Durable Threaded Rock Drill Bits with Tungsten Carbide Buttons for Underground Tunneling

1. Introduction to Taper Drill Bits

Taper drill bits, especially 7-degree Cross Drill Bits and Taper Button Bits, are widely used in mining, quarrying, tunneling, and construction projects. They are designed to withstand high-impact drilling in hard rock formations, offering excellent penetration efficiency, durability, and stability.

The most popular sizes in the industry include 32mm, 34mm, 36mm, 38mm, 40mm, 46mm, and 50mm, making them suitable for different drilling depths, hole diameters, and rock hardness levels.

Among these, the 7-degree taper angle provides a balanced performance between strong bit-holding capacity and easy removal during bit replacement.

2. Technical Parameters of Taper Drill Bits

When selecting the right cross drill bit or Button Drill Bit, customers often compare the following specifications:

2.1 Bit Sizes Available

• 32mm Taper Button Bit / Cross Bit – lightweight, suitable for small hole drilling, often used in tunneling and stone splitting.

• 34mm Drill Bit – slightly larger, providing better stability in fractured rock.

• 36mm Drill Bit – common in construction and road Cutting applications.

• 38mm Drill Bit – highly popular in quarry drilling and secondary rock breaking.

• 40mm Drill Bit – standard size for medium-to-hard rock drilling.

• 46mm Drill Bit – suitable for deeper holes, commonly used in mining operations.

• 50mm Drill Bit – large-diameter drilling, ideal for heavy-duty rock excavation.

2.2 Taper Angles

• 7 Degree – the most widely used taper angle, suitable for medium-to-hard rock, balancing efficiency and tool life.

• Other taper angles (11° and 12°) exist, but 7° is considered the standard for underground and quarry work.

2.3 Head Designs

• Cross Drill Bit – features a cross-shaped head, suitable for very hard or abrasive rock conditions, offering straight hole drilling.

• Taper Button Bit – equipped with tungsten carbide buttons, offering higher penetration speed and better wear resistance.

2.4 Button Types

• Ballistic Buttons – for faster penetration in medium-hard rock.

• Spherical Buttons – for longer service life in very hard rock conditions.

2.5 Materials

• High-quality alloy steel body

• Tungsten carbide inserts for maximum wear resistance

2.6 Performance Features

• High drilling efficiency

• Long service life

• Suitable for different rock formations

• Easy to handle and replace

3. Application Scenarios

The 32mm–50mm 7 Degree Cross Drill Bits and Taper Button Bits are used across multiple industries:

3.1 Mining Industry

• Drilling blast holes in underground mining

• Ore body exploration

• Ventilation shaft development

3.2 Quarrying Industry

• Granite, limestone, and marble extraction

• Secondary rock breaking

• Bench drilling in open-pit quarries

3.3 Tunneling & Construction

• Road and railway tunnel excavation

• Foundation drilling for buildings

• Rock slope stabilization

3.4 Hydro-power and Dam Projects

• Blasting preparation for hydro-engineering

• Large-scale infrastructure projects requiring rock excavation

4. Usage Instructions

To maximize efficiency and lifespan of taper button bits and cross bits, operators should follow these guidelines:

4.1 Proper Drill Selection

• Choose bit size based on hole diameter requirements.

• Select cross bits for very hard, fractured rock.

• Select button bits for faster drilling in medium-hard rock.

4.2 Correct Taper Angle Matching

• Always use 7-degree drill bits with rods and shanks designed for the same taper.

• Mismatch may cause premature wear or dangerous accidents.

4.3 Drilling Speed & Pressure

• Avoid excessive impact force; adjust air pressure to match bit size.

• Optimal drilling RPM ensures smooth operation and reduces wear.

4.4 Cooling and Lubrication

• Use water flushing to cool the drill bit and remove cuttings.

• Prevent overheating, which causes button breakage.

4.5 Regular Maintenance

• Re-grind buttons before they wear down completely.

• Inspect the bit body for cracks and replace if necessary.

• Store bits in a dry environment to prevent rust.

5. Common FAQs

Here are the most frequently asked questions regarding 7 Degree Cross Drill Bits and Taper Button Bits:

Q1: What’s the difference between a cross drill bit and a taper button bit?

• Cross Drill Bit: Best for very hard and abrasive rock, provides straight holes.

• Taper Button Bit: Best for faster penetration in medium-to-hard rock, offers longer lifespan.

Q2: Which size should I choose for my project?

• For small-scale tunneling or splitting: 32mm–36mm

• For quarry drilling: 38mm–40mm

• For mining and deep-hole blasting: 46mm–50mm

Q3: How often should I re-grind drill bits?

• Typically after 200–400 meters of drilling, depending on rock hardness.

• Timely re-grinding extends service life by 2–3 times.

Q4: Can 7-degree bits be used in all rock conditions?

• Yes, but they perform best in medium-to-hard rock formations. For very soft rock, larger taper angles may be more efficient.

Q5: How to reduce bit consumption?

• Use proper drilling speed and pressure

• Apply water flushing

• Regularly re-grind carbide buttons

6. Advantages of 7 Degree Cross and Button Bits

• Versatility – suitable for both surface and underground drilling

• Cost-effectiveness – longer lifespan reduces replacement cost

• High performance – fast penetration rates improve productivity

• Compatibility – works with various taper rods and drilling rigs

• Safety – precision design ensures stable and straight drilling

7. Why Choose Professional Manufacturers

Not all drill bits are created equal. A reliable manufacturer ensures:

• Consistent tungsten carbide quality

• Strict heat treatment process for steel bodies

• Advanced forging and CNC machining for precision

• Comprehensive after-sales support

Investing in high-quality 32mm–50mm 7 Degree Taper Drill Bits reduces downtime, improves efficiency, and ensures safety in demanding mining and quarry operations.

8. Conclusion

The 32mm, 34mm, 36mm, 38mm, 40mm, 46mm, and 50mm 7 Degree Cross Drill Bit and Taper Button Bit represent the backbone of modern drilling tools for mining, quarrying, tunneling, and construction.

Durable Threaded Rock Drill Bits with Tungsten Carbide Buttons for Underground Tunneling

For companies seeking reliable drilling performance, choosing the right size and bit type is crucial. Whether you need cross bits for hard rock or button bits for fast penetration, these tools offer a proven solution for demanding projects.