System BTA Overview Solid drilling tools with brazed carbide inserts & guide pads with indexable inserts and guide pads Counterboring tools with indexable inserts and guide pads Trepanning with indexable inserts and guide pads Accessories drill tubes connecting chucks vibration damper pressure heads drill bushings spare parts adaptors tool presetter	Type 56 - Counterboring head, multi-cutter diameter range: 34.00 - 273.99 mm Type 38 - pull boring head. 1-start internal connection thread diameter range: 20.00 - 222.99 mm Type 58 - pull boring head. 1-start internal connection thread diameter range: 20.00 - 222.99 mm < back