Horn to launch boring bar with adjustable damping

German cutting tool and insert manufacturer Paul Horn, will unveil new products and range expansions on its 580 square metre stand, A54, in Hall 5 at the EMO 2023. One innovation will be a boring bar with adjustable damping, which will be shown carrying a grooving insert.

A long overhang can cause a turning tool to oscillate when boring internal geometries. In addition to causing chatter marks on the surface of the machined component, the vibrations can lead to a significant reduction in tool life. For unfavourable length-to-diameter ratios, even damped boring bars may vibrate under certain conditions.

To address this problem, Horn has developed a boring bar that can be set to match the oscillation amplitude during machining. Precise adjustment enables vibration-free turning, resulting in better surface quality and a significant increase in insert life.

The damping element, a carbide rod supported in O-rings, is adjusted from the outside by turning a screw to fine-tune the pre-tension of the rings. This allows the boring bar to be set accurately to minimise the vibration that is predicted to occur during a machining cycle.

As standard, Horn offers the boring bars from stock in length-to-diameter ratios of 5:1 and 8:1. Higher ratios are available as special tools. In the case of grooving, Horn offers the S224 double-edged system. The manufacturer’s BK 224 cassette system ensures a stable interface between the boring bar and grooving insert. To increase process reliability further, the tools have an internal coolant supply.