
Learn more by visiting the Duratomic site, which includes a countdown clock ticking the moments until the line’s relaunch.
Check out the original blog post from March 26, 2015, on mmsonline.com. 
About the Author
Peter Zelinski has been a writer and editor for Modern Machine Shop for more than a decade. One of the aspects of this work that he enjoys the most is visiting machining facilities to learn about the manufacturing technology, systems and strategies they have adopted, and the successes they’ve realized as a result. Pete earned his degree in mechanical engineering from the University of Cincinnati, and he first learned about machining by running and programming machine tools in a metalworking laboratory within GE Aircraft Engines.

Thursday, February 19, 2015

Tools & Strategies for Machining ISO-S Materials in Aerospace

By Scott Causey, International Aerospace Specialist 

Jabro JHP770 and 780
Manufacture of precision components in the aerospace industry requires innovative engineering and technology, especially when machining with newer, high-performance workpiece materials. Today’s ISO-S alloys, namely nickel-, cobalt- and iron-based heat resistant superalloys (HRSA), and titaniums have many beneficial properties that make them great choices for a wide range of crucial applications. At the same time, some of their characteristics make these materials challenging to machine.

ISO-S alloys provide higher resistance to heat and wear, extreme toughness, and unwavering quality and reliability. On the flip side, they have low thermal conductivity, which reduces tool life and causes part distortion. They have tendencies to strain and precipitation harden when machined, which increases cutting forces and further degrades tool life, and the sticky behavior of these alloys creates uncontrolled built-up edge (BUE) and notch wear. Using advanced tools and application strategies can help you maximize the benefits and address the difficulties of machining these alloys. 
  • Match the cutter to your desired profile. Application of ISO-S materials is common in aerospace turbine blade production. Seco offers a fir tree cutter with spiral fluting to machine the specialized profile of the blades, which has extremely tight tolerances. The Jabro® fir tree provides a smooth, easy cutting action with an advanced cutter geometry that prolongs tool life and offers unmatched accuracy.
  • Limit cutting speeds when cutting titanium alloys. Structural aerospace parts, such as landing gear components, are massive and strong. When manufactured from standard materials, they are also very heavy. Today, manufacturers are using newer, lighter and stronger titanium alloys to produce lighter landing gears, but these new materials are more difficult to machine. One newer alloy is titanium 5553, which includes 5 percent aluminium, 5 percent molybdenum, 5 percent vanadium, and 3 percent chromium content. Its benefit is high tensile strength: 1160 MPa compared to 910 MPa for Ti6Al4V, but this higher tensile strength requires limiting cutting speeds to levels 50 percent of the speeds applied with Ti6Al4V.
  • Apply parameters for most-difficult-to-machine material when cutting stacked alloys. Some aerospace applications involve machining components composed of stacks of differing materials. An example is an engine mount featuring a titanium 6Al4V/austentic stainless steel stack. Both materials share some properties including relatively high strength and adhesive properties that cause the cut material to stick to the endmill, and the challenge is to machine the “sandwich” or “hybrid” with adequate chip control and no vibration or burrs.
Seco’s carbide Jabro JHP 770 tool designed for machining titanium is a good solution. This tool incorporates differential flute spacing, radial relief, a specially formed chip space, and a through-coolant channel that minimizes workpiece adhesion and clears chips.

In machining the stacked materials, the key is to apply the parameters for the more difficult-to-machine material. In this example, keep in mind the titanium’s low thermal conductivity. We recommend using a moderate cutting speed of 50 m/min, with a feed of 0.036mm/rev feed, and a 3 mm depth of cut, descending in circular interpolation. 
  • High-Speed Steel (HHS) cutters are a productive and cost-effective choice. Many large aerospace components, such as landing gear parts, are machined from solid billets of titanium or stainless steel. For these parts, high-performance HSS tools up to 50 mm in diameter are capable of removing large volumes of material. The HSS tools are very effective on low-rpm, high-torque machines for effective roughing and even finishing of titaniums and stainless steel. The ability to use large diameters and widths of cut enables the tools to provide competitive metal removal rates even when run at lower speeds than those achievable with carbide tools. 
An example of an advanced HSS tool is the Jabro JCO710 HSS-Co cutter with 8 percent cobalt content and a hardness of 67 HRC. The tool features polished flutes to reduce friction and edge build-up, and a variable face profile geometry to cut light and reduce the risk of chatter that causes unacceptable surface roughness values. We have seen these cutters provide more than 800 minutes of tool life when applied at a manufacturer producing large titanium parts. 

The goals of aerospace parts production are top quality, reliable consistency and productivity. As metal producers develop new alloys to meet increasingly demanding high-performance applications, we are engineering new cutting tools and strategies to enable aerospace manufacturers to overcome the challenges of machining these materials. Please contact me to learn more.
About the Author 
As Seco’s International Aerospace Specialist, Scott is responsible for supporting the company’s aerospace segment customers, which includes optimizing current processes and defining new technologies. In his spare time, he enjoys spending time with his family and working with horses. 

Monday, February 2, 2015

Balance Cutting Tool Life With Productivity

By Chad Miller, Product Manager – Turning and Advanced Materials

When it comes to cutting tools, machinists often find themselves torn between maximizing tool life and increasing productivity. But it really doesn’t have to be a choice. By understanding and following a few basic rules, it’s possible to achieve a balance of long life and high productivity from the same cutting tool.

1.  Tweak speed slowly within the recommended range.
Speed is the single biggest factor affecting cutting tool life – the higher the speed, the lower the tool life.  Unfortunately, machinists looking to increase productivity often make the common mistake of just cranking up the speed. They may even turn on the machine override and start running at speeds that are 20 or 30 percent higher. While this may increase the number of parts produced, it will drastically reduce the tool life. In fact, we’ve seen that increasing the speed by 50 percent can cause tool life to go down by as much as 90 percent. It’s best to stick within the tool’s recommended range for cutting speeds, tweaking speeds carefully along the way to find the best maximum that gives you both longer tool life and a higher level of productivity.

2.  Increase depth of cut to improve cutting tool productivity.
Increasing depth of cut can have an enormous impact on productivity. At the same time, a larger depth of cut does not have much effect on cutting tool life.  When machining a component that will have numerous passes with an insert, increase the depth of cut to reduce the number of passes thereby increasing productivity. 

3.  Increase feed rate to get more productivity out of the same inserts.
When it’s not possible to decrease the number of passes by increasing the depth of cut, the next best thing is to consider increasing the feed rate. When I am with a customer on his or her shop floor, the first thing I look at is how to increase feed rate without sacrificing surface finish. If we can increase the feed rate and still achieve the desired quality and precision, we can reduce processing time.

4.  Take a closer look.
One of the best ways to find the balance between the variables affecting tool life and productivity is to study how the tool is behaving during operation. Let’s say you’re currently getting about 100 parts per edge and you want to increase productivity to 125 per edge. Stop machining and pull the tool after about 80 pieces or 80 percent of the tool life and look at the edge wear under high magnification. This closer inspection will give you a good idea of what is going on with that insert – its condition or changes that have occurred– and allow you to adjust speed, feed or possibly change to a different grade or chip breaker to be able to increase throughput.

5.  Choose the strongest insert geometry.
Using the strongest possible insert geometry for the application gives you an opportunity to increase productivity by pushing feed rate and depth of cut. According to ISO standards, round insert geometries are going to be the strongest, followed by square, C, P and then V, respectively.

Machinists in different industries view the importance of tool life compared with productivity differently. Machinists in the automotive industry, for example, are often more concerned with achieving a higher volume. They need to get a lot of parts through the door very quickly and tend to run the inserts a bit faster in feed and speed. 

On the flip side, machinists in the aerospace industry are generally more concerned with tool life and quality. When machining high precision parts such as jet engine components, they want to make sure the insert completes the part. They absolutely do not want to have to pull the insert out in the middle of machining, so we see them running at more conservative speeds to extend the life of the tool.  

The most important tip of all is to use the insert within the recommended guidelines for speed and feed. Following these recommendations should result in good tool life. To learn more about how to balance tool life with productivity or discuss a specific challenge, please feel free to contact me.

About the Author
Chad manages Seco's turning and 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. 



Friday, January 2, 2015

2 Key Components Truly Optimize Machine Utilization

By Manfred Lenz, Manager – Drilling Products, NAFTA

Maximum productivity and profitability in machining operations hinge on two key components of machine tool utilization. The first is to maximize the amount of time the machine is available to actually cut metal. The second, which is often neglected, is to then make the most productive use of that time. 


Maximize available time
Machines are on the shop floor 8,760 hours (365 days) a year, but their productive availability is much less than that. For instance, a year of five-day, single-shift workweeks, and taking into account time lost to holidays and other interruptions, equates to approximately 1,300 or 1,400 hours of actual available machine time. However, programming and setup further consume a portion of that time.


To shorten a machine’s non-cut time as much as possible:

• Use strategies such as offline programming and modular setups 
• Streamline tool handling with tool magazines and automatic tool changers
• Quickly load and unload workpieces with robotic work handling and/or pallet changers 

Make efficient use of time 
Once available to cut time is maximized, manufacturers must use that time efficiently, which means to produce as many parts as possible and at the lowest cost. To accomplish this, machines, while in the cut, should run at their full potential/capabilities but without exceeding safe limitations. 

Average Time Spendings on a Machine Tool 
Keep in mind that some elements of the machining process are unchangeable. A component’s final application determines the raw material from which it’s made, and the material’s machinability, in turn, dictates basic cutting parameters. For example, the poor thermal conductivity of titanium alloys requires that machines run at lower cutting speeds and feedrates to minimize heat buildup. 

Machine tool capabilities are also a given, because changing the machine is rarely an immediate option. Manufacturers recognize these factors when estimating production costs. However, significant differences between estimated and actual costs can result from inaccurate evaluation of machine tool characteristics and the application of cutting parameters that are impossible to sustain. 

There are some common strategies applicable to all machining operations for establishing initial cutting parameters that will contribute to efficient machine use.

• Select cutting tools with substrate material, coatings and edge geometries that are best suited for the workpiece materials and intended machining operations.

• Apply the tool’s recommended minimum cutting speeds to prevent tool breakage, ensure proper chip formation and limit heat generation.

• Increase feedrates and depths of cut as high as possible without compromising workpiece surface finish.

• Recognize the power and stability characteristics of the machine tool.

By concentrating on maximizing machine tool availability and making the most of that time, you can increase both productivity and profitability in your machining operations. For more ideas on how to effectively manage your tools, please feel free to contact me.  

About the Author
Manfred has been with Seco for more than 16 years. In his current role as drilling product manager, he is responsible for every aspect of the company’s drilling products in North America. He works closely with global R&D on new innovations to ensure they meet the market’s tough manufacturing demands. Manfred also supports the Seco sales force by providing them with technical information and cost saving solutions that bring value to customers. In his spare time, he enjoys boating, bowling and golfing.