Lubricate Drill Bits Correctly for Longer Tool Life and Better Results
Introduction to Drill Bit Lubrication
Proper lubrication is one of the most overlooked aspects of drilling that can dramatically improve your results and extend the life of your drill bits. Whether you’re a DIY enthusiast or a professional craftsman, understanding how to correctly lubricate your drill bits can save you time, money, and frustration. The right lubricant reduces friction, prevents overheating, improves cutting action, and helps achieve cleaner, more accurate holes. This article will guide you through everything you need to know about selecting and applying the right lubricants for different materials and drilling applications.
Why Lubricating Drill Bits Is Essential
When drilling, friction between the bit and the material generates heat. Excessive heat can:
1. Dull or damage the cutting edge of your drill bit
2. Cause the bit to break during operation
3. Create rough, inaccurate holes
4. Burn or damage the material being drilled
5. Reduce the overall lifespan of your drill bits
Proper lubrication addresses these issues by:
– Reducing friction between the bit and material
– Dissipating heat generated during drilling
– Improving chip evacuation
– Enhancing cutting efficiency
– Providing smoother, more precise holes
Essential Tools and Materials for Drill Bit Lubrication
Before drilling any material, make sure you have the appropriate lubricants and accessories on hand:
| Lubricant Type | Best Used For | Application Method |
|---|---|---|
| Cutting oil | Steel, iron, and most metals | Brush or spray |
| WD-40 | Aluminum and softer metals | Spray |
| Kerosene | Aluminum and some plastics | Brush application |
| Beeswax or paraffin | Wood and some plastics | Rub directly on bit |
| Water or water-based coolant | Glass, tile, and masonry | Spray bottle or sponge |
| Cooking spray (like PAM) | Emergency substitute for light-duty work | Spray |
Choosing the Right Lubricant for Different Materials
Drilling Metal
Contrary to some misconceptions, using the right lubricant when drilling into metal is crucial for success. As one machinist noted, “Don’t use oil when drilling into steel. You’ll break the bit” is actually incorrect advice. The truth is that proper lubrication is essential for metal drilling.
For steel and iron:
– Cutting oil is the gold standard
– Apply generously before and during drilling
– Reduce drilling speed for better results
– Periodically reapply when drilling deeper holes
For aluminum:
– WD-40 or kerosene works exceptionally well
– As one user mentioned, “a little bit of the right lubricant can do wonders for the cutting edge on a drill bit. WD40 or kerosene work well on aluminum.”
– Apply frequently as aluminum can heat up quickly
For brass and copper:
– Light machine oil or specialized copper cutting fluid
– Apply moderately, as these metals are generally easier to drill
Drilling Wood
While wood doesn’t typically require lubrication, there are exceptions:
– For hardwoods: A light application of beeswax or paraffin on the bit can reduce friction
– For resinous woods (like pine): A small amount of beeswax prevents pitch buildup on the bit
– For deep holes: Periodically withdraw the bit to clear chips and apply a small amount of wax
Drilling Glass, Tile, and Masonry
These materials require water-based cooling rather than oil-based lubrication:
– Use clean water or a water-based coolant
– Keep the drilling area wet throughout the process
– Consider creating a small “dam” around the drilling area to contain water
– For glass especially, start slowly with very light pressure
Drilling Plastics
Plastics require special consideration:
– Use a water-based lubricant or specialized plastic drilling fluid
– Avoid petroleum-based products that might damage certain plastics
– Keep drilling speed low to prevent melting
– Apply lubricant frequently to dissipate heat
How to Properly Apply Lubricant When Drilling
Follow these steps for effective lubrication during drilling:
1. Prepare your work area to contain any mess from lubricants
2. Mark your drilling location precisely
3. Apply lubricant to the drilling spot before starting
4. Begin drilling at a slow speed
5. For deeper holes, periodically withdraw the bit and reapply lubricant
6. Clear chips regularly to prevent clogging and overheating
7. For through-holes, reduce pressure as you near breakthrough
Timing Your Lubrication
Knowing when to apply lubricant is just as important as using the right type:
– Initial application: Before the drill bit touches the material
– Ongoing application: Every 10-15 seconds for continuous drilling
– Depth-based reapplication: Every 1/4 inch of depth for harder materials
– Temperature check: If the bit feels hot to touch, stop and reapply lubricant
DIY and Improvised Lubricants
When commercial cutting oils aren’t available, you can use these alternatives:
– Cooking spray (like PAM): Works surprisingly well for light-duty metal drilling
– Vegetable oil: Can substitute for cutting oil in a pinch
– Dish soap mixed with water: Effective for glass and tile
– Candle wax: Can replace beeswax for wood drilling
As one machinist noted in a forum, “It is amazing how many different materials can be successfully deployed in metal removal – I use Pam for machining (turning, drilling, milling).”
Common Mistakes to Avoid
Avoid these common errors when lubricating drill bits:
1. Using the wrong lubricant for the material
2. Applying too little lubricant (especially on metals)
3. Drilling too quickly, which generates excessive heat
4. Failing to reapply lubricant during deep drilling
5. Using oil-based lubricants on materials that require water cooling
6. Not clearing chips frequently enough
7. Applying lubricant after the bit has already overheated
Troubleshooting Common Drilling Problems
Problem: Drill Bit Breaking
– Possible cause: Insufficient lubrication causing overheating
– Solution: Use more lubricant and drill at a slower speed
– Prevention: Start with a pilot hole and apply lubricant before and during drilling
Problem: Rough or Inaccurate Holes
– Possible cause: Inadequate lubrication causing the bit to wander
– Solution: Ensure proper lubrication and use a center punch to mark the starting point
– Prevention: Start with a smaller pilot hole and maintain consistent lubrication
Problem: Bit Dulling Quickly
– Possible cause: Excessive heat due to poor lubrication or too high speed
– Solution: Increase lubrication frequency and reduce drilling speed
– Prevention: Use the correct lubricant for the material and maintain proper drilling technique
Problem: Material Burning or Discoloring
– Possible cause: Excessive friction and heat
– Solution: Increase lubrication and reduce drilling speed
– Prevention: Use sharp bits and appropriate lubricant for the material
Special Considerations for Different Drill Bit Types
Different types of drill bits may require specific lubrication approaches:
HSS (High-Speed Steel) Bits
– Require consistent lubrication when drilling metals
– Benefit from cutting oil for ferrous metals
– Use lighter oils like WD-40 for aluminum
– Time estimate for drilling 1/4″ steel: 1-2 minutes with proper lubrication
Carbide Bits
– More heat-resistant but still benefit from lubrication
– Require less frequent lubrication than HSS bits
– Still need cooling when drilling harder materials
– Time estimate for drilling 1/4″ steel: 30-60 seconds with proper lubrication
Diamond-Coated Bits
– Used primarily for glass, tile, and stone
– Require water-based cooling, not oil lubrication
– Need constant cooling to prevent damage to the diamond coating
– Time estimate for drilling through 1/4″ glass: 2-3 minutes with proper cooling
Center Drills and Specialized Bits
As one jewelry maker noted, “Buy a center drill of the correct size from MSC or some other machine… cutting oil and slow the speed of the drill down, the bits should [last longer].”
– Center drills benefit from cutting oil when creating starter holes
– Specialized bits often come with manufacturer recommendations for lubrication
– Follow specific guidelines for bits designed for particular materials
Maintaining Your Drill Bits After Use
Proper care after drilling extends bit life:
1. Clean bits thoroughly after use to remove any lubricant residue
2. Wipe metal bits with a light oil to prevent rust
3. Store bits in a dry environment
4. Inspect bits regularly for wear or damage
5. Sharpen bits as needed to maintain cutting efficiency
Conclusion: The Impact of Proper Lubrication
As BLACK+DECKER notes, “Lubricating the drill bit and drilling material extends the bit’s life and improves cutting action, accuracy and hole quality.” This simple practice makes a significant difference in your drilling results and tool longevity.
Remember that the right lubricant depends on both the bit material and the material being drilled. Taking a few extra moments to apply the proper lubricant will save you time, money, and frustration in the long run by preventing broken bits, poor-quality holes, and damaged workpieces.
By following the guidelines in this article, you’ll be able to drill more efficiently, achieve better results, and extend the life of your valuable drill bits. The small investment in proper lubricants and the time taken to apply them correctly will pay dividends in your drilling projects for years to come.