The 7 Most Common Deep Hole Boring Problems and Solutions

Dorian Tool has some very detailed technical information in their Solution Tool catalog to address deep hole boring. First we're going to list the fundamental rules of selecting the correct boring bar and then take a deeper dive into the fundamentals of troubleshooting. 

If you want more information, technical specifications and much more detailed information on troubleshooting you can download the Solution Tool catalog below.

DEEP HOLE BORING
SELECTION CRITERIA

• The diameter size of the boring bar is limited from the size of the hole diameter to be bored.
  
• The boring bar should have the largest diameter possible for maximum cutting rigidity, but small enough to clear the hole for chip evacuation.
• The Boring Bar has to be held with the maximum rigidity and the shortest overhang possible to maximize cutting stability and minimize vibration.
• The selection and use of the right insert grade, geometry, nose radius and rake angle will be critical for a good surface finish and close working tolerance.
• The cutting parameter is to be correct for the material machined in accordance of the insert manufacturing cutting data.
• The hole, while machined has to be kept clear from chips to avoid tool breakage, boring bar vibration and the walls of the work piece undamaged.

---

7 MOST COMMON
DEEP HOLE BORING PROBLEMS

Poor Surface Finish, Poor Machining Tolerance & Poor Insert Life are the issues that every shop faces with cutting tools.  Deep hole boring is no different.  Below are some rule of thumb for a quick solution. As we said above, be sure to download the Solution Tool Catalog for much more technical information and solutions.

1. Boring Bar Cutting Ratio: If the incorrect boring bar cutting ratio is used, the boring bar will vibrate.
   
2. Boring Bar Diameter: Too small boring bar diameter will deflect under pressure and vibrate, too large boring bar diameter, will obstruct the evacuation of the chips.
   
3. Boring Bar Holding System: When boring bar is not held properly and rigidly in the boring bar holder, vibration will develop when cutting. A split Boring Bar Holder must to be used.
4. Boring Overhang:  When the boring bar is over extended it will vibrate (Steel bar 4 x Dia., Carbide bar 6 x Dia.,Solution Tool!™ (The NO! Vibration Re-Tunable Boring Bar) 8 - 14 x Dia.
5. Incorrect Insert:  Incorrect insert geometry, nose radius, rake angle, chip breaker, and clearance angle will cause vibrations.
6. Cutting Parameter:  When wrong cutting parameters are used for the specific material to be bored, and for the operation to be executed, the boring bar will not perform properly.
7. Chip Clogging:  When chips are clogged into the work piece bore, jamming the insert, wrapping around the boring bar, and thrown against the wall, the insert will be damaged.