How to Sharpen Metal Drill Bits
Metal drill bits are essential tools for various metalworking tasks, but over time, they can become dull and less effective. Sharpening metal drill bits is a crucial maintenance task that can extend the life of your tools and improve their performance. In this article, we will guide you through the process of how to sharpen metal drill bits, ensuring that your tools are always ready for action.
Understanding the Drill Bit Geometry
Before diving into the sharpening process, it’s important to understand the basic geometry of a metal drill bit. A typical drill bit consists of a shank, a body, and a cutting edge. The cutting edge is the part that does the actual drilling, and it is made up of several cutting lips or flutes. These flutes help to remove the metal chips from the hole being drilled.
Materials Needed
To sharpen metal drill bits, you will need the following materials:
– Metal drill bits that require sharpening
– A drill bit sharpener or a file
– A grinding wheel or a bench grinder
– A piece of fine sandpaper or a polishing cloth
– Safety glasses and gloves
Step-by-Step Guide to Sharpening Metal Drill Bits
1. Inspect the Drill Bit: Begin by inspecting the drill bit for any signs of damage or wear. If the bit is excessively worn or broken, it may be time to replace it rather than sharpen it.
2. Set Up the Bench Grinder: Secure the bench grinder to a stable surface and adjust the grinding wheel to the appropriate speed for sharpening metal drill bits. The speed should be between 2800 and 3500 RPM.
3. Grind the Cutting Edges: Hold the drill bit securely in the chuck of the grinder. Position the cutting edge at a 60-degree angle to the grinding wheel and make slow, even passes across the wheel. The angle is crucial for maintaining the drill bit’s performance, so be precise.
4. Check the Angle: Use a protractor or a special angle gauge to ensure that the cutting edge remains at the correct angle throughout the sharpening process. Adjust the angle as needed.
5. Grind the Flutes: Once the cutting edges are sharpened, move on to the flutes. Hold the drill bit at a 90-degree angle to the grinding wheel and grind the inside of the flutes. This will help to remove any burrs and improve chip removal.
6. Hone the Cutting Edges: After grinding, use a fine sandpaper or a polishing cloth to hone the cutting edges. This step will remove any remaining burrs and give the edges a smooth finish.
7. Test the Drill Bit: Before using the sharpened drill bit, test it on a piece of scrap metal to ensure that it is cutting properly and that the angle is correct.
8. Clean and Store: Once the drill bit is sharp and tested, clean it thoroughly and store it in a dry, cool place to prevent rust and corrosion.
Conclusion
Sharpening metal drill bits is a straightforward process that can be mastered with a bit of practice. By following these steps and using the right tools, you can extend the life of your drill bits and maintain their performance. Remember to always prioritize safety and take your time to ensure the best results.
