Drilling

Choosing the right drill bit is a critical step in any drilling process, as using the correct drill bit not only enhances the machining process but also improves the quality of the manufactured part.

The most commonly used type of drill bit in the industry is the twist drill, recognizable for its spiral-shaped cutting flute. Twist drills are typically made of either high-speed steel or carbide, with the latter becoming increasingly common in modern production environments due to CNC machining. Solid carbide drills with through-cooling are favored for their efficiency and durability. For drilling larger diameter holes, indexable insert drills or point drills are often used, as they allow for the replacement of worn inserts with new ones, making them a cost-effective choice especially for larger diameters.

High-speed steel (HSS) twist drills remain popular, particularly in smaller production runs and in managing unstable conditions. HSS drills are also favored as hand tools or in manual machines, where their reliability and easy availability make them a viable option. Materials used in HSS drills, such as HSS-E and HSS-E-PM, offer improved durability and heat resistance, allowing them to be used with more challenging materials.

Carbide drills represent the new generation of twist drills, offering significantly better performance and precision using a carbide composite made of tungsten carbide and cobalt. They are equipped with through-cooling channels, enabling faster chip removal and better cooling as drilling depth increases. Carbide drills are often the best choice in CNC machining centers, where high productivity and precise hole dimensions are the goals.

Point drills and indexable insert drills are especially good options when making large holes or when aiming to minimize tool costs in mass production. In these types of drills, a worn tip or cutting edge can be quickly replaced, saving time and money in the long run. Additionally, these drills allow for versatile application across various materials and machining conditions.

The importance of using the appropriate cutting fluid in drilling cannot be understated. It must be compatible with both the material being machined and the tool being used. When drilling deep holes or using through-cooling tools, it is crucial to ensure a high-pressure system or maintain the cleanliness of the cutting fluid to ensure the drilling process proceeds smoothly and the end result meets specifications.