The most important issue facing the mold and die industry in recent years is throughput. Throughput is the amount of work a shop can complete in a set amount of time. This idea of productivity has been under constant review with the pressure from overseas competition.
To survive in the global market with shrinking leadtimes, manufacturers are forced to embrace new time-saving technology.

Recently, that technology has been high-feed tooling. Grinding technology has transformed high-feed tooling from large insertable tools to a range of sizes and styles. This new tooling selection has proven to be an irreplaceable solution in many applications and effective for all industries involving machining.

In this article, high-feed tooling will be defined and proven with some common examples. By using a high-feed machining strategy, this technology can be used on any machine tool. Keeping throughput in mind, high-feed tooling and a high-feed machining strategy can be the key to maximizing shops’ machining efforts.

High-Feed Geometry
With new five- and six-axis CNC grinding technology, cutting tool manufacturers have been able to create almost any geometry. With this increase in grinding technology, high-feed tooling has been reborn. The definition of high-feed geometry is producing a positive cutting edge out of a series of continuous radii with no tangent point to induce wear. The geometry must allow the chip to flow up and out of the cut quickly and smoothly. This cutting motion allows the use of heavy chip loads to achieve very high feedrates.

The geometry also must induce a chip thinning factor. The chip thinning factor allows the cutting tool to generate all cutting forces upward toward the spindle. With these cutting forces in place, it helps eliminate vibration and tool deflection, which results in a more rigid cutting condition that is safer for your spindle. To achieve these requirements for high-feed tooling, it is important the tool be fully ground in a 3-D helical motion. Straight grinding will not produce true high-feed results.

High-Feed Tooling
In the past, high-feed tooling was only available as an insertable tool in larger diameters. As stated above, grinding technology has reinvented high-feed tooling. High-feed tooling is now available in a two-flute insert in sizes 3/8″ (10 mm) to 1″ (20 mm) or as four flute solid carbide in sizes 1/8″ (3mm) to ½” (12 mm).

With this overlap of technology, many smaller roughing applications can be streamlined. Machining times in some applications have been reduced by up to 70 percent. This reduction in machine time is due to the high-feed geometry. By allowing heavy chip loads on small diameter tools, high feedrates can be achieved in smaller machining applications. High-feed tooling is proving to be an irreplaceable solution in most roughing applications.

High-Feed Machining Strategy
High-feed geometry is the future of high-speed roughing. In the past, roughing operations have been evaluated only on their metal removal rate. This evaluation usually puts into process the machining strategy of using the biggest tool possible and working down sizes. However, by properly using high-feed tooling, users can achieve the same—if not better—metal removal rate with a much smaller tool.

A high-feed machining strategy should be based on eliminating re-roughing operations and getting to allowable corner radii or net shape faster. To illustrate the different strategies when roughing, a multiple cavity job example has been chosen. The same core geometry was roughed using a conventional roughing approach on one cavity and a high-feed roughing approach on the other.