German cutting tool and insert manufacturer Paul Horn unveiled new products and range expansions at the EMO 2023 trade fair in Hanover last month. Among the highlights was a boring bar with adjustable damping, which visitors could see 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, 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 adjustable from the outside by turning a screw to fine-tune the pre-tension of the rings. This capability allows users to set the boring bar accurately to minimise any vibration 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 can provide 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.

Markus Horn says: “As a precision tool manufacturer, we not only have to master our own products but the entire machining process, right down to the material being cut.”
For further information www.phorn.co.uk