If the crises of the past few years have made one thing clear, it is how fragile our supply chains are and how quickly they can be disrupted. The end result is that business is done by those who can deliver. Manufacturers and production companies are therefore bringing back in-house a number of processes that they outsourced abroad years ago for cost reasons. The trend was clearly evident at the AMB trade fair and was one of the reasons for its success. The only problem is if know-how also migrated together with the processes.

Trend with drawbacks: Bringing back manufacturing processes

In general, the successful machining of steel and, in particular, the precise and efficient milling of steel are impacted by a multitude of factors and their complexity can quickly become overwhelming. Tool manufacturers who can think in terms of the application are therefore welcome – and they are also willing to provide advice on complex production processes.

The Swabian medium-sized company of Karl-Heinz Arnold GmbH with its brand name of Arno Werkzeuge is known for its first-class turning and parting-off tools and has been a constant player in these processes for many years. What is less well known is that the family-run company also develops innovative milling tools and manufactures them in Germany. "With a high level of vertical integration, our own development expertise and global sales structures, we manufacture state-of-the-art, high-performance milling tools that are deployed worldwide for efficient milling," says Arno marketing team leader Christian Kimmich.

Ready to support with application know-how

This mainly includes a tool holder for corner milling and HFC indexable inserts, a multifunctional system for HFC and corner milling, a face milling system and solid carbide metal cutters. In particular, a new system for face milling incorporates a recent development. "One trend among users is towards smaller machining allowances for workpieces that run faster at higher feed rates," says Marco Staiger, application engineer at ARNO Werkzeuge.

This is precisely why ARNO has developed the new, stable FT face milling system 09, proving once again that the Swabians think with a focus on the application. The FT system is basically very stable and features a smooth cut and very quiet running. This provides the spindle with maximum protection and is the result of  a large flat face on the holders, a positive rake angle despite the negative mounting position and the differential pitch of the flutes.

More teeth and smaller double-sided indexable inserts

The new FT 09 milling system consists of two variants of stable tool holders covering a diameter range of 20 to 125 millimetres and equipped with eight flutes and matching smaller indexable inserts. The differential pitch of the tool holders ensures a quiet and low-vibration milling process. Especially with small allowances, ARNO promises a higher chip removal rate due to the higher feed rates. "Since we managed to achieve a narrower pitch in the tool holder despite the small diameter, we can now place more teeth on the tool," Staiger explains. This means that up to nine indexable inserts can be fitted, where only six were possible before. Despite the narrower dimensions, users do not have to dispense with cooling. Staiger again: "Through the internal channels for cooling media, cooling lubricant or – in the case of dry machining – air is fed directly to the cutting zone and ensures significantly longer tool life and optimum chip removal." A particularly convincing feature is the optimal utilisation of the flute with smaller infeeds up to a maximum of four millimetres. This means users no longer need to discard half-used indexable inserts.

Large pool of applications demonstrates engineering competence

Those who do not want to opt for "fast" or "fine" machining are best advised to use ARNO’s FD milling system. The nickel-plated and thus long-life basic holders for corner milling and HFC indexable inserts with four efficient cutting edges per insert achieve a high feed rate. These tool holders also have a differential pitch that reduces vibration and results in smooth surfaces. The system ensures a long service life and is easy to handle.

Most users set their machining priorities with indexable inserts in sizes 10 and 15. The smaller insert achieves high surface qualities due to its large wiper geometry. By contrast, the 15 mm inserts are ideal for roughing since they are extremely stable. ARNO offers different geometries and grades to flexibly adapt machining to the application in question. This is precisely where ARNO excels because they draw on the experience gained from a huge pool of applications and can advise on the most suitable tooling system for each case. The precision-manufactured positive chip breakers on the indexable inserts ensure a soft cut. And since they are also peripherally ground and polished, the PMA geometry can cut both aluminium and non-ferrous metals.

Application-based consulting raises productivity

With solid carbide metal cutters, the Swabian company also has tools in its portfolio that achieve optimum production processes with few downtimes thanks to fewer tool changes. The solid carbide metal cutters are made of ultra micro grain – an extremely fine grain carbide between 0.1 and 0.5 µm – and their consistent material properties are impressive. Depending on the design, they are coated with TiAIN, TiCN or AlCrN.

ARNO’s FE milling system is an alternative to solid carbide metal cutters. You can opt for efficient shoulders or high speed during HFC milling. "In both cases, users benefit from high feed rates, extremely smooth running and excellent cutting ability," promises Staiger. This is due to the highly positive mounting position of the indexable inserts and the spiral shape of the flutes, ensuring smooth material cutting.

It is also an ideal situation if the tool supplier can adapt to the needs of its customers with special product lines. With the Basic Series, Arno Werkzeuge offers efficient, rock-solid tools with many grades and geometries that are suitable for a wide range of machining tasks. On the other hand, the tools in the Major series are used when surfaces need to be outstanding, every minute counts when it comes to tool life, difficult-to-machine materials are machined or large production runs are required. They can be individually adapted, for example for coatings or tool holders.

Conclusion: Milling tools benefit from turning experience

With its carefully designed and well-engineered milling tools, Arno Werkzeuge has no reason to hide its light under a bushel. This is because it also benefits from the excellent turning and parting-off tools as well as from ARNO’s application experience. We were impressed by how the milling systems are precisely developed for different applications and yet offer the greatest possible flexibility. With its extensive portfolio, ARNO serves the trends in milling. Our conclusion: great!