How to Sharpen Hand Saws for Woodworking

//How to Sharpen Hand Saws for Woodworking

In the above video I filmed hand saw maker Tom Calisto sharing a tutorial on how to sharpen new and antique hand saws for woodworking. Sharpening hand saw teeth is a skill that takes time to develop, but a suitable hand saw sharpening job can be done after a couple tries, so don’t feel too intimidated. It just takes a little practice. Between Tom’s video and my article below we’ll try to simplify the process for you. This video tutorial comes from the upcoming DVD titled “Building an 18th Century Panel Saw with Tom Calisto” (click here to be emailed when it’s released). Before jumping into the hand saw sharpening tutorial, it’s important to first understand which sharpening tools you need for hand saw sharpening. We’ll also define and simplify some important concepts, such as tooth count, tooth shape, fleam, rake, and set.

Tools Required for Sharpening Hand Saws ~

1. Hand Saw Sharpening Vise

Metal antique hand saw sharpening vise

A special hand saw sharpening vise is used to hold your saw plate steady while you joint and file your hand saws. You can either make your saw vise or buy a new or antique hand saw vise. A shop-made hand saw sharpening vise can be as simple as some basic wooden jaws that clamp into your workbench vise, or as complex as wooden jaws with wooden screws (like Tom’s in the above video). Almost all shop-made hand saw sharpening vises that I’ve seen clamp into your workbench vise.

Wooden hand saw vise and Disston D-8 Rip hand saw in a woodworking workbench vise

You can find antique cast iron hand saw sharpening vises that work quite well (I own a couple), and are typically pretty affordable. However, they are usually not as long as a shop-made vise, so you’ll need to move your longer saws an extra time, which really isn’t that big of a deal. Most of these metal hand saw sharpening vises have a metal screw clamp which makes it easy to clamp to almost any surface, including a counter top or kitchen table. Above you’ll see the simple vise that I made for my longer hand saws. Here are some free saw vise plans and tutorials, and links to antique vises:

Antique Metal Saw Vises:

Wooden Saw Vise Plans & Tutorials:

2. Triangular Hand Saw Sharpening Files and handles

hand saw sharpening triangular files

Triangular hand saw files are used to shape western-style hand saw teeth. These triangles are 60 degrees on each angle, so the space between your saw teeth will always be 60 degrees. The size of saw file to purchase depends on the size of the teeth on your hand saw (or the size of the teeth that you’re going to create). Smaller hand saw teeth (more teeth per inch) would require a smaller triangular file, while larger saw teeth require a larger triangular file.  Pretty simple, huh? There are many charts to help you determine which size hand saw file is needed, but if you ever mix up your triangular saw files, just realize that you need each side of your triangular file to be twice the size of the saw tooth.

Triangular hand saw file filing rip hand saw teeth

This will help you conserve your files and money because it allows you to use up both halves of a file side. Even though all files have the same 60 degree shape, using files that are too big will miss shape your teeth, because they have rounded edges, rather than sharp edges as found on small files. Here is a chart of recommended triangular hand saw file sizes (you can, of course, be a little flexible):

Recommended Triangular File Sizes
PPI File Size
4 – 5 1/2 7-in. regular taper
6-7 7-in. slim taper
8 6-in. slim taper
9-10 6-in. extra slim taper
11 6-in. double extra slim taper
12-14 5-in. double extra slim taper
15-20 4-in. double extra slim taper

Not all triangular hand saw sharpening files are made to the same quality. Some of them wear out much faster than others. Here are some file brands that I’ve used and some that have been recommended to me by other woodworkers and hand saw sharpeners:

Bahco saw files:

Grobet saw files (also branded as “Vallorbe” and “Glardon” in some areas):

Simonds saw files:

Nicholson saw files:

Nicholson’s quality isn’t what it used to be, but some people still like them…

3. Hand Saw Sets

Veritas hand saw set for sharpening

A hand saw set is used to slightly bend each tooth to give clearance so a hand saw won’t bind up in the wood. Stanley made some popular hand saw sets, including the No. 42 and No. 42X pistol grip saw sets. Tom loves the antique No. 42X and I really like the new Japanese Somax No. 250 saw sets. You can find them all here:

4. Hand Saw Sharpening File Guides

Veritas hand saw file guide holder laying on a woodworking workbench

To accomplish uniform saw filing, it’s important to hold the triangular saw file at a consistent angle for each hand saw tooth. This can be accomplished as simply as attaching a small block of wood to your triangular saw file, or as sophisticated as using a store-bought hand saw file guide that fits on the end of your triangular saw sharpening files. I’ve used both methods over the years, and can admit that I really love using a commercial file guide. I own the Veritas / Lee Valley’s file guide.

5. Bastard Mill File & Saw Jointer

Jointing hand saw teeth with a saw jointer and bastard mill file

A bastard mill file is ideal for jointing (i.e. flattening/leveling) the tops of the hand saw teeth so they are all a uniform height. The mill file needs to be held at 90 degrees to the saw plate so that the teeth are square to the saw plate’s face. The mill file can either be held in a wooden block or in a metal file holder. Here an example of an antique hand saw jointer and file:

Antique hand saw sharpening jointer and file

Click Here to buy the hand saw jointer and mill file that I own.

6. Magnification & Lighting

Filing and setting small hand saw teeth can be difficult to see, so many woodworkers use some sort of magnification solution. These solutions can include a magnifying lamp that sits on your workbench (best option), reading glasses, or even a magnifying headset. A closeup light source, like a lamp or a sunny window, is imperative. A movable and flexible lamp is especially helpful.

Magnification head lamp for hand saw sharpening

7. Protractor

General Protractor for woodworking

A protractor is very useful for generating your desired saw tooth geometry angles. For example, I use a protractor to set the fleam angle so I can draw visual guides on some painter’s tape which I apply to my hand saw sharpening vise. I own this General Tools 17 Square Head Metal Protractor (buy it on Amazon).

~ HAND SAW TOOTH COUNT OR “PITCH”~

Hand Saw tooth count number eight (8) stamped into steel hand saw plate

The number of saw teeth per inch (or points per inch) is also called the “pitch”, and is another important factor in selecting a hand saw for a particular purpose. Large hand saw teeth will cut quickly through the wood, but can leave a rough surface. Small hand saw teeth will cut finely and accurately, but are not practical for cutting long lengths or widths.

When dealing with normal hand saws or frame saws, “Rip” teeth are typically larger than “Cross Cut” teeth. In back saws, rip and cross-cut teeth can vary in size. The number of teeth per inch are usually expressed as “points per inch” (ppi) or “teeth per inch” (tpi) and the number is often stamped into the saw plate (see the above photo). However, you can change the tooth count during your sharpening. Many woodworkers would agree that for woodworking hand saws, there is no need for saw teeth smaller than 15 ppi. Here are examples of large (rough) and small (fine) hand saw teeth:

Lie-Nielsen brass back dovetail back saw with rip teeth

This photo shows a dovetail back saw with rip teeth filed to a tooth count of about 15 ppi.

Rip hand saw cutting down the grain of a piece of Southern Yellow Pine lumber

This photo shows a hand saw with rip teeth filed to a tooth count of about 5 ppi.

~ HAND SAW TOOTH SHAPE & GEOMETRY ~

Hand saw blades are usually sharpened to two different tooth configurations, “Rip” and “Cross Cut”. You can change any saw’s tooth shape with saw sharpening tools. There is also a hybrid hand saw tooth configuration that is in between a Rip and Cross-cut shape, called a “Sash” tooth configuration, which is useful if you can only afford one hand saw…but it’s not as proficient at either ripping or cross-cutting). Sash saws were historically used by window makers (e.g. window sash) who needed to cut many types of cuts and didn’t want to switch between two backsaws. Here are some tooth shape diagrams:

RIP SAW TEETH

hand saw rip teeth close-up detail

CROSS-CUT SAW TEETH

hand saw cross-cut teeth close-up detail

Hand saws with  “Rip” teeth will  cut along the length of the board’s grain (“ripping”). The tooth is shaped like a woodworking chisel, and pushes through the wood like a chisel.

Hand saws with  “Cross Cut” teeth cut across the grain (“cross cutting”). The tooth is shaped like a knife blade. It cleanly severs the wood grain, just as if you used a knife.

~ SHARPENING A WOODWORKING HAND SAW ~

Close-up view of Tom Calisto filing and sharpening hand saw teeth with a triangular saw file

Now that we’ve established tools needed for sharpening, tooth count, and tooth shape, let’s talk about sharpening hand saws. If you’ve got a cheaper hand saw to practice on, that would be helpful for practicing on before sharpening your favorite hand saw.

{Tip: These affordable “Gent’s Saws” are good to practice on, and can also do quite well as a primary backsaw after they’re sharpened}.

Sharpening a hand saw includes several steps, including jointing the saw teeth (leveling) filing the teeth (shaping), setting the teeth (bending), and stoning the teeth (Deburring). As always, there are many different great ways to sharpen a tool, and most of them work fine. Most methods include these same steps, but some people change the order of the steps. It would be arrogant to claim that this is the only acceptable way to sharpen a hand saw, but it works for many people.

Step 1: Joint the Saw Teeth (If Uneven)

Antique hand saw jointer and file flattening hand saw teeth

The first jointing of the hand saw teeth involves leveling the teeth to the same height with a file and holder. This file holder / jointer holds the file 90 degrees to the saw plate. If you are sharpening a hand saw with newly punched teeth that are all the same height, then you can skip this first saw jointing, since the teeth are already the same height. The same applies to any saw that you know has been properly sharpened recently. If you’re unsure if the teeth are the same height, then just lightly dust the top of the teeth with the jointer and file to expose a small shiny, reflective flat spot. Just make one or two light passes, from heal to toe, following the flow of the teeth. This will show if most of the teeth are all the same height. Certainly do not keep jointing to get every single tooth level. Some teeth may have been broken off or chipped, and jointing until you flatten these teeth would remove too much of your good teeth. Too many passes with the jointer will require too much work to reshape the teeth, which will unnecessarily wear out your files and waste your time. I speak from experience.

Step 2: Set the Hand Saw Teeth (If Needed)

Somax No. 250 Saw Set Tool setting teeth on a Henry Disston back saw

Setting the teeth involves adding a very slight bend to the teeth so that the saw plate doesn’t bind (or get stuck) in the kerf that’s being cut. Saws that need to cut aggressively (like for ripping through some green wood) would have more set than saws that need to cut more finely (like for cutting joints in dried hardwood). Many people save setting the teeth for later in the saw sharpening process, but setting them first makes it easier for you to see which tooth needs to be filed, especially on cross cut teeth. If your saw teeth look like they have already been set, then don’t set them again, unless your hand saw binds at the last step. If your hand saw has freshly punched teeth that have never been shaped or set before, then this step is especially applicable.

As a general rule, you would file the face of the tooth that is pointing away from you. A hand saw really only needs to be set about every 3-6 sharpenings (when the teeth get worn down, and the set becomes less wide). Otherwise setting too often can weaken and break saw teeth. Especially take care to never set, or bend a tooth in the opposite direction that it has already been set. This will more than likely break the tooth. Only the top 2/3 of the saw tooth will be set, and your saw set tool will keep you from setting more. If you set the saw teeth without a special tool, you will have to take extra care not to set too much of the tooth. Also pay extreme attention to make sure you set every other tooth in opposite directions.

Closeup view of Somax No. 250 Saw Set Tool setting teeth on a Henry Disston back saw with number dial

Saw setting tools have a small dial that determines how far the tooth will be bent away from you. It’s a good idea to use as little set as possible. After all, it’s easier to add more set later, than it is to remove set. For example, on the above photo “12” is the smallest amount of set. The instructions for these Somax saw sets say, “The adjustable hardened steel anvil on both models is graduated from 4 to 12. Contrary to popular belief, the numbers are not representative of the teeth per inch on the saw blade, but are rather gauges or indicators for repeatability.”

I use two saw setting tools: one for hand saws with smaller teeth and one for hand saws with larger teeth. Why? The “Standard” gold saw set (on the right) has a larger plunger, and is for larger saw teeth (from 4 to 12 tpi). The “Fine” blue saw set (on the left) has a smaller plunger and is better suited for smaller teeth (from 12 to 26 tpi) , like on dovetail saws and tenon saws (and other backsaws). These little metal plungers push the tooth against a little metal anvil. The metal anvil (with the numbers on it) restricts the bending of the tooth. The little plunger ideally should be no bigger than the base of the tooth that you’re trying to set. If it’s wider than the tooth, it probably won’t do a good job. Below you can see on my Somax No. 250 Saw Setting Pliers the size difference between the little metal plungers.

Blue Somax No. 250 fine hand saw set tool and Somax No. 250 gold hand saw set tool

Antique saw sets can be modified so that the little plunger is smaller (you can file it down).

Antique hand saw set setting teeth on a woodworking hand saw in a hand saw sharpening vise

Use the saw set on every other tooth, bending it away from you. Then flip the saw around, and bend every other tooth (that hasn’t yet been bent) and use the saw set tool to bend it away from you (in the opposite direction as the already-bent teeth). Here you can see a macro view of set teeth that have been bent in oposite directions:

Overhead macro view of hand saw teeth that have been set

If you have calipers, it can be helpful to measure the set. You can bend each tooth 1/5000 to 1/8000 of an inch per side. First, you can set about 1-inch of teeth closest to the heal of the saw (both sides) to test your set, and see how much set your set tool is giving you. Measure your saw plate thickness, then measure the total width of two opposing set teeth. Subtract the thickness of the saw plate from the total width of the two set teeth to give you the total amount of set for both teeth together. Divide that by two, and you will know the amount of set on each tooth. If it looks good, then proceed with setting the rest of the teeth. This, of course is an optional practice, and you can just see how the saw cuts to determine whether more or less set is required. Even a pretty dull hand saw will cut, so don’t wait to start sawing until you’ve perfected saw setting & sharpening.

To make the setting easier, look at the next tooth that you’ll be setting right before you skip a tooth to the next tooth. You can also use a Sharpie marker to mark a dot on every other saw tooth, to make sure you don’t set the wrong tooth. This is especially helpful on small hand saw teeth.

Step 3: Shape the Hand Saw Teeth (If needed)

Woodworking hand saw teeth rip saw and cross cut saw

The shape of the teeth determines the performance and use of the hand saw. No one tooth shape is the “best” shape, and different woods and different jobs require a different shape. For example, a rip tooth shape (as mentioned above) is better for cutting along the grain of the wood (like a chisel) and a cross cut tooth shape is better for cutting across the grain of the wood (like a knife). Several terms are imperative to understand if you want to shape your hand saw teeth correctly for your given job:

Rake Angle

Sharpening filing hand saw teeth rake example

As the above graphic shows, rake is the angle that the file slopes back from 90 degrees. Both rip saws and cross cut saws can have rake. Rip saws generally have 0-8 degrees of rake and Crosscut saws generally have between 8-15 degrees of rake. A 90 degree, vertical tooth would have zero degrees of rake. The less rake a hand saw has, the more aggressive it cuts, but the harder it is to start and cut. Laying the tooth back a bit with a slight rake angle will make the cutting easier, but less aggressive. A high amount of rake will move really smoothly through a cut, but it won’t cut aggressively. Balance is key. Ideally you would have multiple rip-toothed hand saws and multiple crosscut-toothed saws (like some people do) and have different tooth geometry for different jobs. But most people will only be able to afford a few hand saws. So there are some good general purpose recommendations for the most common types of work. Here’s a chart to help you decide which rake angle to add to your hand saws when shaping the teeth:

Crosscut Saws Rip Saws Back Saws
Softwoods 8-15 degrees  0-6 degrees 12-16 degrees
Hardwoods  8-15 degrees 6-10 degrees 12-20 degrees

A 12 degree rake angle is a popular angle for crosscut saws.

Fleam Angle

Sharpening filing hand saw teeth fleam example

Fleam is the angle at which you would file across the saw. A zero degree (or very minor) fleam is used on rip saws and the triangular file sits perpendicular to the saw. As soon as the file is turned left or right, fleam has been introduced. Fleam is typically only used for crosscut saws, as it is what creates the knife shape on the teeth. Here’s a chart to help you decide what fleam angle you may want to add to your hand saws when shaping the teeth:

Crosscut Saws Rip Saws Back Saws
Softwoods 20-25 degrees 0-6 degrees 20-30 degrees
Hardwoods 15-20 degrees  0-6 degrees 15-30 degrees

The fleam angle can be drawn right on the saw vise, on tape, or on a piece of paper that sits right below your saw vise. With the paper guide, you can move the paper along the workbench as you progress down the saw teeth.

Sharpening a cross cut hand saw with a 20 degree fleam drawn on paper below a wooden hand saw sharpening vise. Triangular saw file held at 20 degrees.

A popular fleam angle for most woodworkers is between 15 and 20 degrees. You can download my free printable PDF sharpening guides here:

The Veritas saw filing guide that was shown in the tool section also helps with the fleam angle and rake angle. A “Sash”, or hybrid saw usually has a 10 degree  fleam angle and 10 degree rake angle.

Slope

Slope is the angle at which the triangular file rests on the saw plate. See the above animation. For almost all hand saw sharpening, just keep the slope perfectly horizontal (perpendicular to the saw plate).

Shaping the teeth

Hands holding triangular hand saw file while shaping saw teeth during hand saw sharpening

If your hand saw teeth have been shaped already, then reshaping is unnecessary (assuming you want to keep the same shape), and you will only need to lightly joint (step 4 below) and then file for sharpness (step 5 below).

Once you have determined the rake angle and fleam angle, set those angles on your block guide or commercial file guide, and start shaping the teeth. I like to use my Veritas filing guide with the paper guide to give extra consistency. If your saw teeth are already shaped to the angle you prefer, then you can more-or-less just follow the existing shape, and skip this step. Sit or stand near a window, or next to a good lamp.

Make sure the saw teeth are just peeking up above the saw vise, to avoid vibration. Get them level to the vise, and as low as possible. Start filing at the heal of the saw, and work your way to the toe of the saw plate. This way your ugly shaped teeth will be on the least-used end of the hand saw! No matter how long you’ve been sharpening saws, your final strokes are always nicer than your first strokes. You eventually get in a consistent rhythm and muscle memory.

Some people like to run a black marker along the tops of the teeth to measure your progress. If you jointed your teeth before this step, the fresh shiny metal will help you measure your progress. It’s also a good idea to mark each of the three triangular file edges with black marker or white grease pencil. This will ensure that you fully wear out one edge of the file before using the next two edges.

For Rip saws, you can file all the teeth from one side. For cross cut saws, you will need to file every other tooth from different sides. So start from one side and file every other tooth, then file every other tooth from the other side. You will need to adjust your filing guide when you move to the other side of the saw file. File the face of the tooth that is pointing away from you. Use a push stroke, holding onto the file handle with one hand and the file guide with the other hand.

The number of strokes required for the initial shaping can vary, but for newly punched teeth, like in the above video, 2-3 strokes per tooth should shape the tooth most of the way.

After you finish shaping the teeth, site down the length of the saw plate to make sure the teeth are aligned and aren’t filed too low.

Joshua Farnsworth siting down freshly sharpened hand saw teeth in a hand saw sharpening vise

At this point, the teeth should feel pretty sharp, but they will get sharper in the following steps.

Step 4: Lightly Joint the Saw Teeth

Jointing or leveling hand saw teeth with a Veritas hand saw jointer and bastard mill file

If you are sharpening a hand saw with newly punched teeth that are all the same height, then you will just lightly dust the top of the teeth with the jointer and file to barely expose a small shiny, reflective flat spot. Joint from heal to toe, following the flow of the teeth. This will usually be one or two light passes with the file. This shiny “flat” on the top of each tooth will aid in the final sharpening (step 5 below).

Step 5: Sharpening / Final Filing

Sharpening a hand saw with triangular hand saw file

Now that the hand saw teeth have a very small reflective flat surface on top, it’s time to do the final filing to get the saw teeth really sharp. Place a light right above the teeth so that the flats have maximum reflection, and move it around as needed.

Look at the flat reflection, make a judgement, and remove half of the reflection on the first side of teeth, if they’re cross cut teeth. Then as you file from the other side, file the remaining half of the reflection from the other side of each tooth. Some teeth may require a full stroke or two, and some may only require half a stroke to remove half of the reflective flat.

If the teeth grab your finger when you lightly rub across the tops, then the saw is sharp.

Step 6: Test Cut & Adjust

Testing the cut of a newly sharpened antique dovetail saw on a pine board

Using a combination square or try square draw a straight line down a board and make a test cut along the line. If the saw cuts straight and cleanly, then it’s ready to use.

If the saw binds in the cut, then there isn’t enough set, and a bit more set should be added to the teeth. If the saw tracks one way or the other from the straight line, then there is too much set on that wandering side of the teeth. For example, if your saw wanders to the right side of the line, then too much wood is being removed by the teeth on the right side, and you need to slightly reduce the set on the right side of the hand saw.

Stoning Disston hand saw teeth with a diamond stone on a woodworking workbench

Lay the saw plate on a flat surface and lightly run a fine diamond stone or slip stone 1-2 times along the wandering side. Then repeat a test cut to see if the saw cuts straight along the line. Repeat this process until the saw is cutting straight.

Once your saw is cutting straight and not binding in the kerf, then you can do one final thing to get the teeth a little bit sharper. Run the same diamond stone or slip stone very lightly once along both sides of the saw teeth to remove any burr. Then take another test cut to see how finely the saw will cut.

Finally, you can wipe some oil on the saw plate and teeth to prevent rusting and corrosion. This is a good maintenance practice after each use of your hand saw, along with occasionally tightening your saw nuts.

Got any tips to add? Share them in the comment box below!

2017-11-14T12:22:25+00:00

About the Author:

Joshua loves mixing his passion for traditional hand tool woodworking with his ability to teach in a simple manner. He lives on a small farm in Earlysville, Virginia with his wife and four children, and builds furniture in his workshop / woodworking school.

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2 Comments on "How to Sharpen Hand Saws for Woodworking"

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Tanglewood
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Thanks for taking the time to put together this tutorial, saw sharpening has always been a bit of a black art to me, this makes it nice & clear!

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