How to Select Inserts for Deep Hole CNC Drilling

Deep hole CNC drilling is a critical process in many manufacturing applications, often used to create holes that extend into the center of a workpiece. The selection of inserts for this process is crucial, as it directly impacts the quality and efficiency of the drilling operation. Here are key factors to consider when selecting inserts for deep hole CNC drilling:

Material Type

Inserts come in various materials, each with its own advantages and disadvantages. High-speed steel (HSS) is common due to its versatility and cost-effectiveness. Carbide inserts are more expensive but offer higher wear resistance and better performance at higher speeds. Tungsten carbide is another option, offering the highest hardness and wear resistance, but at a higher cost.

Insert Shape

The shape of the insert should match the drilling application. Standard inserts have a flat bottom, which is suitable for most general-purpose drilling. For more complex holes, inserts with different Carbide Drilling Inserts shapes like trapezoidal or hexagonal may be necessary. Consider the toolholder and machine capabilities to ensure compatibility.

Edge Geometry

The edge geometry of the insert affects the chip formation and the drilling efficiency. Positive-rake inserts are typically used for their good chip flow and reduced friction. Negative-rake inserts can be used for better surface finish and for drilling in materials that are prone to clogging. Neutral-rake inserts provide a balance between chip flow and surface finish.

Insert Coating

Coatings on inserts can significantly improve performance by reducing friction, heat, and wear. Common coatings include TiN (Titanium Nitride), TiCN (Titanium Carbonitride), and AlTiN (Aluminum Titanitide). The choice of coating depends on the material being drilled and the desired performance characteristics.

Insert Size and Diameter

The size and diameter of the insert must be appropriate for the hole size and depth. For deep hole drilling, it's essential to maintain a sufficient stand-off distance to avoid excessive heat and tool deflection. The insert Carbide Inserts should be large enough to support the cutting forces but not so large that it creates unnecessary friction or instability.

Insert Mounting

The mounting system for the insert should be secure and compatible with the machine's toolholding system. Consider the insertion and removal process, as it can impact the efficiency and safety of the drilling operation.

Drilling Conditions

Understand the drilling conditions, including the material, depth-to-diameter ratio, and drilling speed. These factors will influence the selection of the appropriate insert and cutting parameters.

By carefully considering these factors, manufacturers can select the most suitable inserts for deep hole CNC drilling, leading to improved drilling performance, reduced tool wear, and higher quality finished parts.