4" Rock Drill Down the Hole Bits ND45/DHD340A/COP44,SD4,QL40,Mission40

4" Rock Drill Down the Hole Bits :

Bit face shape selection:

1. Drop Center Bit

For high penetration rates in soft to medium hard and fissured rock formations. Low to medium air pressures. Maximum hole deviation control.

2. Concave Face

The all-round application bit face specifically for medium hard and homogenerous rock formations. Good hole deviation control and good flushing capacity.

3. Convex Face

For high penetration rates in soft to medium-hard with low to medium air pressures. It is the most resistance to steel wash, and may reduce the load and wear on the gauge buttons, but poor hole deviation control.

4. Double Gauge Face

This kind of face shape is suitable for fast penetration rates in medium to hard rock formations. Designed for high air pressures and good resistance to steel wash step gauge bit.

5. Flat Face Bit

This kind of face shape is suitable for hard to very hard and abrasive rock formations in applications with high air pressures. Good penetration rates an resistance to steel wash.

Carbide button shape selection:

1. Domed/Round Button

2. Parabolic/Semi-Ballistic Buttons

3. Ballistic Button

4. Sharp Button

5. Flat Button

4" COP44 DTH Button Bits: