How to Use a Spade Bit

Spade bits are among the most popular wood-boring drill bits. Also known as paddle bits, spade bits offer numerous advantages for cutting and drilling in woodworking. Known for their aggressive cutting action and efficiency, they are an essential tool for many DIYers and professionals.

In this guide, we'll explain how to effectively use a spade bit to achieve clean and accurate holes.

When to Use a Spade Bit

While spade bits are incredibly versatile, they truly shine in specific applications. They are ideal for rapid material removal when drilling larger holes for plumbing or electrical wiring, or for creating through-holes in framing lumber. Their aggressive cutting action makes them efficient for rough boring where a perfectly clean exit hole isn't the primary concern, such as behind walls or in unseen areas. For tasks demanding speed and a straightforward approach to creating wider holes, a spade bit often outperforms other drill bit types like twist bits or even Forstner bits, which are better suited for precise, flat-bottomed holes.

Understanding the Spade Bit

A spade bit is known for its speed and efficiency in drilling larger holes. They usually have a long shank, making them ideal for deep drilling. Spade drill bits feature two sharp cutting lips, outer spurs (on most designs), and a central pilot point for effective drilling into wood.

4 Easy Steps to Use a Spade Bit

Follow these simple steps to use a spade bit effectively:

Step 1 - Mark Your Workpiece

Before you begin drilling, mark the precise center point of your desired hole with a marker. This will help you drill an accurate hole in the wood. Crucially, make sure your workpiece is securely clamped with a clamp or vice to prevent movement and ensure safety.

After marking your workpiece, firmly place the shank of the spade bit into the drill chuck and tighten it.

Step 2 - Set Drilling Speed

It's essential to use a drill/driver that allows for adjustable speed settings. Refer to the below-mentioned spade drill bit speed chart to determine the optimal drilling speed:

When drilling through acrylic, make sure that your spade bit has spurs attached. Experts do not recommend using spur-less spade bits on acrylic, as they cannot create precise holes and may cause melting or chipping. Another essential point to consider while drilling through acrylic is speed. Do not exceed the recommended speed (500 RPM), as acrylic material can melt at higher RPMs.

Read More: Spade bit vs Drill bit

Step 3 - Drilling the hole

Align the pilot point of the spade bit with your marked center point, and then adjust the drill's angle so it is perpendicular to your workpiece.

To begin drilling, switch on the power and allow the drill bit to start rotating at a low speed. Maintain a firm grip on the drill. If the bit shifts off the marked point while drilling, it can quickly damage your workpiece or cause kickback.

As soon as the pilot point of the spade bit firmly engages the wood, gradually increase the drilling speed according to the chart. Allow the drill bit to rotate at the appropriate speed until it is about to break through the opposite side of your workpiece.

You have successfully drilled the hole. Now, carefully remove the drill bit from the borehole. Remember, the speed of spade bits means that maintaining a secure grip and following all safety measures is crucial.

Step 4 - Cleaning the hole

Finally, to help clean the hole and remove any excess material or tear-out, allow the drill to run at a low speed while slowly withdrawing the bit from the borehole. If the hole remains messy or shows significant tear-out, reinsert the drill bit at a low speed and run it through the hole 2-3 times, slowly withdrawing each time, to further clean and smooth the edges.

To get the best drill bit set for wood and metal, visit our store.

Read More: Spade bit vs Hole saw

How to Minimize Tear-out With a Spade Bit

While it's challenging to eliminate tear-out with spade bits due to their aggressive cutting action, there are effective methods to reduce it significantly:

• Secure Your Workpiece: Ensure your workpiece is entirely stable and cannot vibrate while drilling. Always secure it firmly with a clamp or vice.
• Use a Sacrificial Backer Board: Always place a sacrificial piece of scrap wood directly behind your workpiece. This "backer board" provides support as the bit exits, significantly reducing tear-out and protecting your workbench.
• Reduce Speed at Breakthrough: Before the drill bit entirely breaks through the opposite side of the workpiece, minimize the drilling speed. Reducing the speed just before exiting can greatly minimize tear-out.
• Drill from Both Sides: For the cleanest holes, drill from one side until the pilot point just emerges on the opposite side. Then, flip the workpiece over and finish the hole by drilling from the backside. This creates clean entry and exit holes.

Troubleshooting Common Spade Bit Issues

Even when using proper technique, you may still face common challenges.  If your spade bit wanders at the start, ensure your pilot point is firmly seated and consider starting at a very low RPM. If the wood appears to be burning during drilling, it likely indicates a speed that is too slow for the material, a dull bit, or insufficient pressure. Increase RPM within the recommended range, sharpen your bit, or apply more consistent pressure. Excessive vibration often points to an unsecured workpiece or an unbalanced drill; always double-check your clamping setup. Addressing these minor issues ensures a smoother, safer drilling experience.

Maintenance and Longevity

To ensure your spade bits perform optimally for years, proper maintenance is key. Regularly inspect your bits for dullness, especially the cutting lips and spurs. A dull drill bit requires more force, generates more heat, and produces inferior results. You can easily sharpen your drill bits using a mill file, a bench grinder, or a dedicated drill bit sharpener, focusing on the cutting edges. After use, clean the bit of any resin or debris and store it in a protective case to prevent damage.

Conclusion

You are now well-equipped with the proper method for using a spade bit effectively and safely. By following these steps and tips, you can achieve clean holes for your woodworking and home improvement projects.

You may also be interested in:

• What is a spade bit
• Paddle bit vs spade bit