Horn to launch new tools for reaming and thread milling, plus new geometry and coatings at MACH 2022

​A new, modular system for reaming large diameter holes has been introduced by Horn and will be on show for the first time in the UK at MACH 2022 in Hall 20, stand 340.

Offering high precision, flexibility and easy handling, DR-Large reamers have exchangeable cutter heads with multiple solid carbide inserts, resulting in high cutting values, short cycle times and low costs. The interface of the insert seats has been designed to offer precise interchangeability to within a few microns and tool setting is unnecessary when exchanging the cutter head.

The versatile, interchangeable reaming system is suitable for bore diameters from 140 mm to 200.2 mm. Six cutter heads cover the range of diameters in 10 mm increments, with two sizes of head fitting on each size of reamer shank. Modular construction and an ABS-compatible interface means the tool can be extended to any length, in theory without limit. All reamers are equipped with direct internal coolant supply to each cutting edge.

Reaming is an economical machining process. Compared to boring holes to tight tolerances, it is faster and can significantly reduce cost of production. Until now, reaming tools on the market in these larger sizes have been either special brazed tools or diameter-specific reamers with fixed inserts.

With such tools, which tend to be delicate and heavy, replacing worn inserts is a complex process and calibration can be tricky for many users. Horn offers a practical alternative with its exchangeable-head, pre-calibrated DR-Large reaming tools and its customer service department offers quick and simple reconditioning.

New tools for milling small holes

In evidence also at the show for the first time will be Horn's extended range of products for circular interpolation milling of holes down to 8 mm diameter. The triple-edged 304 system offers a versatile, productive solution for internal groove, thread and profile milling as well as finish boring and chamfering. The insert has a cutting diameter of 7.7 mm. In conjunction with various vibration-damping carbide shanks, which feature an internal coolant supply, the tool is more economical and versatile than solid carbide milling cutters for machining smaller diameters.

The inserts are available in widths of 0.5 mm, 1 mm, 1.5 mm and 2 mm. For milling circlip grooves, Horn offers the system with cutting widths of 0.8 mm, 0.9 mm, 1.1 mm and 1.3 mm. In the case of the full radius versions, radii of 0.4 mm, 0.6 mm and 0.8 mm are offered. To enable the milling of chamfers, angles of 45, 30 and 15 degrees are available. Regarding the substrates, Horn uses coated grade EG55 for general steel machining and IG35 for machining stainless steels and superalloys.

The Horn circular milling system offers users many advantages, including a high level of reproducible quality. It is fast, reliable and achieves good surface finish. During processing, the tool plunges into the material either at an angle or horizontally and is interpolated either in a circle, or helically to produce a thread.

High-performance coatings for carbide inserts


At the exhibition, Horn will explain the importance of two new, high-performance coatings, IG6 and SG3, it has introduced for the manufacture of carbide inserts used in turning applications. Despite being less than 0.005 mm thick, such coatings can extend service life by a factor of 10 or more compared to uncoated inserts.

IG6 is a copper-coloured, aluminium-titanium-silicon nitride (AlTiSiN) coating for machining steels in groups P and M with Horn's S224 and S229 grooving systems. In conjunction with an adapted carbide substrate, the coating allows faster material removal rates and significantly extended service life. Standard inserts are available from stock, while for special designs, Horn Greenline orders can be delivered within five working days of the customer signing off on the drawing.

Horn's SG3 coating is designed for machining titanium alloys and superalloys, as well as for hard turning and hard grooving applications. It can withstand temperatures of up to 1,100 degrees Celsius and is designed to deliver outstanding performance when working with materials that are difficult to machine. Now that the advantages of the tool coating have been proven on selected Horn tool systems, the 105 Supermini grooving and boring system products are available from stock.

Over the last 15 years, Horn has developed a high level of expertise in the coating of precision tools, starting with five employees and one coating system and growing to over 50 employees working across fourteen coating systems and the accompanying peripheral equipment.

Its engineers are constantly researching new coatings and developing existing ones with the aim of delivering ever higher performance. Horn continually invests in new, modern technologies. In 2015, the company CemeCon delivered to Horn the first of three HiPIMS (high power impulse magnetron sputtering) systems, which was the first in the world.

The technology has many advantages and provides new opportunities when coating tool inserts. It enables the formation of coatings that are very dense and compact, as well as extremely hard and tough. They have a homogeneous structure and exhibit an even thickness, even on complex tool geometries. They also demonstrate good layer adhesion, ensuring cutting edge stability. Thanks to its high temperature resistance, the coating serves as a heat shield and reduces the amount of heat transferred to the carbide.

Optimised geometry for dynamic HPC milling

Making its UK debut will be Horn's expanded DS range of solid carbide end mills with a new geometry for HPC (high-performance cutting) milling of high strength steels at elevated material removal rates. It particularly excels in dynamic roughing applications as well as in standard roughing cycles. Different helix angles create an irregular tooth pitch, making operation exceptionally smooth. The end mills are available in diameters from 2 mm to 16 mm as standard, with four or five flutes.

The tools’ optimised face geometry reduces the cutting pressure during linear or circular ramping. Improved chip spaces ensure optimal process reliability during chip formation and removal. The system also demonstrates good performance during finishing. Smooth operation means that high surface quality can be achieved during side milling, for example. HPC milling of high strength steels at fast metal removal rates places significant demands on the tools. New carbide substrates and new tool coating technologies make this process feasible. Horn relies on the ES3P grade, again with a HiPIMS coating.