Clear cut choices

Faster cutting speed, improved feed rates, greater depths-of-cut, finer finishing, longer tool life…all machine shops are seeking something extra from their milling cutters to provide an advantage in an ultra-competitive manufacturing marketplace. Fortunately, tooling companies are working harder than ever to capture the imagination of production engineers everywhere, with a seemingly constant stream of new products claiming to offer attractive returns. A case in point is WNT (0800 073 2073), which says the small size of its 2011-07 milling inserts belies the performance they can deliver, with increased feed rates being generated by the greater number of inserts available in each cutter body. Image: Increased federates from WNT's 2011-07 milling inserts By creating a 7 mm edge length insert for its 2011 range of milling cutters, WNT (UK) has been able to increase the number of inserts in a typical milling cutter body. For example, a 32 mm diameter cutter will now have eight inserts, compared to five when using the 11 mm edge length inserts. This equates to a feed rate improvement of around 40 per cent, depending on the application. Furthermore, the design of the insert with its geometry and 'notch' that provide performance and stability, especially when plunge milling – combined with the cutter body design that allows improved swarf evacuation – enables depths of cut up to 6 mm. Another innovative indexable insert milling solution is offered by TaeguTec (01937 589828). The company's LionMill, launched last year, is now being expanded with a new series of face mill cutters for steel machining, with 45° entering angle and corresponding inserts to offer end users additional machining options. The inserts for the new LionMill are available in TaeguTec's TT7080 and TT7070 grades for machining low and high carbon steels, alloy steels and iron. The new ISO inserts have been coated with an innovative new layer that enhances wear and chipping resistance. Image: New inserts are available for TaeguTec's LionMill For those interested in improved productivity for rough milling operations, the new DAH high feed milling system from Horn Cutting Tools (01425 481800) should provide the answer. Horn DAH has been developed specially for roughing with high feed rates at low cutting depth. The geometry of the triple edged inserts ensure favourable distribution of cutting forces, as it has been designed to direct cutting forces axially. This reduces the spindle load in shear and offers significant productivity and tool life advantages, says Horn. High feed milling strategies generally allow suitable tooling to absorb very high loads, using tooth feeds of up to 1 mm per tooth, comparing favourably with the relatively low cutting depths of 0.5 to 0.8 mm for conventional tools. Horn says its DAH milling cutters provide significantly better values. The cutting geometry, which combines 'soft' cutting with fast plunging, enables cutting depths up to 1.2 mm. Depending on material, feed rates up to 3 mm per tooth can be sustained, with a maximum cutting depth of 1.2 mm. HIGH-STRENGTH DEMAND Material is, of course, a pre-determining factor when selecting cutting tools. In light of the growing use of high-strength, low-weight materials such as titanium, Sandvik Coromant (0121 504 5500) has recently introduced two new milling grades. S30T and S40T are available for use with a variety of CoroMill cutters in operations such as face, shoulder, long-edge and high feed milling, as well as plunging, profiling and slot milling tasks. Insert grade S30T has been developed with productive titanium milling in mind. It combines the properties of a micro-grain carbide substrate with a wear resistant PVD coating. This enables very sharp cutting edges that resist fatigue and micro-chipping, offering machine shops longer times in cut, at higher cutting speeds. The premise behind the development of grade S40T is to overcome challenging machining conditions when milling titanium. It combines ultra-tough cemented carbide with a thin CVD coating to provide a grade that withstands vibrations and other difficult cutting conditions for longer times in cut. For hard or difficult-to-machine materials, new super-hard PCBN inserts from Mapal (01788 574700) are available in six grades to suit both smooth and interrupted cut applications on materials that include case-hardened steels, cast iron and super alloys. They can be supplied with a large selection of standard geometries and chamfers, and versions with multiple cutting edges. Image: New super-hard PCBN inserts from Mapal And for those wondering about cutters for softer materials, well, solid carbide cutters are usually deployed, and here Merlin Tools (01509 610300) says it has recently added over 100 new solid carbide tools to its aluminium range. These include 3-flute, 55° helix variants, complete with corner radius in both standard and long length. Diameters from 3 mm through to 20 mm are available, with corner radius from 0.5 to 4 mm. Also added are two series of long reach, 2-flute slot drills both in square end and ball nose styles, from 6 mm diameter through to 20 mm, with overall lengths up to 200 mm. Moving to cutters required for machining centre operations other than milling, Floyd Automatic Tooling (01462 491919) is now offering the Mikron CrazyMill for deburring and chamfering. This innovative new tooling system is available in three ranges: the Frontchamfer, Backchamfer and the Universal Radius Chamfer. HIGH GRADE CARBIDE All cutters in the CrazyMill series are manufactured from high grade carbide that is coated to deliver long tool life and high productivity. This enables the CrazyMill range to machine materials from gold through to hardened steels above 56 HRc, at cutting speeds of up to 200 m/min. For drilling operations, Kennametal (01384 408060) is introducing the first 'Beyond' inserts for holemaking applications. Three new grades are available: KCPK10, KCU25 and KCU40. The portfolio covers SPPX/SPGX square inserts, available in HP, FP and MD geometries, together with DFS drill bodies of 24.0 to 55.0 mm diameter. Kennametal's DFS indexable drill platform offers the economy of a square insert, having four edges in the outside pocket combined with the centering and high feed ability of a DFT trigon insert. Achieving up to 20 per cent or higher material removal rate (according to Kennametal) at the same tool life as standard inserts, the KCPK10 grade offers good abrasion and crater-wear resistance for high speed machining of steels and cast irons. First published in Machinery, November 2010 Box item Roll-type taps A new range of universal swarfless 'roll-type taps' has been developed by Walter (01527 839450), incorporating a special coating and geometry to enable high performance threading of both blind and through holes in high tensile materials, as well as aluminium and copper alloys. Image: Roll-type taps for high performance threading in blind holes The Walter Prototyp Protodyn S ECO plus series of taps include the S ECO Plus, a tool that provides a universal solution on every material up to a tensile strength of 1,200 N/mm2. The tap has a newly developed TiN coating, developed by Walter for swarfless thread forming, that extends the life of the tool and prevents cold welding of the material or any built-up edge when machining materials such as high carbon steels or highly abrasive aluminium alloys. First published in Machinery, November 2010