Sharpen Spade Bits 3 Ways

Learn how to sharpen spade bits or other types of bit for that matter. In the long run you’ll save a ton of money that can be spent on other materials or tools. For someone new to wood working there’s an easy and affordable way to dress up a dull spade bit.

On this page you’ll learn how it can be done with 3 different methods including step by step instructions and videos.

Spade Bit Having a Hard Time Drilling Through Wood?

If your spade bit won’t bore through wood there’s a good chance that it needs to be sharpened. Some of the signs of a dull spade bit are vibration and chatter.

The inside of the hole that’s drilled looks like it’s been burned is another indication that the bit has lost its edge.

When drilling you find that you have to add more pressure on the back of the hand drill to get it to cut. Same thing with a drill press when adding more than normal pressure on the handle that lowers the bit when drilling. 

How Do Spade Bits Get Dull

They mainly get dull through use. Since they move at a rapid speed, the spade bit goes through a lot of friction which causes the cutting edge to get dull after a while. 

It doesn’t matter what type of drill bits you have, they all will get dull. Bits that are made from high speed steel will keep their edge longer but in the end even those have to either be replaced or sharpened.

There are some things that can cause a spade to get dull faster than others. Boring holes through hardwoods will dull it faster than going through softwoods.

Drilling through wood that has nails, screws or staples will definitely cause your spade bits to lose their edge or become damage altogether. If you’ve hit one of these obstructions, then there’s a good chance that a nick has been taken out of the cutting edge.

Are Spade Bits Worth Sharpening?

Yes, spade bits are worth sharpening. Even though they’re inexpensive, why waste the money when the edge can easily be resharpened. Learning how to sharpen your spade bits and other tools is a valuable technique to have. 

Learning the basics on how to sharpen them isn’t difficult to learn. It just takes a little patience and time to do it right.

Methods for Sharpening a Spade Bit

Spade bit file method: There Are several methods that spade bits can be sharpened. The easiest and least expensive way is through the use of bench vice, a few pieces of scrap wood and a narrow flat file such as a needle file or an auger file. The auger file is the one that I would recommend. 

Using this type of file is pretty versatile and is designed to be used on spade bits and others. 

If you have spade bits that have spurs, the file method is a good choice since filing won’t remove the spurs but can be used to sharpen them as well. 

Step 1: Put the shank of the spade bit between the scrap pieces of wood in the vice so that the shank doesn’t get damaged when you go to tighten down on it. The shank of the bit should be all the way down in the vice to where just the spade part of the bit is showing.

Step 2: Take your file and lay it on the beveled part of the spade and move the file up and down. What this does is help to find the correct angle before you actually start to file. 

Step 3: Once you’ve found where the file lays flat on the bevel, it’s just a matter of moving your file in forward strokes to get the edge back to where it will cut.

The important thing is to count the strokes so that the entire spade bit gets the same amount of attention. You don’t want the bit to become unbalanced. This technique works on the spur part of the bit and the point.

Spade bit sharpening using a file

Sharpen spade bits using a grinder: Using a bench grinder is another common method for sharpening spade bits. It’s a pretty good all around investment for the workshop since it can be used for other things

Using the bench grinder is faster than using the file method but some things do need to be taken into consideration.

The first being you don’t want to hold the bit on the grinding wheel too long. This causes the bit to heat up too much to where it will lose its temper. Too much heat ruins drill bits. 

If your spade bits have spurs, keep in mind that they will be ground off. There is no way to sharpen spurs using a bench grinder. Spurs on a bit are more of a luxury than a necessity. They just provide a smoother hole when boring but not by much.

The next thing to consider is keeping the bit balanced. Count how many seconds you grind so that you can apply the same amount of time to the other parts of the bit.

For this process you’ll want a cool running grinding wheel. The factory grinding wheels that come with a bench grinder are too abrasive which builds up a lot of heat.

Step 1: The angle of the bevel of a spade bit is 5 degrees down from the center of the grinding wheel so lower the tool rest that point. Don’t worry too much if it’s a little off just as long as you keep it close to that.

Step 2: Lay the flat part of the spade on top of the tool rest with the cutting edge of the bit facing you. If you don’t see the cutting edge, it’s upside down. 

Step 3: You’ll be working on the right hand wheel and on the right hand side of that wheel. Slightly touch the bit to the grinding wheel while running. Don’t push too hard, just touch the bit to the wheel. Once you see a shiny edge, flip the bit over and repeat the process.

Sharpening spade bits with a bench grinder

Drill Bit Sharpener for Spade Bits

Drill bit sharpeners is the last method that you can choose from. It’s also more expensive than the file and bench grinder method. However it does excel at saving time plus it takes all of the guesswork out of figuring out what angle to grind spade bits and other drill bits. 

Spade bit drill sharpener

Is a Drill Bit Sharpener Worth it?

Well that depends on your circumstances. If you have a lot of drill and spade bits that you use a lot. Then yes, it’s a good investment and saves a lot of time. It will also pay for itself since you won’t be buying spade bits as often as you might have.

If you don’t need to sharpen them often because you don’t use them often, then probably not. The file method or the bench grinder will work fine.

Reference:

sharpen spade bits using a file

sharpen spade bits using a bench grinder

sharpen spade bits with a drill bit sharpener