The Future of High Feed Milling in Modern Manufacturing

In today’s highly competitive global landscape, manufacturers face an extraordinary demand to produce high-quality parts and be highly productive and efficient, often with fewer resources. In the past, the traditional thought was to take as heavy a depth of cut as possible with a 90° or 45° milling tool and run “low and slow.” Although there is still a place for such techniques, those days have passed for most applications. Many of the machines on the market now are lighter duty and designed with smaller taper connections and therefore are not capable of the low and slow approach. They are, however, extremely capable of producing high-speed and highly productive tool paths. To get the maximum utilization out of these machines one must consider utilizing cutting tools designed with this task in mind.

When considering possible milling tools for machining a given part, a 90° tool is still commonly used. While there are plenty of applications where a 90° indexable tool can achieve the part requirements, it simply is not the most efficient way to remove material. Many shops are now turning to tools that capitalize on the strengths of the newer equipment such as high feed mills. This is due to the substantial increases in metal removal rates these tools provide.

At first glance, the available depth of cut would appear to be a limiting factor with high feed mills. However, when combined with the latest machine tools and programming technologies and utilizing the benefits of concepts like chip thinning, high-feed mills are generally much more productive than their large depth-of-cut horsepower-consuming predecessors.

The main premise of chip thinning is that as the lead (approach) angle of the tool becomes less, if the programmed feed-per-tooth remains unchanged, the chip thickness becomes less and the insert does not adequately develop a chip. Therefore, the feed-per-tooth needs to be dramatically increased to develop a chip with the proper thickness. For example, a common, general-purpose lead angle for a high feed mill is 17°. At 17°, the required feed-per-tooth to achieve the same chip thickness as a 90° tool is much greater. To further illustrate this, a 90° tool feeding at 0.004-inch per tooth produces a 0.004-inch thick chip (max chip thickness) if the cutter is 50% radially engaged into the workpiece. A high feed mill at 17° needs to feed at approximately 0.015-inch per tooth to produce the same theoretical 0.004-inch thick chip. In many cases 0.015-inch per tooth is a starting point, and with cutting geometries and edge preparations, the feed rate for a given material can be much higher.

ISCAR has a long-proven track record of developing new technologies to address the ever-evolving needs of the market. The ISCAR Mill4Feed family of high-feed milling tools is designed specifically with high productivity and predictability in mind. Featuring a high-positive 4-edge insert geometry and positive axial and radial rakes, users can expect a tool that provides a high degree of productivity while being easy on the machine. The Mill4Feed geometry, like most feed mills, transfers cutting forces axially into the spindle versus radially against the spindle-like experience with a 90° cutting tool, resulting in less abuse on the machine and a more stable cutting action. In addition, the tools feature coolant holes directed to each cutting edge for optimal cooling and chip control.

Mill4Feed inserts are available in several technologically advanced coatings and geometries. Inserts are available for ISO-P and ISO-K application groups, austenitic, duplex and “precipitation hardening,” PH stainless steel (ISO-M), high-temperature alloys (ISO-S), hard materials with hardness of up to 60 HRc (ISO-H) and non-ferrous materials (ISO-N). The free cutting, high-shear geometry and heat dissipation offered by the low lead angle makes the Mill4Feed an ideal solution for machining difficult-to-machine materials such as ISO-M and ISO-S materials.

The Mill4Feed tools allow machining of more complex geometries with the same tool due to the shallow depth of cut, often reducing or eliminating the need for semifinish passes. The low lead angle combined with light depth of cut allows for stable machining where a long gage length is required with much less vibration and deflection than traditional tooling. The application range includes facing, profiling, ramping, helical and circular interpolating, pocketing and side plunging making them a very versatile option for high-productivity machining in several applications and manufacturing segments.

Another benefit of the Mill4Feed tools is reduction of machine downtime. ISCAR achieves this by offering quick-change connections that utilize the popular Multi-Master and FlexFit adaptations, in addition to straight shank and face mill options. By simply screwing off one head and screwing on another, the machine can be back up and running in no time versus several minutes when having to replace an entire tool and touch off or measure prior to restarting the process. The Multi-Master and FlexFit adaptations offer a high degree of repeatability between each tool change, further reducing cycle and tool changeover times.

With the high demand to be efficient and competitive in a global market, ISCAR’s Mill4Feed high feed mills are a great option because they provide users with high metal removal rates and a higher degree of predictability. By dissipating the heat generated during the cutting process across a greater cross section of the insert, greater tool life can be achieved in comparison to the more common 90° and 45° tooling. In addition, high-feed mills require less power and are less abusive on the machine, adding to the stability and predictability of machining processes. This stability and predictability combined with higher metal removal rates enables users to confidently produce more parts in the same amount of time as traditional milling tools, in many cases without further investment in resources.

Click here to learn more about Mill4Feed and contact your local sales rep for a test today.

All images courtesy of ISCAR.