How to Choose a Cemented Carbide Drill?

The cemented carbide drill bit breaks the rock through the weight on the drill bit and the impact load generated by its own rotation. In rock drilling, the drill bit is subjected to high-frequency impact loads, and subjected to a variety of complex stresses, such as torsion, bending, tension, and compression. It is subject to the abrasion and corrosion of rocks, rock dust, water and other media in the environment of high-speed rotation and collision.

Due to the relatively high price of cemented carbide drill bits, every mechanical processing practitioner is responsible for the correct use of the drill bit and the full use of the drill bit. How to use carbide drills correctly? There are mainly the following aspects:

Ⅰ. Choose the right machine for carbide drills

Carbide drill bits can be used for high-power, high-rigidity CNC machine tools and other machine tools, and the TIR of the tool tip runout should be guaranteed to be less than 0.02. However, radial drilling, milling machines and other machine tools have low power and poor spindle accuracy, which can easily cause the carbide bit set to be damaged untimely. It's better to take precautions to avoid this hidden trouble as much as possible.

Ⅱ. Choose the right handle of carbide drill

You can use spring chucks, side pressure chucks, hydraulic chucks, thermal expansion chucks, etc. However, due to the insufficient clamping force of the quick-change drill clamp, it is easy to cause the cemented carbide drill bit to slip and be damaged, so it should be avoided.

Ⅲ. The correct cooling methods of cemented carbide drill bits

1. For external cooling, attention should be paid to the combination of cooling directions to form an upper and lower trapezoidal structure and minimize the angle between the tool and the tool.

2. Pay attention to the pressure and flow rate of the internal cooling hard alloy drill bit, and prevent the leakage of coolant from affecting the cooling effect.

Ⅳ. The correct drilling process of cemented carbide drills

The qualified carbide drill manufacturers must be familiar with the drilling process, which is listed below.

1. When the inclination of the drilling surface is more than 8-10°, do not drill. The inclination of the drilling surface is less than 8-10°, and the feed should be reduced to 1/2-1/3 of the normal value.

2. When the inclination of the drilling surface is greater than 5°, the feed rate should be reduced to 1/2-1/3 of the normal value;

3. When drilling cross holes (orthogonal holes or oblique holes), the feed rate should be reduced to 1/2-1/3 of the normal value;

4. The blade hard alloy drill bit shall not be reamed.