Product Description
This six-tooth ball-button family references 38, 40, and 42 mm tunnel-drilling gauges and an oblique-hole face for use with a tapered drill-rod system. It is suited to development rounds and controlled rock excavation where angled flushing can help clear the contact zone. Review the task in the construction drilling application archive and compare the rock with the hard formation archive. The oblique-hole description does not make the bit suitable for directional steering or unconsolidated-ground control.
The source identifies six teeth, cold-pressed construction, a tapered rod, and the three gauge references. An alloy-steel body supports fixed carbide contacts, while the oblique-hole wording indicates angled flushing features rather than a guaranteed port number or orientation. The filename does not provide taper dimensions, actual face pattern by size, or whether all three gauges share the same six-tooth layout. Each variant must be checked for socket fit, insert arrangement, and port clearance before it is assigned to a drill.
Use 1,000–3,000 lbf/in of diameter and 25–60 RPM. Start with moderate settings because angled ports can only clean effectively when the rod passage and supplied air are compatible. Hard and abrasive rock may increase face and gauge wear; fractured contacts can cause one side of the six-tooth face to carry excess load. Inspect each angled passage whenever cuttings become finer or return volume falls. Flow is unspecified because no port area or compressor duty is given. The limitation is unverified taper and port geometry. Tunnel geology can be researched through the U.S. Geological Survey.
