Low cost per edge drives new face mill cutter designs


Extracted from a paper by Christer Jönsson, corporate product manager milling, Seco Tools

In today’s competitive manufacturing market, industry is looking for the perfect cutting tool that offers high productivity, versatility and accuracy at a low cost per edge. In response, cutting tool companies are developing new precision-based solutions that offer improved economy by having even more cutting edges per insert, as well as better efficiency by performing both roughing and finishing operations.

Many of latest generation of face milling tools feature pre-hardened cutter bodies that maximise tool life and performance, as well as make use of inserts with as many as 16 cutting edges to minimise cost per edge for a lower cost per part. Some companies have even placed high emphasis on creating the perfect fit between the insert and its corresponding pocket to maximise the effectiveness, performance and tool life of a cutter.

Before purchasing a face mill cutter that presents multiple cutting edges, however, it is important for manufacturers to closely review their cutting processes to determine the best insert grades and geometries, cutter pitches and lead angles for their applications. It is also a good idea for them to evaluate the real costs of their cutting tools.

As manufacturers strive to reduce costs without sacrificing quality, inserts that provide as many cutting edges as possible are growing in popularity, especially in the general engineering and automotive industries.

While more traditional face mills typically use inserts with four edges, cutting tool companies are now adding more and more cutting edges to their inserts to create the best possible economy for their customers. In fact, some face mill inserts provide as many as 16 cutting edges – for example, the Double Octomill™ from Seco.

Seco is able to achieve 16 cutting edges because each pocket on the Double Octomill face milling cutter features a negative axial angle that allows for the use of double-sided inserts. The inserts themselves use a positive rake angle to minimise power consumption while achieving higher cutting speeds for a significant increase in productivity.

Additionally, as the popularity of multi-edged inserts continues to grow, cutting tool companies are making them as thick as possible to ensure high strength and process security with low risk of edge breakage.

Nowadays, companies also offer a wide variety of high-performance insert grades and geometries so the cutter can operate effectively in various materials and processes. Some of the more advanced grade coatings manipulate aluminium and oxygen at the atomic level, allowing the inserts to have unmatched toughness and abrasion resistance for a longer, more predictable tool life.

With respect to insert geometry, those with small wipers are ideal for roughing operations, while wider wiper edges can perform roughing and finishing in a single operation, producing superior surface finishes. In the case of the Double Octomill, Seco’s M14 geometry with a 0.45 mm wiper flat is ideal for roughing, while the M15 with a 2.11 mm wiper flat is more suitable for finishing operations. Then there is Seco’s M13, which has the same wiper flat as the M15 but has a more positive geometry, making it perfect for lighter cutting.

When designing modern face mills that boost productivity and cut operating costs via multiple cutting edges, cutting tool companies are taking a close look at the relation between the physical shape of an insert and its corresponding pocket.

In fact, companies, including Seco, are going the extra mile and grinding location grooves on the inserts to ensure they precisely align between the edge and the seat of each cutter body pocket. This enables the

cutter to achieve very tight tolerances because there is always the same distance between the edge and the support surface.

With its Double Octomill, Seco is taking the perfect fit even further as the only cutting tool company to develop insert pockets that incorporate a strong centre lock screw and grooves for axial and radial high speed steel location pins.

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