Big things can come in small packages

Featuring a new coating, substrate and microgeometry, the carbide inserts are designed to machine bores in demanding, highly alloyed materials from 0.2-6.8mm diameter. Standard lengths are from five times diameter at the smaller end of the range to a maximum of 35mm.

The Supermini system offers more than 1,500 insert types for a host of different applications. Right and left-hand versions can be used in one standard Horn Supermini toolholder, available with or without internal cooling.

During development of the tool, a performance increase of 30% was achieved solely by modifying the substrate and keeping the coating and insert microgeometry the same. Horn then found that a sharper cutting edge resulted in higher metal removal rate and less cutting pressure. Although mechanical stress on the edge was elevated, the tougher substrate was able to cope.

A new coating system was devised, tailored to the combination of the tough substrate and the more durable cutting edge. It allows a denser layer of TiAlN (titanium-aluminium-nitride) with a more homogeneous structure to be deposited with excellent adhesion and improved smoothness. The enhanced anti-friction properties mean that less heat is transferred to the tool, so the cutting edge is exposed to lower thermal stress.

High-performance 105 Supermini tool life comparisons with existing substrates and coatings were carried out by Horn and results showed that using the new EG35 grade on cobalt-chrome, a popular alloy used in the medical sector, tool life was increased by as much as 60%.

In the case of carbon steel, tool life more than doubled and when tests were carried out machining tool steel, the tool life increase compared to competitors’ inserts was even greater.