Horn has expanded its product portfolio to include tools tipped with CBN for machining difficult materials such as superalloys and hardened steels. Ultra-hard CBN material is capable of smooth machining even during interrupted cutting when hard turning and grooving. By extending its existing standard ranges of Supermini 105, Mini 11P, 229 and 315 systems, Horn is able to deliver the CBN tools quickly from stock.

The Supermini system is available in left- and right-hand versions with different corner radii. Notably, the CBN-tipped variants are for internal machining from a diameter of 2 mm. Different lengths of solid-carbide body are available. Tools in the Mini family feature internal diameters from 6.8 mm and are available in left- and right-hand versions. The single-edged tool type 315 is for external grooving from a width of 0.5 mm. In the cutting insert system 229, the higher performance substrate CB 35 replaces the previous CBN substrate CB 50. Inserts are available with two different corner radii and cutting widths from 3 to 6 mm.

CBN is the second-hardest material after diamond. Tools made from CBN wear much more slowly than other cutting materials when used appropriately. It is consequently possible to achieve higher dimensional and profile accuracy, even when machining hard materials such as steel up to 70 HRc.

There are no different grades of CBN. Differentiation between tools is down to the CBN volume fraction, the fillers, grain size and the ceramic/metallic binder phase (cobalt/nickel), which results in different CBN substrates. Hard machining usually takes place without coolant, as these cutting materials have high heat resistance and the elevated temperature within the chip formation zone has a positive effect.
For further information www.phorn.co.uk