In industries such as mining excavation, oil drilling, and road maintenance, cemented carbide buttons (also known as tungsten carbide ball buttons, alloy buttons, or drill bit buttons) are indispensable wearing parts. Thanks to the extremely high hardness and excellent wear resistance of tungsten carbide, these alloy buttons are inlaid on various drill bits or cutting tools to directly contact and crush rocks, coal seams, or road surfaces. According to different working condition requirements, cemented carbide buttons have obvious differences in geometric shape, size specifications, and material grades. This article will detail several common types of cemented carbide buttons on the market and their main uses, helping you select the most suitable model based on the actual construction environment when purchasing.
I. Classification by Geometric Shape
The shape design of cemented carbide buttons directly determines their efficiency and service life in rock breaking. Different shapes represent a balance between "penetrating power" and "durability".
| Button Type | Core Features | Core Advantages | Application Scenarios |
|---|---|---|---|
| Spherical/Ball Buttons | Hemispherical top, uniform force bearing | Extremely high impact resistance, not easy to crack | Extremely hard rocks, hard formations, and occasions requiring high tool stability |
| Conical Buttons | Sharp top, conical shape | Strong penetrating power, can cut into rocks quickly and improve drilling speed | Medium-hard and softer rocks. However, the tip is easy to wear or fall off when encountering extremely hard rocks |
| Wedge/Chisel Buttons | Top similar to a chisel, two inclined planes converging into a line | High efficiency in cutting soft materials or cracked rocks | Coal cutter picks, rotary drilling bits, and soft rock excavation |
| Parabolic/Spoon Buttons | Shape between spherical and conical, with a smoother top curve but slightly sharper than spherical | Balances the durability of spherical buttons and the penetrating power of conical buttons | Ordinary mining drill bits, suitable for various mixed rock formations |
1. Spherical/Ball Buttons
This is the most classic and widely used shape.
It has a hemispherical top and bears force evenly, with excellent impact resistance.
Compared with other shapes, spherical buttons are the least likely to crack.
It is suitable for extremely hard rocks, hard formations, and occasions requiring high tool stability.
2. Conical Buttons
The top is relatively sharp and conical.
It has strong penetrating power, can cut into rocks quickly, and improve drilling speed.
It is suitable for medium-hard and softer rocks. However, the tip is easy to wear or fall off when encountering extremely hard rocks.
3. Wedge/Chisel Buttons
The top is similar to a chisel, with two inclined planes converging into a line.
This shape is highly efficient in cutting soft materials or cracked rocks.
It is suitable for coal cutter picks, rotary drilling bits, and soft rock excavation.
4. Parabolic/Spoon Buttons
The shape is between spherical and conical, with a smoother top curve but slightly sharper than spherical.
It balances the durability of spherical buttons and the penetrating power of conical buttons.
It is suitable for ordinary mining drill bits and various mixed rock formations.
II. Classification by Application Field
The type of cemented carbide button depends not only on the shape but also on the tool it is installed on.
| Application Type | Core Requirements | Size/Structural Features |
|---|---|---|
| DTH Bit Buttons (Mining DTH Drill Bits) | Extremely high impact toughness | Usually large in size, with a diameter ranging from 8mm to 20mm |
| Tricone Bit Buttons (Oil Tricone Drill Bits) | In addition to hardness, extremely high requirements for material consistency | Suitable for downhole high-temperature and high-pressure environments, with high precision requirements |
| Road Milling Teeth | Need to cope with continuous frictional heating | Usually adopt cylindrical head or pointed head structure |
1. DTH Bit Buttons (Mining DTH Drill Bits)
Mainly used for mining and infrastructure blasting. These buttons are usually large in size, with a diameter ranging from 8mm to 20mm, and require extremely high impact toughness.
2. Tricone Bit Buttons (Oil Tricone Drill Bits)
Used for underground drilling thousands of meters deep. In addition to hardness, these alloy buttons have extremely high requirements for material consistency, because the cost of replacing drill bits downhole is very high.
3. Road Milling Teeth
Installed on road milling machines to remove old asphalt or concrete pavement. These teeth usually adopt a cylindrical head or pointed head structure and need to cope with continuous frictional heating.
III. Performance Comparison Table of Cemented Carbide Buttons
For you to understand the differences between different shaped buttons more intuitively, please refer to the following table:
| Button Type | Penetration Speed (RPA) | Impact Resistance | Wear Life | Typical Applicable Rock Formations |
|---|---|---|---|---|
| Spherical Buttons | Medium | Extremely High | Long | Granite, Basalt, Extremely Hard Layers |
| Conical Buttons | Extremely Fast | Medium | Medium | Sandstone, Limestone, Medium-Hard Layers |
| Wedge Buttons | Fast | Low | Short | Coal Seams, Mudstone, Soft Soil Layers |
| Parabolic Buttons | Fast | High | Long | Mixed Rock Formations, General Strata |
IV. Key Factors When Selecting Cemented Carbide Buttons
In actual work, it is not enough to only know the shape. You also need to pay attention to the following technical indicators:
- Cobalt Content: As a binder, the higher the cobalt content, the better the toughness (not easy to crack), but the hardness will decrease. The cobalt content of mining buttons is usually between 6% and 15%.
- Grain Size: Fine-grained alloys are usually harder, while coarse-grained alloys are more stable when subjected to large impact loads.
- Fit Precision: The diameter of the button's tail is usually slightly larger than the hole diameter of the drill bit (interference fit), and it is inlaid by cold shrinkage or hot pressing. If the precision does not meet the requirements, the alloy button is easy to fall off during work.
V. How to Extend the Service Life of Cemented Carbide Buttons?
- Timely Grinding: When the tip of the conical button is worn flat or the spherical button has obvious "snake skin patterns", it should be repaired or replaced in time to avoid excessive wear leading to the scrapping of the drill bit body.
- Control Pressure: Adjust the drilling pressure according to the rock hardness during construction. Excessive pressure will cause thermal fatigue cracks in the alloy buttons.
- Cooling and Temperature Reduction: In dry drilling or milling operations, maintaining good chip removal and cooling helps prevent performance degradation of the alloy due to high temperatures.
Summary
There are many types of cemented carbide buttons. From spherical, conical to wedge-shaped, each design is to cope with specific geological conditions. When selecting, the most expensive one is not necessarily the best. Only by comprehensively evaluating the rock hardness, drilling rig power, and construction cost can we select the product with the highest cost performance.
