One solution is by applying a power cut machining strategy, which has emerged as a highly effective approach for roughing operations. Such a strategy ensures efficient metal removal rates and excellent process security. With an effective power cut strategy, manufacturers can optimize roughing operations, boosting productivity and reducing cycle times.

However, tools designed for larger engagements are necessary to achieve this. That is why Sandvik Coromant’s engineers sought to develop an optimized and effective solid carbide end mill that would excel in this area. The result was CoroMill Plura HD and now the next generation is launched with two new grades.

In conclusion, Sandvik Coromant's CoroMill Plura HD solid carbide end mill is a strong performing tool that brings large performance improvements also in less favorable operations. The end mill contributes to large improvements both in tool life and in productivity versus competing tools. With its Zertivo 2.0 coating, the product family improves process security, tool life and productivity versus old generation grades and competing tools.

CoroMill Plura HD is offered in two different grades and coatings, and both have been upgraded. One of the new grades is P2BM for steel; the other new grade is M2CM for stainless. The larger radial engagement allows for higher material removal rates (MRR) than HFS in applications, and this advantage can be achieved up to 2xDC The result? Increased material removal in a single pass.

CoroMill Plura HD and Zertivo™ 2.0 were assessed in extensive performance tests against competitor’s solid carbide end mills

Before we look at the power cut strategy, let’s briefly examine two conventional options for roughing. First, there is the picture frame strategy, an old roughing strategy with an inefficient tool path. Benefits of a picture frame strategy include not needing to update NC programs and that the programs are small, which is beneficial for old machines with limited memory and processing capabilities.

Overall, the Sandvik Coromant tool was found to achieve a 30% improved tool life and 30% improved productivity, at the same time. This was achieved both for the new stainless steel tools in ISO-M machining and for the steel tools in ISO-P machining. It should be noted that these results were accomplished without applying strategy improvements, such as a power cut strategy that would optimize the performance even further

But how should a power cut strategy be applied? Put simply, the method is similar to high feed side milling (HFSM) but with a larger radial width of cut, still benefiting from a controlled engagement and tool load. To be performed successfully, the method entails a constant high radial engagement and smooth motions during machining — both of which contribute towards enhanced process security, tool life and productivity.

Disadvantages include not being able to utilise the full potential of the cutting tool on the “easy parts” of the tool path, and overloading the cutting tool — in the corners, for example. The result is poor from all aspects of machining performance (tool life, productivity, process security, quality of the machined part and machine tool wear/maintenance).

That said, CoroMill Plura HD’s performance can be lifted even higher by applying a power cut strategy. This can improve process security, tool life and productivity even further. By adding a power cut strategy, CoroMill Plura HD’s performance will be multiplied again.

Here, Antti Wikström, global product manager for Solid End Mills — Roughing at Sandvik Coromant, explains how its CoroMill Plura HD solid carbide end mill can overcome these shortcomings, with more predictable and reliable performance.

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For the new grades Sandvik Coromant’s R&D specialists have created new coatings for solid carbide end mills that can improve tool life at the same time as cutting speeds are increased. The new coating technology is called Zertivo 2.0 and offers better resistance to heat and abrasive wear without compromising on toughness. In short, the Zertivo 2.0 coatings contribute by offering a very resilient cutting edge. Both versions of CoroMill Plura HD, the P2BM and M2CM grade variants, use the Zertivo 2.0 technology.

The new tools focus on increased productivity with smart insert locking mechanisms, which, therefore, create a more stable machining process. Iscar has responded to the new market demands that resulted from the trend toward high-speed machining and mill-turn machining centers, with upgrades in both tools and insert geometries, leading to less machine downtime and less labour.

At the Iscar stand, which will emphasise the theme ‘Machining Intelligently’, leading-edge tools will be displayed. These tools help customers adapt to high-speed and high-feed machining, minimum quantity lubrication (MQL) and other modern machining strategies. Iscar continues to expand its existing array of products, which have established many benchmarks in the global metalworking industry.

In today’s economy with tight resources, lean operations and challenging demands, manufacturers need more support from their supply partners. The new innovative tool families, under the IQ Startup campaign, assist the user to increase profitability by employing leading-edge engineering solutions. These new Iscar tools will enable manufacturers to continue to improve their efficiency in metalworking by using modern machining strategies.

Next is the aforementioned HFSM strategy, an efficient and high performing strategy that utilizes the full performance of the tool with high process security and tool life. HSFM tools normally have a very high density of teeth, which is very beneficial for tool life as well as productivity when machining with small radial engagement.

A power cut strategy allows for 70-90% radial engagement, enabling around 10 passes at once compared to a HFSM strategy, since HFSM typically employs a radial engagement of 5-10% of the tool diameter. However, it is worth noting that HFSM can be used with very large axial depth of cuts, whereas the power cut strategy has a limit of two times the cutter diameter for axial depth of cut.

By using the power cut strategy within its working area, which extends up to two-times the cutter diameter, manufacturers can achieve high metal removal rates while maintaining process stability. The controlled engagement and load ensure the stability of the cutting process, reducing the risk of tool breakage or other issues.

One out of many cases where Plura HD has proven its performance is in slot milling a 1.4404 (316L) stainless steel ISO-M component. The M2CM grade CoroMill Plura HD and competitor’s end mill were run at the same machining parameters: a cutting speed (Vc) of 90 m/min, feed per tooth (fz) of 0.05 mm/tooth, radial width of cut (ae) of 10 mm and axial depth of cut (ap) of 5mm. In the end, CoroMill Plura HD exhibited a +65% tool life increase over the competing solid carbide end mill.

The Financial Times has identified inflation and the Ukraine war as major factors that have caused rising energy and raw material prices, including for steel. These escalating costs pose a significant obstacle for manufacturers in terms of achieving a low cost-per-part, and directly impact manufacturers' profitability. How can manufacturers be overcoming these obstacles in their machining applications, while meeting market demands and staying competitive?

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• Dove IQ Turn: An innovative dovetail pocket combined with a lever clamping mechanism provides very firm and rigid insert clamping for heavy turning. • Dove IQ Grip: This line of tools has a unique frontal locking mechanism designed for deep heavy grooving applications with unobstructed chip flow. • Penta IQ Grip: This remarkable design of small pentagonal inserts with five cutting edges is intended for deeper and more accurate grooving and parting applications. • Heli IQ Mill 390: Milling inserts with three cutting edges and advanced cutting geometries function with reduced cutting forces and lower power consumption. This is an economical advantage vs. inserts with two edges. • Dove IQ Mill: Milling insert features a unique design with 8 cutting edges for a wide range of 45o face milling applications, roughing and finishing operations on a wide range of materials. • FlashTurn: A wide range of IsoTurn small size inserts that provide an economical advantage regarding cost per cutting edge. They are available in a wide range of geometries, corner radii, chipformers and the most advanced carbide grades. • Deca IQ Thread: This unique geometry is a 16mm round insert with five double-sided corners that provide 10 cutting corners. The new geometry provides the most economical price per threading corner compared to three cornered laydown inserts. • Do-Grip Jet Line: The coolant stream of the JHP (high-pressure) tools is directed precisely between the insert rake face and the flowing chip. This results in superb chip evacuation which provides extended tool life. • Cham IQ Drill 700: Features a unique design, utilising the carbide flexibility for self-locking, eliminating the need for clamping accessories. Extremely accurate and provides high cylindricity due to an advanced self-centering edge geometry. • SumoCham IQ: Expanded SumoCham drilling head options, featuring a revolutionary drilling head geometry that features concave cutting edges which substantially enhance the self-centering capability of the drill. No pilot hole is necessary. • Sumo Unicham: Drills without a flange, for adjustable protrusion lengths and chamfering operations by using the standard ChamRing modular chamfering drill holders. • SumoGun: Based on the SUMOCHAM insert geometry, for deep drilling applications of a diameter range of 10 to 25.9mm (total length of up to 800mm). SumoGun enables replacement of the drilling head inside the machine – no need to remove the drill for head indexing. • OneTap: A new family of taps that feature an optimised cutting geometry for universal use on all types of materials. • Tang-Grip IQ: Single-ended parting inserts with an unbeatable clamping method featuring a flat blade, thus eliminating chip obstruction. • Swisscut Innoval: Upgraded SwissCut line with new inserts that feature an innovative oval-shaped hole. The new clamping design uses a special screw that can be accessed and operated from both tool sides, preventing the risk of falling parts. • MillShred P290: The ideal solution for machining very high shoulders. The tools and wavy edged inserts reduce chatter and enable optimal machining for a large variety of materials. • Helido 690 Line: New family of tools for 90°milling. The H690 features a triangular insert with six helical right-hand cutting edges. The helical design provides extremely high durability and very stable performance. • SPINJET: Coolant-driven HSM spindles 20 000, 30 000 and 40 000 rpm for small diameter tools.

Machine shops always seek to enhance productivity, improve efficiency, and cut costs driven by market demands and the constant push to stay competitive. Solid carbide end mills for roughing are one solution to these needs, but many existing tools on the market show limitations in performance — both in tool life, productivity and process security.

The performance advantages of CoroMill Plura HD and Zertivo™ 2.0 are especially beneficial for machine shops in all sectors that are looking to manufacture products more easily, efficiently, and cost-effectively. The standard assortment offers diameters from 2–25mm, a 2×D depth of cut, 4 to 5 teeth and a ramping angle of 5° or 7°.

Another example is where the P2BM CoroMill Plura HD end mill was put to work against another competing tool on a SS1672 (C45) 160 HB steel ISO-P component, this time to perform the heavy machining application of dry shoulder milling. The following cutting parameters were used: a Vc of 235 m/min, fez of 0.1 mm/tooth, ae of 7.5 mm and ap of 5mm. In that instance, the P2BM grade CoroMill Plura HD exhibited a tool life increase of +150%.

Small radial engagement also allows for a very high axial depth of cut. However - these tools are not suitable at all for larger radial engagements and, even if they are applied with shorter axial depth of cut, will break. If a Double Depth of Cut (2xDC), or less, is needed then a power cut strategy becomes more efficient.

Iscar strives to work closely with customers, not only to develop new technologies that meet emerging needs, but also to maximise the value of investments in modern machinery by increasing equipment utilisation and optimising performance. Iscar’s IQ STARTUP tools and inserts are well-suited for the new generation of machining centers, enabling high feeds and speeds for highly productive machining operations. These tools are a part of Iscar’s commitment to the ongoing success of its customers.

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