Contents

• Can you sharpen carbide drills as well as HSS drills?
• How often should you sharpen drill bits / how to know when to sharpen drill bits?
• How to use a drill sharpening machine?
• Are drill sharpening machines worth it?
• Summary

Solid drills can be sharpened by hand using a bench grinder or a belt sander.

When sharpening drills by hand, it is important to maintain the correct drill point angle and to make sure the flutes remain the same length. Alternatively, a dedicated drill sharpening machine can be used which takes away the element of manually trying  to maintain the correct drill point angle. After sharpening a drill, a honing stone or some fine grit sandpaper can be used to remove any burrs.

Can you sharpen carbide drills as well as HSS drills? 

Both HSS and carbide drills can be re sharpened: the sharpening process remains the same for both substrates. When deciding whether HSS drills should be sharpened by hand, it is worth considering if this is the most cost-effective option. Due to the low cost of HSS, it’s sometimes cheaper to buy a new HSS drill. 

Carbide drills are more expensive, so re-sharpening can be a cost-effective option, although the only downside with this is the coating will be removed during the re sharpening process. If the drills are not recoated this will shorten the tool life.       

How often should you sharpen drill bits / how to know when to sharpen drill bits? 

How often a drill needs re-sharpening depends on several factors:

• Dullness or a drop in performance - If you notice that the drill is not cutting as efficiently as before, or if it's producing more heat than usual, it might be a sign that the drill bit is dull and needs sharpening.
• Visible Wear - Examine the cutting edges of the drill bit. If you see visible wear, chipping, or rounding of the cutting edges, it's time to sharpen the drill.
• Poor Hole Quality - If the drill is creating an uneven or rough surface finish, it could be an indication that the cutting edges are not sharp and need attention.
• Increased Drilling Pressure - If drilling by hand and you find yourself applying more force or pressure than usual to make the drill cut, it may be an indicator that the drill bit needs sharpening.
• Material Being Drilled - Harder materials like metals and alloys can dull a drill bit more quickly than softer materials like wood or plastic. For drilling on harder materials, the drill will need re sharpening more often.
• Coolant Issues - If you are drilling with coolant, and you notice that it's not as effective in keeping the temperature down, it could be due to a dull drill bit rubbing rather than cutting and causing too much friction.

How to use a drill sharpening machine? 

Using a drill sharpening machine involves several steps to ensure proper sharpening. 

Below are general guidelines for using a typical drill sharpening machine. Keep in mind that the specific instructions may vary depending on the model and type of sharpening machine you have. Always refer to the manufacturer's instructions for your specific sharpening machine. 

Prepare the Drill Sharpener
Set up the drill sharpening machine on a stable and level surface.

Select the Correct Grinding Wheel
Choose a grinding wheel suitable for the type of drill bit you are sharpening. Different materials and drill bit types may require different grinding wheels

Adjust the Machine Settings
Set the drill bit angle according to the manufacturer's recommendations or the specifications of the drill bit you are sharpening. This is typically done by adjusting the angle on the machine.

Secure the Drill Bit
Use the machine's chuck or collet to secure the drill bit in place. Ensure it is held firmly and centred. 

Adjust the Grinding Depth
Adjust the grinding depth on the machine. This determines how much material will be removed from the drill bit during sharpening.

Sharpening the Drill Bit
Gently bring the drill bit into contact with the grinding wheel. Move the drill bit across the wheel while maintaining a consistent angle, paying attention to the grinding process, ensuring even sharpening on both cutting edges.

Inspect and Test
After sharpening, inspect the drill bit for a sharp and even cutting edge. Test the sharpened drill bit on a scrap piece of material to ensure it performs as it should.

Are drill sharpening machines worth it? 

Drill sharpening machines offer several advantages over traditional manual sharpening methods. 

One significant advantage is the precision and consistency provided by drill sharpening machines. These machines are designed to maintain accurate angles and geometries, ensuring uniform sharpening for optimal drill performance. 

They also save time and effort compared to manual methods, as the grinding process is automated and efficient. 

However, the initial cost of a drill sharpening machine may be a drawback for some users, especially those with occasional sharpening needs. 

Additionally, there is a learning curve associated with mastering the use of the machine

Traditional methods, such as manual sharpening with a bench grinder, may be preferred by individuals who prioritise cost-effectiveness and have the skills to achieve consistent results manually. 

Ultimately, the decision to use a drill sharpening machine or traditional methods depends on the user's budget and frequency of use.

Summary

Resharpening drills instead of purchasing new ones can be a cost-effective option in the long-term. By maintaining and sharpening existing drill bits, engineers can significantly reduce the frequency of replacing worn-out tools, saving money over time. Quality drills can be expensive, and resharpening allows users to extend their lifespan, maximising the value of their initial investment. Regular resharpening also ensures that drills consistently deliver optimal performance.