Drill Tube Selection and Maintenance for BTA Drilling
I select drill tubes based on diameter and length for the job. The drill tube connects the BTA cutting head to the machine spindle. It must be straight, rigid, and properly maintained to produce straight holes. A bad tube produces a bad bore no matter how good the cutting head is. Tube Diameter Selection The tube diameter is determined by the hole size and the coolant flow requirement. The tube OD needs to be about 8-12mm smaller than the bore diameter to allow coolant to flow through the annulus between the tube and the bore wall. If the tube is too small, the coolant flow is restricted and chip evacuation suffers. ...