CNC milling machines and machining centers need the support of stronger milling cutters

machines and machining centers require more versatile milling cutters – a need for more advanced milling tools from tool suppliers over the past few years.

In the past, special tools were often the only effective solution, especially for high-volume production. Today, however, there is a need for more flexible production methods, and the new milling cutter concept offers tools with a wider range of machining capabilities. Modern tool design and manufacturing enables more complex tool concepts, increased output and more reliable machining processes with CNC machines.

Development of tool technology

Milling cutters and inserts were previously regulated by ISO standards, so interchangeable tools were available from different suppliers. But to comply with the standard, there are also limits for milling cutters and inserts. The ISO standard specifies the insert shape, thickness, not only the circumference but also the size of the chuck and wedge clamp used to insert the insert, as well as the size of the tool body. Blade grades, grinding, and chip breaker designs are all limited to a certain range. Full compliance with ISO standards means that users and tool suppliers face severe process and performance constraints.

Compared to ISO standard milling cutters, the milling cutter concept now offers more freedom to tool suppliers, and optimized tool and insert design provides CNC machining centers with more powerful universal machining capabilities. The new tool concept enables better solutions for machining safety, machining accuracy, surface finish, adaptability to different machining paths, metal removal rates, tool overhangs and high-speed machining.

Now, in order to adapt to the current operating processes and materials, concept milling cutters have been optimized and accepted by the entire industry, for example: Sandvik Coromant about 80% of milling cutters are CoroMill milling cutters. Compared to ISO standard tools, these concept tools cut metal several times faster, cut with less force, and often guide the direction of force more appropriately. At the same time, the concept tool runs out much less than ISO standard tools, guaranteeing smaller part tolerances and less cutting edge wear. Minimal axial and radial runout means higher cutting edge accuracy, improved surface finish, smaller part tolerances and longer tool life. These tools also distribute the machining load more evenly and cut faster with less noise, vibration and wear.

These modern concept tools also offer technology for high spindle speeds, fast feed milling and hard part machining, and increase the chance of dry milling. CoroMill design features make the concept tool design simpler, require less adjustment and maintenance, and the cutter body is machined from pre-hardened steel with high rigidity and precision, and precision positioning inserts are available in different pitches for a variety of machining applications.

Consequences of using obsolete milling cutters

The use of obsolete milling cutters can seriously affect machining economy and production safety, so that milling workshops using non-modern concepts can be significantly inferior in machining competitiveness. Investing only in advanced machining centers or other rotary spindle milling machines without updating milling cutter and insert users can only get a one-sided improvement.

Some manufacturers still use outdated special milling cutters, boring cutters or other special tools, and the advancement of cutting tool technology and CNC machining capabilities has brought them new development potential. However, these vintage tools are often designed and used for specific cutting steps on a component or a class of parts. In other words, the machining center is equipped with individual rotary tools for each component and size.

Standard tools that have been specially designed with these dimensions are, in a sense, a return to the days of boring and milling with milling machines or special machines with limited axial machining capacity. Especially for inner surface machining, each diameter, each surface, chamfer and groove, even if the dimensions differ by only a few millimeters from each other, require a separate tool. The use of adjustable insert seats on the chuck sometimes offers limited flexibility.

With the widespread use of multi-spindle CNC machining centers, tool movement is no longer restricted. Therefore, a single tool can complete at least several machining tasks, if not complete all machining. Programming different toolpaths has become fairly straightforward, and slash and arc interpolation is also possible. The tool offers greater flexibility and a wider range of motion, which can be adapted to different dimensions on the part with simple program adjustments.

With fewer tools, the production time increases

A European manufacturer of off-road vehicles has paid off with modern concept milling cutters on its flexible line for horizontal machining centers. The line processes different forms of housings for wheel loader axles. This retrofit is only part of the overall benefit engineering and is aimed at improving the production performance of drivetrain components, in particular by improving the processing of side shells through increased production efficiency. Previously, this flexible line used special boring tools to machine cast iron side housings of different sizes. Each component has several different sizes of inner diameter and inner surface to be machined. After the analysis, it was realized that the concept tool could replace several previously used boring tools and was not limited to the hole size. For example, small-diameter long-edged tools can be interpolated, so they can machine a variety of size center holes, and machining different sizes requires only changing the program. The tools are versatile for different sizes and operations, and standard concept tools are also used for face milling.

Operators also believe that concept tools take machining process safety to a new level, which is also a big step forward. Tool adjustment and maintenance are easier and more reliable. CoroMill knives feature a center screw that gets the correct torque by supplying a TORX wrench with the knife, making the blade easy to clamp. This is not a big move, but it is of great significance to ensure the safety of the processing process.

The use of the CoroMill concept milling cutter and the integrated interface of Coromant Capto also offers many benefits, such as a 25% reduction in machining installation time, a 50% reduction in the number of tools and a higher level of process safety. The new machining method also simplifies the installation of parts on the machine. It is estimated that production times can be reduced by another 10% by improving processing.

New concept tools

Updated concept tools, such as the CoroMill 390 long-edged tool, with variable blade sizes to suit a wide range of applications; There are also CoroMill Century 590 face milling cutters specifically designed for machining aluminum alloys.

Modern long-edged milling cutters, equipped with several inserts in machining, are a very effective metal cutting tool under the existing machine power. Due to the geometry of the negative rake insert, the use of this tool was previously limited, mainly for heavy-duty cutting. The 390 long-edged tool development provides a smooth tool with machining characteristics that enables high table feeds with the lowest power consumption.

Aluminum processing

The new generation of concept tools for the CoroMill Century 590 face milling cutter for aluminium machining is used in a wide range of applications – from series production in the automotive industry to demanding processes in the aerospace industry. The 590 tool is available from carbide inserts to polycrystalline diamond inserts for rough to superfinishing.

Aluminum milling tools have long been looking forward to major developments. The introduction of Century Tools provides a new means to improve machining performance, process safety and quality consistency when machining a wide range of aluminum alloys. This tool is designed for high-speed machining and can be safely used for spindle speeds up to 40,000 r/min. Designed with a small number of parts, lightweight inserts with high-speed cutting edges (cutting edges) mounted on serrated insert seats for minimal runout. The tool is easy to use, and adjustable and precise positioning with a single adjustment screw in one axis reduces downtime and repair time.