Slot broaching of small holes

Horn is expanding its slot broaching system with new type 117 inserts, which are suitable for internal diameters from 9mm

German tooling manufacturer Horn, represented in the UK by Ringwood-based Horn Cutting Tools, has expanded its slot broaching system with a large range of new type 117 inserts, which are suitable for internal diameters from 9mm. The company has developed a new carbide blank specifically for the insert family which is sustainable thanks to its low carbide content and an advantageous price per cutting edge. The tools are suitable for numerous applications including gear broaching, polygonal broaching and the broaching of keyways.

Horn product manager Andreas Härle said: “Development of the new carbide blank required new approaches in production and metrology. Due to the small size of the inserts, we had to make significant adjustments in handling, fixture grinding and measuring.”

The new system has an advantage over solid carbide broaching tools in that the tool shanks enable the broaching of longer and deeper grooves. Tool lengths are 20, 30 and 40mm. The shank diameters of the tool holders are 16 and 20mm. All types offer internal coolant supply directly to the cutting zone. Horn also offers special holders for mounting in broaching units from various manufacturers.

The portfolio of broaching tools has already demonstrated its capability during initial applications. One user previously achieved a tool life of 120 pieces when broaching a serration in a component made of hardened steel. By switching to the new Horn system, tool life increased to 1,040 parts, while maintaining the same cutting parameters. In addition to the significantly higher tool life, production costs fell due to the lower cost per cutting edge compared to that of the previously used carbide inserts.