(1) DTH Bit
Down-the-hole (DTH) bits are used with Down-the-hole hammers for drilling holes through a wide range of rocks types. In conjunction with DTH hammers, drill hammer bits are designed with a splined drive for rotating the bit in the ground. Drill bits are available in different sizes and different styles so they can drill a wide range of hole sizes.
Our variety of Down the Hole drill bits is manufactured using high quality materials to provide you with a fine balance between penetration capability and bit life. We offer a comprehensive range of standard and made to order drill bits on an extensive selection of shanks with a wide variety of head designs to suit every project.
Our DTH bits are interchangeable with these famous bits with CIR Bulroc, Mission, Mach, DHD, SD, QL, etc. series shank.
CIR Series Low Air Pressure DTH Bit |
Type | Dia.(mm) | Spline No. | Weight (Kg) |
CIR65 CIR70 CIR80 CIR90 CIR90 CIR90 CIR110 CIR110 | 68 76 83 90 100 130 110 123 | 6 6 6 6 6 6 6 6 | 2.50 3.40 3.45 3.50 4.50 9.50 6.40 8.50 |


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. 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.
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. 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.