Give threading a whirl - 60 degree carbide insert

Cutting tool material consisting of natural or synthetic diamond crystals bonded together under high pressure at elevated temperatures. PCD is available as a tip brazed to a carbide insert carrier. Used for machining nonferrous alloys and nonmetallic materials at high cutting speeds.

Hole drilling is a commonly performed operation necessary to allow joining of CFRP structures. CFRP drills will have a point geometry distinct to that of metalcutting drills. ANCA’s Toolroom software, whether applied to grinding or PCD erosion processes, allows creation of various special drill points suited to CFRP, including compound point angles and brad or W-point geometry.  Specialized drill points result in minimised delamination as the drill penetrates through the CFRP layer, maintaining hole geometry (roundness) and offering superior tool life.

To complicate matters more, CFRP can be stacked with aluminium or titanium support in structural applications. These conditions create machining operations that need one tool to cut materials with dramatically different properties.

For trimming or edge cuts, up-down cutters are most commonly used. The opposing direction of the cutting edges ensures cutting forces are toward the middle of the CFRP layer, thereby reducing the likelihood of delamination. Shallow flute depth helps increase tool rigidity.

Any machining process used to part metal or other material or give a workpiece a new configuration. Conventionally applies to machining operations in which a cutting tool mechanically removes material in the form of chips; applies to any process in which metal or material is removed to create new shapes. See metalforming.

Another common cutting operation is trimming or cutting of CFRP with specialised milling cutters. Again, coated carbide or PCD cutters are the order of the day.

For the Dragonskin coating, the company not only incorporated the three-layer approach and mechanical post treatments, but it also applied these to indexable insert grades engineered specifically for the intended part material applications. One example is CERATIZIT’s recently released ISO-P steel turning inserts featuring the Dragonskin coating, which extends the working life of the new inserts by as much as 20 percent, when compared to their predecessors.

Robert Bokram is the Product Manager, Cutting Tools, at CERATIZIT, manufacturers of hard material products for wear protection and cutting tools.

Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.

To enhance productivity for its customers CERATIZIT rethought its new CTCP135-P, CTCP125P-P and CTCP115-P turning grades from the substrate to the geometries and through to the Dragonskin coating. This was done to optimize process security and hardness of insert edges to ensure they withstand extreme cutting-zone temperatures without plastic deformation. This also ensures that the inserts handle a full range of machining challenges, such as when materials are extremely hard or tough.

To make matters worse, some shops will continue to push the worn tool to its limit – where it’s likely to fail in the middle of a critical process. While a failed cutting insert is the least of a shop’s problems, damage to the workpiece is the much more significant issue.

The CTCP125-P (ISO P25) universal steel-cutting grade balances toughness and wear-resistance to provide consistent reliability in turning operations, ranging from finishing to rough machining, while the CTC135-P (ISO P35) is a tough carbide grade for lower cutting speeds, interrupted cuts, and unstable machining conditions.

Firstly, composite cutting tools come in one of three different material types. Carbide, coated carbide or PCD. Each has its advantages.

Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.

Permanent (inelastic) distortion of metals under applied stresses that strain the material beyond its elastic limit.

The idea of using fibers embedded in a supporting matrix has been around longer than initially appreciated. From the earliest beginnings of mud bricks reinforced with straw - to the first composite bows made with wood, bone and pine resin - it was recognized that composite materials deliver superior properties than if used in isolation.

Today, ANCA machines are used by cutting tool manufacturers to create a variety of cutting tools for different composite machining applications.

An alternative approach for holemaking is milling cutters used with interpolated orbital motion. While it’s a slower process requiring a CNC machine, it has advantages with creating larger holes or holes on curved surfaces. In addition, the smaller thrust force reduces delamination at the exit point of the hole.

Carbide can be easily fashioned into any required geometry and will produce a keen cutting edge but will also be expected to wear quickly. For that reason, it will typically only get used in manual and/or roughing operations where the accuracy of the final cut is not critical – most likely because it will be followed by a finishing cutter made of either coated carbide or PCD.

Robert Bokram is the Product Manager, Cutting Tools, at CERATIZIT, manufacturers of hard material products for wear protection and cutting tools.

Carbide and high-speed-steel tools coated with thin layers of aluminum oxide, titanium carbide, titanium nitride, hafnium nitride or other compounds. Coating improves a tool’s resistance to wear, allows higher machining speeds and imparts better finishes. See CVD, chemical vapor deposition; PVD, physical vapor deposition.

Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.

Such coatings typically involve multiple layers, the top one of which provides the early-warning wear detection while the others ensure optimum performance and longer tool life. The effectiveness of these coatings, however, also depends on how they are applied. In most instances, special mechanical post-treatments are used and will ensure the layer surface's unique state of residual stress, which then pays off in terms of increased process security, especially in large-scale production operations.

High-temperature (1,000° C or higher), atmosphere-controlled process in which a chemical reaction is induced for the purpose of depositing a coating 2µm to 12µm thick on a tool’s surface. See coated tools; PVD, physical vapor deposition.

Ability of an alloy or material to withstand rust and corrosion. These are properties fostered by nickel and chromium in alloys such as stainless steel.

Compression cutters minimize damage to the CFRP cut edge with cutting forces toward the center of the CFRP layers.

Duncan says: “Machining of these highly abrasive and non-homogenious materials requires careful consideration of the best tool for the job, be it drilling, trimming or pocketing. As a result, cutting tool manufacturers are continually creating new tool designs to meet this need.”

Every cutting insert experiences a drop in performance as it approaches the end of its performance life. If this condition goes undetected for any amount of time, the part-machining performance as well as part quality may have suffered already.

Each of the three grades are engineered for optimizing specific production scenarios. The CTCP115-P (ISO P15) grade has enhanced resistance to elevated temperatures and is ideal for use at higher cutting speeds in smooth, continuous cuts in stable cutting conditions.

Materials composed of different elements, with one element normally embedded in another, held together by a compatible binder.

ANCA grinders support the manufacture of these types of tools with dedicated compression router or burr cutter software packages.

Groove or other tool geometry that breaks chips into small fragments as they come off the workpiece. Designed to prevent chips from becoming so long that they are difficult to control, catch in turning parts and cause safety problems.

The answer to this challenge is typically a solid PCD tip with a carbide body. While these can be expensive up front, RobbJack, based in California, produces such tools using rotary electro erosion process on the ANCA EDGe. This allows complete freedom for producing any tool (drill) geometry they require.

This typically will give a keener cutting edge than CVD coated tools and additionally can be resharpened, which extends the usable life of the tool. Within PCD tools, there are three common forms. First, they can be a carbide base with brazed PCD inserts giving a shear cutting edge. This type of tool is commonly used to produce complex step or profile tools and is most easily produced by tool manufacturers looking to enter the PCD tool market.

Machining operation in which material is removed from the workpiece by a powered abrasive wheel, stone, belt, paste, sheet, compound, slurry, etc. Takes various forms: surface grinding (creates flat and/or squared surfaces); cylindrical grinding (for external cylindrical and tapered shapes, fillets, undercuts, etc.); centerless grinding; chamfering; thread and form grinding; tool and cutter grinding; offhand grinding; lapping and polishing (grinding with extremely fine grits to create ultrasmooth surfaces); honing; and disc grinding.

Cutting tool material consisting of natural or synthetic diamond crystals bonded together under high pressure at elevated temperatures. PCD is available as a tip brazed to a carbide insert carrier. Used for machining nonferrous alloys and nonmetallic materials at high cutting speeds.

The aerospace and defence, wind energy, automotive, civil construction and sporting goods industries have all come to adopt composites for high-performance applications – and the demand continues to grow. A report by Credence Research in 2019 estimated a CAGR of 9.3% for carbon fiber-reinforced plastics during the period 2017-2025. Duncan Thompson, product manager at ANCA, notes the increased sales inquiries in this area, reflecting a growing demand by tool manufacturers to produce cutting tools to service this specialist market.

For surface or pocket milling, down-cut endmills again will create downward cutting forces that minimize surface delamination. Brazed PCD routers are also common for this application with ball or corner radius cutting edge forms, which are easily produced on the ANCA EDGe.

However, if shop managers or operators are able to identify the extent of insert wear quickly and easily, they can replace it in a timely manner and avoid any damage to tools or parts. What makes this possible are advances in cutting tool coatings that, essentially, warn shops of impending insert disasters.

Grooves and spaces in the body of a tool that permit chip removal from, and cutting-fluid application to, the point of cut.

Substance used for grinding, honing, lapping, superfinishing and polishing. Examples include garnet, emery, corundum, silicon carbide, cubic boron nitride and diamond in various grit sizes.

The next alternative is the veined PCD technology, initially developed in house by Sandvik Coromant Spanish Fork. This can create a helical vein of PCD, co-sintered in the carbide blank. The helical cutting edge is seen to offer an enhanced cutting geometry compared to that of a shear tool, and coolant holes can be included through the carbide portion, which improves cutting conditions. For these tools, the cutting edge geometry is largely defined by the PCD vein that was sintered.

The consequences of these types of issues are wasted time and money from tools that rapidly wear out, but more importantly damaged or scrapped work pieces.

PCD insert brazed onto a carbide tool base. EDGe erosion process is used to generate an accurate corner radius profile.

One of the most widely used composite materials is CFRP, principally due to its excellent strength to weight ratio and corrosion resistance. Yet, in machining this material, correct tool selection is critical, otherwise a variety of quality issues can result, including:

“Demand for specialised composite cutting tools will only continue to increase, presenting great market opportunities for tool makers with the right knowhow and manufacturing capabilities. With industry leading tool design software and tool manufacturing machines, ANCA continues to work closely with its customers at the cutting edge of the composite cutting tool market.”

Coated carbide similarly offers flexibility in that it can be ground into a variety of geometries, but has an additional (CVD) coating applied that can dramatically increase tool life. The disadvantage of these tools is that it is generally considered uneconomical to resharpen them.

Burr style routers feature many shallow flutes that have chipbreaker teeth included on them. This form of cutter works to produce localized cutting forces that can effectively shear the fibers.

Today’s composites industry uses a variety of matrix materials, such as thermoset epoxy, phenolic and polyimide,  and fibers, such as carbon, Kevlar and glass, to suit different applications. In a polymer matrix composite material, the matrix itself is not ductile like metal. Instead, it tends to be soft but very tough. Cutting metal involves plastic deformation forming chips that serve to remove heat from the point of cutting. Conversely, when analyzed at the micro level, machining of polymer matrix does not form chips, but rather a fine "dust" that results from localized fracturing. Heat is not readily transported away from the cutting edge by the matrix due to its low thermal conductivity. The next challenge comes from the embedded fibers, which are strong, stiff and highly abrasive when cut. Different composite manufacturing methods call for use of unidirectional tape or bidirectional fabric weave layered in different directions to suit the application. These will behave differently.

Duncan comments: “Commercial applications for composites continues grow, and with that, the market space for specialised cutting tools also expands. Cutting tool manufacturers need to adopt a variety of cutting tool designs and technologies, developing specialized tools for the wide and varied range of composites used today. ANCA has been working with customers to design innovative software that help address these needs, creating new tool geometries, and machines that can grind or erode market leading CFRP cutting tool solutions.

The third class of tools is polycrystalline diamond (PCD) tools. The cutting edge on such tools are typically produced using an electro erosion machine, such as the ANCA EDGe, or laser ablation processes.

Stringy portions of material formed on workpiece edges during machining. Often sharp. Can be removed with hand files, abrasive wheels or belts, wire wheels, abrasive-fiber brushes, waterjet equipment or other methods.

To prevent insert waste and easily detect wear, the gold-colored TiN outer layer of the Dragonskin multilayer CVD Ti(C,N)/Al2O3/TiN coating from cutting tool OEM CERATIZIT, for example, acts as an indicator. It not only enables users to clearly identify insert wear and index before a breakage, but also prevents sharp cutting edges from going unused and the insert being inadvertently discarded.

Machining steel is anything but easy, and most experienced machining specialists are open to any solution that helps them turn ISO-P steel. This is why CERATIZIT continues to refine its insert grades and apply its Dragonskin coating to prevent waste, extend tool life and further ensure a shop’s overall long-term success. Those shops that fail to evaluate new alternatives and best-practices when selecting an indexable insert grade will be squandering the potential for considerable savings.