The Cutting Edge
A look at the latest tools for milling, drilling, and turning
By Jim Destefani
October's EMO show in Milan saw a raft of new cutting tools introduced by all the major manufacturers and their subsidiaries. Here's a look at some of the cutting tool technologies presented at the show--with a few other significant new releases thrown in for good measure.
In milling, the main emphasis is on tools for high-speed machining, tough workpiece materials, or both. Another trend is continuing development of milling tools for specific workpiece materials and cutting conditions.
New at EMO was the HSC-11 milling system from Ceratizit (Columbia, SC), which allows material removal rates to 3500 cm3/min at spindle speeds up to 56,000 rpm. Inserts for the system are ground in relationship to the insert seat, with precision said to be in the micron range. The product line covers a range of materials and application types.
New carbide milling grades from Kennametal (Latrobe, PA) are said to offer up to 30% increases in tool life for machining of ferrous work materials. KC935M is said to be excellent for medium to heavy machining of steels and nodular cast irons, and can be used dry or with coolant. KC915M is aimed at light to medium machining of grey and nodular cast irons. Both grades feature a new multilayer medium-temperature MTCVD coating that provides good coating adhesion with more even layer build-up than other coating techniques. Post-coating treatment produces smoother surfaces to improve chip flow.Walter Waukesha (Waukesha, WI) rolled out its Xtra-tec line of face and shoulder milling cutters. The F 4033 face milling tools use double-sided square inserts with eight effective cutting edges. With its neutral shape, the indexable inserts fit both right-hand and left-hand cutting tools. F 4042 universal shoulder milling cutters fitted with high-positive inserts are said to provide low power consumption and smooth cutting action. The tools are recommended for roughing and finishing steels and cast irons.
Several companies have recently taken the plunge to improve milling versatility. Sandvik Coromant (Fair Lawn, NJ) recently rolled out its CoroMill 210 milling cutter, which combines face milling and plunging capability. The tools are said to allow feed rates up to 4 mm/tooth and metal removal rates up to 1400 cm3/min in face milling, while plunging allows productive internal milling of deep cavities and external milling along deep shoulders. Cutters are available in diameters from 25 to 82 mm.
PLX plungers from Iscar Metals (Arlington, TX) are said to eliminate the need for angular retractions from deep cavities. The company says other plungers require a 45º angular retraction to avoid insert breakage and scratching of the workpiece during retraction. The PLX cutter enables fast retraction and eliminates special programming for the retract pass. Designed for rough plunging operations and light milling or semifinishing, the cutters use inserts with two cutting edges.
Also rolling out plunge mills is Stellram (LaVergne, TN). The company's 7791VS cutters are said to be ideal for roughing and semifinishing both ferrous and nonferrous materials at metal removal rates three to 10 times those of traditional profile milling. The system uses inserts with four cutting edges that can take either 8 or 11-mm maximum radial cut depending on cutter diameter.
New from M.A. Ford (Davenport, IA) are TuffCut XR solid-carbide end mills for both heavy roughing and finishing cuts in virtually all materials. The tools come in more than 240 variations, including square-end and multiple corner radii, along with the choice of stub, standard, long, and extra-long flute lengths. The company's "heli-pitch" flute geometry is said to allow increased feeds and speeds while reducing harmonics. Standard and metric tools from 1/8 to 1" and 3 - 25-mm diam are available with AlTiN coating.
Emuge Corp. (Northborough, MA) is also focusing on application-specific milling with introduction of solid-carbide end mills for machining aluminum alloys with low (5%) silicon content. The mills' geometry minimizes contact between chip and tool, improving chip evacuation and minimizing the chance of tool breakage. The tools use an aluminum-specific titanium diboride (TiB2) coating. Emuge also manufactures solid-carbide and insert mills for machining aluminum alloys with higher silicon content.
New tools for holemaking are aimed at improving flexibility and reducing tool inventories by allowing drilling of multiple hole diameters with a single drill body. An example is Iscar's ChamDrill, which uses a range of drilling heads, in 1-mm diameter ranges, on the same drill body to produce holes with depth to 8 X diameter.
Also using an interchangeable solid-carbide tip are new B 401x drills from Walter Waukesha. Tip inserts can be swapped out using only one clamping screw. Positive insert geometry and spiral chip flutes are said to ensure good chip flow and minimize cutting forces. Standard drills are available in diameters from 12 to 31 mm for hole depths to 7 X diameter; special lengths to 10 X diameter can be supplied.
Seco Carboloy's (Warren, MI) CrownLoc system, with interchangeable solid-carbide crowns, can now handle hole depths to 7 X diameter. The company also recently launched T-Geometry solid-carbide drills for holemaking in titanium and titanium alloys.
For small-diameter holes, ExclusiveLine drills from Guhring Inc. (Brookfield, WI) feature elliptical-shaped coolant ducts with cross sections that can be up to double those of conventional coolant ducts in tools of the same diameter. Guhring says the result is improved process reliability and longer tool life. The company also says a new edge grinding process allows precision production of tools down to diameters as small as 0.8 mm.
At EMO, the company released three new coatings for its holemaking tools: Super A, for difficult-to-machine work materials such as titanium alloys, Inconel alloys, and hardened steels; Ice, suitable for dry and minimum-quantity-lubrication machining as well as high-speed cutting; and amoC, an amorphous carbon material said to exhibit diamond-like properties.
For really deep holes, OSG Tap & Die (Glendale Heights, IL) has developed a new solid-carbide coolant-hole drill for producing holes with depths to 30 X diameter without a peck cycle. The result, according to OSG, is up to 15 X reduction in cycle time versus gundrilling. The micrograin carbide tools feature a reverse web taper and very smooth TiAIN surface treatment for good chip removal, and are available in diameters from 2.5 to 20 mm.
For turning tools, the big emphasis is on handling tough work materials at high speeds and feeds.
Kennametal's KB9640 is a new solid CBN grade with a CVD aluminum multilayer coating said to combine high fracture toughness and good resistance to chemical and crater wear. The tough, high-CBN substrate is suitable for roughing at large cutting depths, resulting in maximum process reliability and increased productivity. Main applications for the grade are high-performance roughing and finishing of pearlitic grey cast iron materials, as well as roughing of hardened steels, chilled cast irons, and hard coatings.
The company also rolled out new carbide grades for materials used in the aerospace, medical, and food-processing industries. KC5510 and KC5525 feature a nanostructured, high-performance TiAlN coating that is said to prolong tool life at high cutting speeds and enhance process reliability. Chipbreaker microgeometries result in extremely high edge stability and provide good workpiece surface finishes, according to Kennametal.
High-speed machining of cast iron is the application targeted by Kyocera Industrial Ceramics Corp. (Mountain Home, NC) with its CA4010 carbide grade. The tools feature a multilayer coating consisting of a TiN top coat for oxidation resistance; a thick, micrograin Al2O3 film to further increase oxidation resistance at high cutting speeds; and a columnar TiCN base coat to improve resistance to chipping and cracking. A new ZS chipbreaker geometry is said to improve insert stability, provide a stronger cutting edge suitable for interrupted cuts, and reduce vibration and machining loads.
For semi-roughing of superalloys and titanium alloys, Sandvik's patented Xcel tool is said to combine the programming ease of an 80º insert with reduced wear compared to a square insert used at a 45º entrance angle. The result is faster cutting and better wear resistance than rhombic inserts, the company says. The tools can machine into corners to produce complex shapes, offer good accessibility in confined spaces, and can machine in two directions. They are also said to offer reduced radial forces and constant chip thickness compared to round inserts.
Also new from Sandvik is CoroTurn XS, extra-small turning tools for internal turning, grooving, and threading of bores with diameters as small as 1 mm. Designed for use in Swiss-style CNC machines, the inserts fit into boring bars with internal coolant supply to improve chip evacuation and cooling. Boring bars range from 10 to 25.4-mm diameter.
Sometimes it's not the work material but dimensional variations in the parts themselves that can create problems for cutting tools. Seco-Carboloy's new TP3000 is designed for turning of parts with relatively large dimensional variations. The grade is said to handle heavy roughing, interrupted cuts, and high feed rates on workpieces with high piece-to-piece or batch-to-batch variability.
For high-production turning, Iscar's new HeliTurn system features tangential-clamped inserts with helical-shaped cutting edges said to enable use of very large (up to 8 mm) depths of cut and high feeds (to 1.2 mm/rev) when cutting steel. The inserts' four helical cutting edges ensure positive radial rake angles, resulting in lower cutting forces, improved tool life, and higher edge stability. Toolholders are available with square 25 and 32-mm shanks.
This article was first published in the February 2004 edition of Manufacturing Engineering magazine.