The next level in modular milling tools

Since that time, the company has been busy developing, testing, and building inventory of DUO-LOCK, which promised even then to be ‘the most rigid and most precise interface in the marketplace.’

According to Thilo Mueller, manager of solid carbide end milling at Kennametal, today it is even better. He said the DUO-LOCK is the only modular end mill solution able to compete at solid carbide levels, and outperforms its nearest modular competitor by more than two to one. That means full-width slotting at depths up to 1x cutter diameter, and side milling up to 50% radial engagement at 1.5x the diameter deep, even in stainless steel, titanium, and other high-temp aerospace alloys.

Mueller says he´s excited about the tool´s robust machining qualities, but is equally enthusiastic about its broad initial product offering. “We have over 400 line items coming in the first wave, with many more coming early next year,”

He added: “These include the most popular size end mills in both inch and metric, as well as a broad array of adapters, integral shank holders, and extensions.”

Many of those extensions are equipped with HAIMER´s Safe-Lock technology, a secure clamping mechanism that eliminates concerns over tool pull out and creep in high-performance milling applications. HSK, CAT, BT, and comparable spindle tapers are also available.

One of the things that makes DUO-LOCK different is its intelligent thread design. Using FEA-based design tools, Kennametal has optimised the connection to eliminate any possibility of tool failure even at elevated loads. The result, says Mueller, is that DUO-LOCK handles 25% more torque than its closest competitor, permitting higher federates and axial depths of cut, especially in long reach conditions.

The cutting geometry is likewise different, and uses an upgraded HARVI front end with an asymmetrical flute design. This breaks up cutting harmonics, reduces chatter, and provides 20% or greater chip load per tooth compared to the solid carbide versions. The HARVI II 5 flute cutters also received an upgrade: a variable helix known for its full slotting capabilities in titanium.

The eccentric relief behind the cutting edge with HARVI III is also a proven performer in titanium and other heat resistant alloys, and is sure to satisfy the needs of customers looking for larger modular versions as well.

Multiple carbide grades are also available, including Kennametal´s proprietary Beyond grades KCSM15 and KCPM15, making DUO-LOCK a go-to solution for everything from heavy roughing to semi-finishing.

Mueller continued: “Because of the very small amount of tool run out, some of our customers are even seeing success in fine finishing applications.”

Since DUO-LOCK operates at far higher cutting parameters, the torque values are likewise much greater, an indicator to customers familiar with such tooling that DUO-LOCK is a different species within the modular machining world. DUO-LOCK´s double-cone locating surface provides Z-axis coupling repeatability of 10µm (.0004”) or better, and tool to tool repeatability in the 50µm (.002”) range, eliminating the need for offline pre-setting or tool touch-off in the machine. And the additional contact surface at the base of the tool assures radial runout at the coupling below 5µm (.0002”), improving run out at the cutting edge tremendously, similar to the 2^nd contact area enjoyed by KM or KM4X customers. And when the cutter´s dull, simply load it into a Kennametal Blue Box and ship it to one of the company´s reconditioning facilities around the world.

The result is a rigid, highly accurate tooling solution that offers greatly reduced setup time and simplified tool changeover, cutting performance equal to solid carbide, and the stiffness to remove more metal in less time than competing modular systems.

Mueller concluded: “We are understandably proud of the DUO-LOCK design, it´s an ideal solution for a wide variety of applications.”