There is still room to maximize ceramic indexable tooling. “Unless we are running on state-of-the-art, purpose-built, latest generation machines, we are limited by the rigidity, dynamics or power when applying ceramic indexable tools. In an ideal environment we are able to turn Inconel 718 at 1,476 sfm (450 m/min) with WG-300, or at 820 sfm (250 m/min) with XSYTIN-1, but with a very heavy chip,” according to the team.

For deep-hole applications (>8xD), Iscar has also added double-margin drilling heads as well as inserts designed with self-centering, chip-splitting and flat-bottom geometries. In the DR-Twist line (four cutting edge inserts), there are geometries for general applications (medium to high feeds), soft materials (low to medium feeds) long-chipping materials (added chipbreakers) and aluminum (ground sharp edge, polished face).

Step that prepares a slug, blank or other workpiece for machining or other processing by separating it from the original stock. Performed on lathes, chucking machines, automatic screw machines and other turning machines. Also performed on milling machines, machining centers with slitting saws and sawing machines with cold (circular) saws, hacksaws, bandsaws or abrasive cutoff saws. See saw, sawing machine; turning.

Pollock said that there are some machines and applica-tions where the machines can push the capability of the tools in aluminum machining. “But I think the more common point is that modern cutting tools allow machines to do more. Carbide substrates and free-cutting geometry increase the capability of smaller machines to process a wider variety of materials and large parts,” he said.

“To be fair, there are other uncertainties that could be contributing to instability—lack of rigidity and vibration dampening in the fixture, for example,” according to the team. “Comparatively few machines are also equipped with high-pressure coolant, which is extremely beneficial in the rough- and medium-turning of heat-resistant superalloys in that it greatly improves chip management (and to some extent also improves the dissipation of heat from the tool).”

In recent years, Iscar Metals Inc., Arlington, Texas, has made performance improvements by adjusting the alloying elements in tungsten carbide substrates, using new combinations of various coating layers and applying post-coating treatments. Iscar has also developed different edge prep geometries for a variety of material group applications.

No one can accuse cutting tool manufacturers of not trying every possible combination of coating, substrate, material and geometry in their quest to gain a competitive edge for their customers.

Within its milling family of products, Seco Tools is launching a double-sided face mill called the Double Quattromill 14, building on the success of its Double Quattromill 22 face mill for roughing and semi-finishing introduced at IMTS 2018 for heavy DOC machining.

“We are integrating the same positive cutting action and effective cutting rake angles of our single-sided insert cutters into our double-sided insert cutters. Incorporating the geometry of the single-side, four-edge square type insert into double-sided inserts allows you to get free cutting action and economy,” he said.

According to Ewing, Iscar now offers indexable head drills from 0.157 -1.575″ (4.0-40.0 mm) dia. Most of that range is offered in 0.004″ (0.10 mm) increments. Drill bodies are offered in 1.5xD, 3xD, 5xD, 8xD and 12xD drilling depths with some bodies offering chamfer collars for combined operations. In addition, standard tooling designs are also being incorporated into special tool applications to increase productivity in medium to large quantity part runs. The special tool is often more expensive than a standard tool, but because it utilizes standard indexable carbide inserts the consumable costs can be greatly reduced.

When it comes to performance of indexable cutting tools compared with brazed PCD, CBN and carbide tip tooling, “it’s a question of cost and application,” Winter said. “Anytime you can use an indexable tool, the cost will be lower. The performance is in the cutting material (PCD, CBN, or carbide) and it’s a matter of if the tool can fit into the application.”

Seco Tools LLC, Troy, Mich., has developed advanced coatings such as a Niobium PVD thin coating for machining titanium and plans further advances in its Duratomic aluminum oxide-based CVD coating for general types of steel and cast-iron machining.

Process of both external (e.g., thread milling) and internal (e.g., tapping, thread milling) cutting, turning and rolling of threads into particular material. Standardized specifications are available to determine the desired results of the threading process. Numerous thread-series designations are written for specific applications. Threading often is performed on a lathe. Specifications such as thread height are critical in determining the strength of the threads. The material used is taken into consideration in determining the expected results of any particular application for that threaded piece. In external threading, a calculated depth is required as well as a particular angle to the cut. To perform internal threading, the exact diameter to bore the hole is critical before threading. The threads are distinguished from one another by the amount of tolerance and/or allowance that is specified. See turning.

Hertel has historically offered a full line of general turning inserts in common geometries, sizes and multiple grades. Its portfolio includes high-speed steel, cobalt and carbide drills in a variety of lengths, such as jobber, screw machine and taper. Threading products are available in general purpose hand, spiral point and spiral fluted taps with taper, plug or bottoming chamfers. Hertel offers a full line of general purpose end mills, including roughing, ball nose, square end, 2-flute, 3-flute, multi-flute and double-ended products.

Indexable cutting tools are being used for innovative applications. “The biggest advancement for indexable tooling is in the application of those tools,” said Winter. “We are getting away from the ISO standard and pushing the limits of both tools and machines with creative designs. PrimeTurning is a perfect example of this. Using multi-directional turning, we see big gains in productivity and tool life. It used to be that ISO milling was the popular choice but now you would be hard pressed to find ISO milling in shops. By looking outside of ISO turning, we can push the tools, machines and the limits of the carbide inserts.”

Winter said that the latest developments for indexable milling, turning and drilling tools are more application-specific tools designed to perform a set operation at the highest level of performance. The processes will be optimized to maximize the machine tool, workholding and the tooling for a set application or component.

Greenleaf Corp., Saegertown, Pa., is continually working to develop improvements in geometries to match the capabilities of its ceramic and carbide grades. The following is based on a written assessment of product and technology advances provided by the Greenleaf Applications Engineering Team.

• More than 250 new Hertel spotting drills and combined drill and countersink tools join the hole-making tool line. With 60ÌÜÅÁ, 90ÌÜÅÁ and 120ÌÜÅÁ point geometries, the HSS and cobalt tools can meet a wide range of application requirements.

“These features have contributed to increases in operating parameters and tool life and resulted in innovations in indexable tools for holemaking,” said Craig Ewing, national product specialist-drilling for Iscar.

• A threading solution adds to MSC's cut-off and grooving system, increasing its flexibility and effectiveness. The system incorporates various combinations of inserts, blades and monoblock tool holders that enable tooling to be exactly tailored to specific production needs. Customers can select from material-specific grades to drive the most productivity in various work piece materials.

“By pairing our patented Excelerator ball nose insert geometry with our WG-600 and XSYTIN-1 grades, we provide customers with the ability to mill hardened and difficult-to-machine materials with a full-radius ceramic indexable tool. Our Excelerator ball nose inserts with patented geometry offer better performance, longer tool life and superior cutting action across a wide variety of materials.”

Improvements in indexable cutting tools extend to virtually every cutting process. Until the day when it will be sufficient to establish a baseline for comparative and competitive tooling performance through data analytics (a distinct future possibility of digitization and the IIoT), cutting tool manufacturers will rely on tried-and-true processes.

“New indexable cutting tools often require faster spindle speeds, increased feed rates and multi-axis capabilities that today’s modern CNC machines are capable of to maximize their performance,” said Ewing. “For example, a 0.157″ [4[4-mm]umoCham drill can run above 11,000 rpm and up to 40 ipm [1[1 m/min]n mild steel. Even at the low end, you need more than 6,000 rpm for this tool. Some machines from 10-15 years ago would not be able to properly run this tool.

"We are constantly looking for opportunities to bring new solutions to market that will not only meet our customers' needs, but help them optimize their businesses," said Brian McGrath, MSC's Senior Product Manager for Hertel. "We recognized the need for more enhanced lines of Hertel tooling in response to our customers evolving needs. Hertel is synonymous with performance, increased productivity, cost control and profitability, and it was our goal to give them more selection to achieve their business goals."

Tool that cuts a sloped depression at the top of a hole to permit a screw head or other object to rest flush with the surface of the workpiece.

Another material that has not been an application area for ceramic indexable tooling is stainless steel. Duplex, 300 series and precipitation hardening steels are now being machined effectively with Greenleaf’s whisker-reinforced ceramics, according to the company.

Winter pointed to Sandvik Coromant’s CoroPlus digital machining system as an example. “With the use of CoroPlus, you can use machine analytics to see exactly where you can make improvements to maximize your production. CoroPlus is data-driven process control that will push the tools and machines to the highest level of productivity possible with modern tooling,” he said.

They will mix and match data about chemical makeup, substrates, geometry and machine capability to advance technology the old-fashioned way—by R&D expertise, trial and error, internal testing and validation of new concepts in the field. Here’s how major cutting tool manufacturers are advancing the technology of indexable cutting tools.

Maximizing indexable cutting tool performance depends on whether or not operators are pushing their machines to their fullest potential for both tooling and process. “We need to educate our customers on best practices to be more aware of their machine utilization,” he said. “Many shop owners or plant managers can only give you an educated guess of their actual machine utilization and that utilization is sometimes much lower than they think. And on-lights, stopwatches and clipboards are being replaced by machines and tooling with sensors that can give thousands of data points.”

High speeds or high cutting forces amplify even the smallest instabilities in a machine, leading to deflection and, since the process is inherently cyclic, vibration. No matter how tough a ceramic is, vibration leads to irregular mechanical loads that bring about irregular wear that then translates into poor tool life.

Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.

Stainless steels possess high strength, heat resistance, excellent workability and erosion resistance. Four general classes have been developed to cover a range of mechanical and physical properties for particular applications. The four classes are: the austenitic types of the chromium-nickel-manganese 200 series and the chromium-nickel 300 series; the martensitic types of the chromium, hardenable 400 series; the chromium, nonhardenable 400-series ferritic types; and the precipitation-hardening type of chromium-nickel alloys with additional elements that are hardenable by solution treating and aging.

WG-600, a coated whisker-reinforced ceramic, in particular is showing “outstanding performance in turning. Finally, applications where even large-grain carbide lacks toughness (heavy interruption, impurities, forging scale) can now be addressed with XSYTIN-1 where other ceramic and carbide tools break.”

Any manufacturing process in which metal is processed or machined such that the workpiece is given a new shape. Broadly defined, the term includes processes such as design and layout, heat-treating, material handling and inspection.

“Current insert substrates and pressing technology allow for free-cutting positive geometry that doesn’t easily chip,” he said. “Positive geometry can even be added to inserts with negative basic shape or even tangentially mounted inserts.”

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Machining grooves and shallow channels. Example: grooving ball-bearing raceways. Typically performed by tools that are capable of light cuts at high feed rates. Imparts high-quality finish.

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Substances having metallic properties and being composed of two or more chemical elements of which at least one is a metal.

MSC Industrial Supply Co. is significantly expanding its Hertel line of metalworking products. This expanded offering features a wide range of new tools, including material-specific turning insert grades, spotting drills, combined drill and countersink tools as well as additional solid carbide roughing end mills. In addition to these enhancements, a threading solution has been added to the company's proprietary cutoff and grooving system to help drive greater efficiencies.

“Indexable tooling exists for almost every type of application: milling, turning and grooving, drilling, slotting, boring, and reaming,” explained Luke Pollock, product manager, Walter USA LLC, Waukesha, Wis. “They all use different styles of inserts designed for the needs of the applications. Typically, indexable tooling is considered larger and therefore stronger, capable of taking higher horsepower cuts and higher material removal rates compared to solid tooling. As a result, indexable tools have become more competitive in applications traditionally dominated by round tools.”

Iscar continues to expand the line of drilling tools with new cutting geometries. In the Sumo-Cham line there are different edge preps for steel (P), stainless steel (M), cast iron (K) and non-ferrous (N) materials.

Indexable tools can be used in almost every application. “We are seeing more use in high-speed aluminum machining,” he said. “Advances in insert geometry and grades, as well as balanced tools and rigid holding of the insert, allow indexable tools to be used at higher rpm and sfm. Aluminum machining can take advantage of high rpm and machine tool builders have been developing spindles to run at these speeds. Traditionally, solid tools would have to be used in these applications due to balance and rigidity.”

For drilling, along with the SumoCham and DR-Twist lines, Iscar offers the LogIQ-3-Cham, Cham-IQ Drill, Combi-Cham and Modu-Drill, as well as solid-carbide drills. The LogIQ-3-Cham three-flute drill offers higher feed rates due to the extra flute and creates more accurate holes in terms of diameter tolerance and roundness. The Modu-Drill series [1.299-1.575" (33-40 mm)] has interchangeable heads for different sizes and styles (Cham-IQ Drill, Combi-Cham and DR-DH).

“Time is money. By pushing the machines and the machines pushing the tooling, we can meet the needs of our customers and help save time and be more profitable,” Winter explained.

“We’re seeing a split in the market, a split where the indexables are being used for roughing and solid-carbide end mills do the finishing, especially as production components are becoming more near-net shape,” said Todd Miller, product marketing manager. “There is an equal need for indexables today as there is for solid tools.”

Cutting tool improvements range from some actual grades that are being refined with additives in the substrate for better wet or dry machining to product upgrades. Improvements to Seco’s Perfomax indexable insert drill, for example, include an improved, highly polished body with wave pattern technology for chip evacuation, increased hardness for wear resistance and elimination of coating altogether.

Improvement in indexable tooling requires a holistic approach, according to John Winter, product management-East U.S. for toolmaker Sandvik Coromant, Fair Lawn, N.J. “We are pushing every aspect of the process to produce the best cutting tool solution possible, from coating technology to the macro and micro geometries that produce a stronger edge line to the post-treatment processes that give the coatings a harder, smoother surface.”

“In turning, everybody has the same ISO standard toolholders so it’s technology like our Steadyline anti-vibration holders, Jet Stream tooling holders and second generation Duratomic coating that makes a big difference,” said Miller. “In milling, there have been many technological advancements as well as process improvements. Today, processes like dynamic milling require high-tech tools that take a full axial DOC and a light radial DOC at an extremely high feed rate.”

• Hertel turning insert products, including HC115T turning grade for steel, HP410T/HT410T grades for nonferrous materials, and HP510T grade for high temperature alloys. The new grades are available in a comprehensive selection of insert shapes and chip control geometries for fine finishing, medium, and roughing applications. In addition we've also added our next generation of insert grades which include HC1250T, HP225T, HC405T and HC315T. These new grades and chip breaker geometries work across a wide variety of applications, including steel, stainless steels and cast iron.

Available in two major types: tungsten high-speed steels (designated by letter T having tungsten as the principal alloying element) and molybdenum high-speed steels (designated by letter M having molybdenum as the principal alloying element). The type T high-speed steels containing cobalt have higher wear resistance and greater red (hot) hardness, withstanding cutting temperature up to 1,100º F (590º C). The type T steels are used to fabricate metalcutting tools (milling cutters, drills, reamers and taps), woodworking tools, various types of punches and dies, ball and roller bearings. The type M steels are used for cutting tools and various types of dies.

Positive cutting geometry can maintain acceptable, if not increased, tool life and allows for lower horsepower cuts and less torque on the machines, according to Pollock. However, this can create a weak cutting edge.

For deep-hole applications, Iscar offers a line of BTA drills in single-tube and double-tube variations; indexable gun-drills including the Sumo-Gun and Tri-Deep; and standard gundrills. Indexable reaming tools include the Bayo-T-Ream, Index-H-Ream, and Solid-H-Ream.

“Today’s mill-turn machine offerings make it easy to combine many operations into one setup that often had to be done in multiple setups in the past. Iscar offers indexable tooling solutions that take advantage of these machine capabilities, such as multi-function tools for turning, facing and threading operations.”

Whisker-reinforced ceramics have sufficient hardness (and more than sufficient toughness) to machine most of the materials where carbide tools lack hardness and CBN lacks toughness. In addition, the tooling costs associated with indexable ceramics are significantly lower per cutting edge than they are for CBN.

• HertelNotch is the new comprehensive grooving and threading platform which includes inserts, tool holders and spare parts, all designed to cover a wide range of materials.

• Added versions of workhorse M42 cobalt roughing end mills include new sizes, coatings and fine and coarse roughing geometries.

One example is boring a large bore where an indexable boring bar will fit vs. using a small bore where only a brazed tipped bar can fit. The same is true of milling and drilling. “Here you can find advancements with PCD-veined tools versus brazed tools where the PCD is pressed into the tool not brazed,” he said. “This allows us to shape the PCD to the mill or drill tip, giving these tools better performance.”

Greenleaf’s latest advance and newest offering is the phase-toughened XSYTIN-1 ceramic which has “unprecedented edge strength, transverse rupture strength (the ability to support large forces, i.e. heavy chip flow), thermal shock resistance and toughness. XSYTIN-1 is also the most versatile ceramic in Greenleaf’s portfolio, successfully machining soft mild steel, weld-overlaid cobalt-based alloys and anything in between,” according to the Greenleaf team.

Brazed tooling is generally considered to have tighter tolerances since the assembled tool can be finished (ground and polished). These harder materials in brazed form are usually limited in the cutting geometry that can be used in the tool design. Indexable inserts have the opportunity of geometry pressed into the insert so that different machining applications can be handled simply by using a different insert with different geometry or grade.