Hand saws have been used to cut wood for centuries and they remain among the most popular tools used by woodworkers, construction workers, and DIYers. A good hand saw will cut through wood quickly and accurately, but it won’t be effective if it has blunt teeth.
Before you look to replace your hand saw, you should consider sharpening it instead. Sharpening a saw is a simple task and will help you use your tool for longer, but you might need some advice if you have never done it before.
To help you do it properly, we will explain how to sharpen a hand saw. By following these tips, you should be able to get your saw cutting like the first time you used it.
- Choose the correct file: Use a tapered file that matches the hand saw’s teeth per inch (TPI) for effective sharpening.
- Inspect and level the teeth: Ensure all teeth are even before sharpening, also known as jointing, to achieve a smooth and uniform edge.
- Sharpening technique: For rip-cut saws, hold the file perpendicular to the blade, using smooth strokes. For crosscut saws, place the file at a 15-degree angle and follow the bevel of the teeth.
- Regular maintenance: Store the hand saw in a moisture-free toolbox, oil the blade, remove any rust, and use the correct saw for each task to prolong its life and cutting efficiency.
Types of Hand Saw Teeth
There are two main types of hand saw teeth, which have different alignments but are both designed to cut through wood.
Crosscut teeth are angled on the inside edge to make them more effective at cutting across the fibers of the wood. These teeth essentially act like a series of many tiny knives, gradually slicing through the wood. These saws are designed to cut across the grain, hence their name, which is more difficult than cutting with it.
Rip-cut teeth don’t have an angled edge, unlike crosscut teeth. Instead, the teeth act like chisels, scraping away the wood as they move along the material. These teeth rip through the wood along the grain, which is easier than cutting across it.
How to Choose a Saw File
Saw files are available in four basic tapers: regular, slim, extra-slim, and double extra-slim. They also vary greatly in quality. Cheap, imported files are generally made of softer materials, which won’t file as effectively and won’t sharpen your saw properly. If you want to save money by extending your hand saw’s lifespan, it is worth paying a little extra for high-quality files.
When choosing a file, try to use one that isn’t too big or too small. You should be able to see the teeth of the blade as you file and there shouldn’t be any underlap or overlap of either edge of the file.
A file that is too small won’t be able to sharpen each tooth evenly, which could end up dulling the saw instead of sharpening it.
On the other hand, a file that is too large will obscure the teeth and prevent you from seeing what you are doing. As a result, they rarely deliver the same level of sharpness as smaller files.
You can determine the size of the file you need by looking at the saw’s teeth per inch.
This chart should help:
|File Type||Teeth Per Inch (TPI)|
|8-inch regular taper||3 to 4.5|
|6-inch regular taper||5 to 5.5|
|7-inch slim taper||6 to 7|
|6-inch slim taper||8|
|6-inch extra-slim taper||9 to 10|
|6-inch 2x slim taper||11 to 13|
|4-inch 2x slim taper||13 to 20|
What You Need
- A set of taper files
- A saw set
- A vice
- Spare wood
- A mill file
How to Sharpen a Crosscut Saw
1. Inspect the Saw
Before you start filing, make sure all of the teeth are level. If there are variations in the teeth, you will need to make them level again. This process is known as jointing. Clamp the saw into the vice and use two strips of wood to support the blade and add rigidity.
Make sure the teeth protrude 2 inches above the top of the vice. Grab your mill file and start from the heel end of the blade, moving the file along the tooth line toward the toe. This should even out the teeth, leaving you with a uniform edge. Use three or four strokes to perfect the line.
The benefit of jointing is that it creates a flat edge along the tips of the teeth to guide your file when you start sharpening the saw blade.
2. Set the Teeth
Saw sets are tools that resemble pliers with long handles at one end and a clamp at the other end. A winding mechanism aligns the blades when you squeeze the handles together. You should see the tooth moving if it was previously out of alignment.
Place the saw set so the center hammer (the metal winding mechanism that bends the tooth against the anvil) is aligned with the point of the tooth and then squeeze the handles. The tooth should move away from you. Repeat this process on every other tooth, then turn the blade around and work along any teeth that you missed on your first pass.
3. Put on Your Safety Equipment
Put on your safety goggles and reclamp your saw in the vice. Make sure the bottoms of the tooth gullets are 0.063 inches above the top of the vice. Now place the taper file between the first pair of teeth. You should have teeth on both sides, with one facing you from the right and another facing away to the left.
4. Start Filing
Press your index finger firmly on the file at the point where it meets the tooth, then push the file down into the gullet. This should rotate the file into the gullet at an angle that matches the 15 degrees of the crosscut teeth.
Maintain the bevel angle and make your first stroke, ensuring the file stays in the gullet. Your aim is to reduce the flat area on the front and back teeth by half.
5. Skip the Next Tooth
Skip a gullet and repeat the sharpening process, using the same number of strokes. You are skipping a tooth because they are in alternating directions. When you reach the end of the blade, you can start with the first gullet you skipped and work along the blade in the same manner. Just make sure the teeth on the left are facing toward you and those on the right are facing away.
To achieve the highest-quality finish on the blade, you will need a block of India stone at 600 grit. With the saw placed flat on your table, gently run the stone along its edge. This will remove any burrs created by the filing process.
Flip the blade over and do the same to the other side and your saw should be ready to use.
Test Your Blade
How to Sharpen a Rip-Cut Saw
1. Clamp the Saw
Clamp your saw to hold it in place while you work, using two strips of wood to support the blade in the clamp. You should set the height of the gullets at 0.063 inches above the top of the vice. Make sure the saw’s heel is to your right.
2. Place the File in the First Gullet
Place the file in the first gullet, ensuring it is firmly seated at the bottom. Hold the file perpendicular to the saw blade, so it is parallel to the table.
3. Start Filing
Apply gentle pressure and push the file across the saw blade to make your first stroke. Use the full length of the file for more efficient sharpening.
4. Make Fluid Strokes
Novices have a tendency to use short, jerky strokes but these often result in an uneven finish. You should use long, smooth strokes with consistent pressure, using the same amount of passes in each gullet of the saw.
When you pass the file across the gullet, you should see fresh steel on the front and back of the teeth on each side of the gullet, as well as in the gullet itself.
Continue filing until you can’t see the flat area on the right anymore. When you are satisfied, move on to the next tooth and repeat the process. Work along the blade until you reach the end.
Hand Saw Maintenance Tips
Maintaining your hand saw should prolong how long you can use it before it needs to be re-sharpened. Here are some tips that will help you slow the dulling process and preserve your saw’s integrity.
Store in a Moisture-Free Toolbox
Moisture causes rust and rust damages metal objects such as your hand saw’s blade. The best way to prevent corrosion is to keep your saw in an airtight toolbox where humidity won’t get at it.
Oil the Blade
Oiling your blade between uses will protect it against moisture and keep rust at bay. It will also lubricate the saw, which helps it cut more smoothly.
You can remove rust on your blade by using either a razor blade or sandpaper. Both options will scrape away the layer of corrosion and leave you with a smooth blade.
Use the Saw Correctly
Use long strokes when making cuts with your saw. This will be smoother and exposes the teeth to a more even amount of wear and tear. Doing this consistently will prevent your saw from becoming blunt in one area alone.
Use the Correct Saw
Choosing the wrong saw for a task is a surefire way to damage its teeth. If the material is too hard, you will dull the cutting edge very quickly.