Dampened Boring Bars

When boring deep holes, there is no better solution than a dampened boring bar. Vibrations or Chatter are a constant battle when boring, the length to diameter ratio of a boring bar determines it s effective range. Boring bars can be made from different materials which change the bars properties. In this video, I demonstrate setting up a dampened bar at a 9 to 1 ratio. That means for this 1. 000 diameter bar, 9. 000 is extended from the holder. The effective length to diameter ratio of a common steel boring bar is 3 to 1. Ratios of 4 to 1, or even 5 to 1 are possible, often with significant experimentation though. (This is demonstrated via the knock test at different projection ratios. If the bar is tapped and it reverberates, it will likely chatter, if a solid thud is heard, the bar will likely cut well. ) The effective length to diameter ratio of a carbide boring bar is 6 to 1. Greater ratios are possible once again through experimentation. The trend here is the more you spend the deeper y