Friedrich Dick 3-Square Needle & Saw Taper Files

Three-Square Taper Saw File

140mm needle (16-17 ppi) $17.95 USD 160mm needle (15 ppi) $18.95 USD 200mm needle (14 ppi) $19.95 USD

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Three-Square Taper Saw File

4-inch xx-slim (13 ppi) $7.95 USD 5-inch xx-slim (12 ppi) $8.95 USD 6-inch xx-slim (10-11 ppi) $8.95 USD 6-inch x-slim (9 ppi) $8.95 USD

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Three-Square Taper Saw File

6-inch x-slim (9 ppi) $8.95 USD 8-inch x-slim (7-8 ppi) $9.95 USD 8-inch slim (6 ppi) $10.95 USD

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Three-Square Taper Saw File

8-inch x-slim (7 - 8 ppi) $9.95 USD 8-inch slim (5 1/2 - 6 ppi) $10.95 USD 8-inch regular (4 - 5 ppi) $11.95 USD

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Jointing & Deburring Files

10-inch Mill File (Jointing $14.95 USD 8-inch Chainsaw File $6.95 USD

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Skrooz-On File Handles

for 4 xx-slim - 5 xx-slim $5.95 USD for 6 xx-slim & Chainsaw $6.95 USD for 6 x-slim $6.95 USD for 8 x-slim $6.95 USD for 8 slim $7.95 USD for 8 reg & 10-inch mill $7.95 USD

Ever sneak an eBay package into your workshop late at night containing a box of saw sharpening taper files, glad you were able to snap them up new? You unwrap them fresh out of the vapor corrosion inhibitor paper where they have been carefully interleave-wrapped one by one, and lay them out on your workbench, marveling at their crisp teeth and uniform taper. You then gird your loins, resolved to sharpen your own saw for the first time, attach a handle to one of them, and thus armed joint a row of flats on your 26” Disston No. 12 Handsaw with a fresh mill file. Aligning your light and donning safety goggles, you carefully take your first stroke into the row of gullets you intend to bring back into perfect symmetry.

And another stroke, followed by another. You squint through your goggles impatiently, wondering if you're actually abrading metal or just going through the motions. It seems you're having to really make that file bite into your toothline to get it going. And then halfway down the toothline you realize the bitter truth: the name on the box may denote a time-honored company, but the reality is you’ve worn out the file before you could even finish the first pass. Holding your file up to the light, you see that the corner edge looks shiny and slick, and now you’re mad. Really mad! Spent $80 bucks for a box of files that are only good for the recycling bin. Disgusted, you resolve to ship your saw to one of the saw docs servicing the hand tool industry for a restoration job you really wanted to do on your own.

Welcome to my world. It didn’t take long to figure out that the only truly decent files around made by Simonds, Johnson, Nicholson and Oberg are the ones you see on eBay with the raggedy, tattered boxes on the outside. In other words—you want the files made before companies began outsourcing the work offshore with inadequate quality control in recent years.

We’ve been sharpening saws at Bad Axe for 12 years now, and new old stock files were our lifeblood for virtually our entire existence. The rule of thumb was, ‘the rattier the box, the better the file.’  So for our first decade we snapped up every new old stock file we encountered, and grimaced as supplies dwindled on eBay and flea markets, and prices escalated.

But availability is always finite when something is no longer made or manufactured to the quality desired. First to go were the 4” xx-slim files, the default dovetail saw file of choice. You just don’t see new old stock for this category anymore on eBay, period. Then the 5 xx-slim file, great for carcase saw work, dried up. You can still find 6 xx-slim for your tenon and miter saws, but even that size is noticeably dwindling.

The good news is that there are reputable European file companies still around from whom one may source quality files: Friederich Dick from Germany (distributed in the US by Bad Axe and in Europe by Dictum), Corradi (distributed in the US by Tools for Working Wood), Vallorbe from Switzerland (distributed in North America by Lee Valley Tools), and Bahco—a Swedish firm making files in Portugal also distributed in North America by Lee Valley Tools.

What many people may not realize is the impact having a needle file in your arsenal can have on your finer-toothed saws in the 14-pitch and finer ppi counts. Friederich Dick, Corradi and Vallorbe make them in three-square format. Needle files are nearly three times as expensive as a regular saw file, but they’ll give you a deeper gullet and longer cutting edge, and last twice as long for dovetail and carcase saw work. At Bad Axe, we can use a needle file for at least three separate sharpenings before the file wears out.

Which brings us now to the file size table you noticed at the top of this page, that identifies a file type and size per ppi. Traditional saw filers have long held to the convention that 4 xx-slim is ideal for filing 14 ppi and finer, due to its diminutive cross-section for a diminutive tooth size. And it still applies. What follows is how Bad Axe integrates needle files and slims down certain standard saw taper file sizes to get the kind of result that works best for how Bad Axe sharpens all saws, including the saws we make and vintage saws our customers still send in to us for restoration.

A word first about sawtooth terminology and saw sharpening taper file sizing conventions: Generally speaking, you want to present a little more than twice the face of a file in comparison to the size of a given tooth. This lets you use the file a minimum of three times for three saw filings without wearing the file out by overlapping a given sharpening into an area along the face already used.

That said, there exists nonetheless a degree of flexibility as long as you don’t reduce a tooth into little nubbins by using too large of a file’s cross section. Let’s address terminology first:

Terminology:

• PPI vs. TPI: Points per inch (ppi) is measured by how many points are bracketed by inch-long increments of a ruler, beginning with the first point at the increment, and concluding with the last point of the next increment. Teeth per inch (tpi), is counted one less point, with the count beginning at the second point as ‘one,’ then moving forward till the last point hits the next increment. For instance, an 8 ppi handsaw is considered 7 tpi. Sawmakers prefer to use the ppi method when denoting pitch.
• Pitch: aka for points per inch, or ppi.
• Cross-section: The cross section of a file is a 60-degree equilateral triangle, just like a saw tooth.
• Taper: A saw sharpening file is referred to as a taper file; that is, it tapers from the tip to the tang, broadening in cross section along the way. This enables the sharpener to hit two adjacent tooth edges per gullet.

Sizing Conventions:

• All saw taper files are designated by length and cross-section. Length is generally graduated in inch-long increments, starting at 4” files, then graduating to 5”, 6”, 7” and 8“. Cross section sizing begins at double-extra slim—xx-slim for short—then goes to x-slim (broader in cross-section), slim (broader still), and regular for the coarsest teeth.
• For example, one of the smallest files you can use for dovetail and carcase work is a 4” double-extra slim, or 4” xx-slim for short. This means it’s a diminutive file for 13-15 ppi toothline (although we prefer o use needle files for that purpose), and has a small cross-section.
• Personal Preference: Though we could use a 4 -slim with a correspondingly broader cross-section for 12 ppi, we prefer to use 5” xx-slim, since the extra length gives us the broader cross-section we seek. We prefer still using the xx-slim cross-section for a 6” file, which hits the 10-11 ppi range quite effectively, followed by a 6” x-slim for 9 ppi and so on.

Recommended file sizes by type and utility: With that in mind, we use needle files for all—ALL—of our dovetail and carcase saw work, ranging from 14 ppi (think Bayonet up to the 17 ppi configuration we use on our Half-Blind DT saw and Luthier saw. Three different sizes of needle file apply: 140mm for our 17 ppi saws, 160mm for our 15-16 ppi saws (10” and 12” Stiletto DT saws), and 200mm for our 14 ppi Hybrid DT/Small Tenon Saw and Bayonet Precision Carcase Saws. Alternatively, we could use a 4” xx-slim file for all of these saws, and it will work, but we find that the needle file simply gives us a longer cutting edge where the thin plates of these saws truly excel for furniture-grade cuts in quality hardwoods.

We then move into the more conventional saw taper files for our coarser-toothed carcase saws and tenon saws, such as what you see with our 14”, 16” and 18” tenon saws and our 20” miter saw. 4” xx-slim is not too fine to handle 13 ppi—again giving one a deeper gullet with longer cutting edge. 5 xx-slim works great for 12 ppi, where we file the majority of our tenon saws, our 14” sash, 16” tenon and 20” miter saws. 6 xx-slim works fine for larger 18” tenon saws and vintage miter saws & panel saws frequently filed at 10 – 11 ppi.

As we progress into the world of panel saws, a 6” x-slim or 7” xx-slim works out perfectly for pitches at 9 ppi. Graduating to 8” x-slim fines a good fit for handsaws filed 8 ppi, and 8” slim for 7 ppi kerfing planes and rip filings at that pitch. 8” slim completes the hand and panel saw realm for 5 ½ ppi and 6 ppi. Our largest file at 8” regular addresses 4 and 5 ppi, pitches best reserved for coarse ripping handsaws and frame saws.

Exceptions to the ‘rules:’ Notice again that we at Bad Axe prefer to use a 200mm needle file for 14 ppi filings, a 160mm file for 15 ppi filings, and 140mm for 17 ppi and finer filings. That is our preference. One can just as easily use a 5” xx-slim file for 14 ppi and 4” xx-slim for 15 ppi and finer. Your teeth will be a little nubbier, but perfectly serviceable. We simply prefer using the needle file approach for our finer pitches, because it gives us a deeper gullet and longer cutting edge for our dovetail and carcase saws with correspondingly thinner plates. That said, needle files are significantly more expensive than traditional saw taper files, and so that is why 4 xx-slim and 5 xx-slim remain a viable and less expensive solution for dovetail and carcase saws.

Likewise, one can ‘size-up’ or ‘size-down’ for reasonable results. For instance, let’s say you have a 10 ppi tenon saw. While a 6” xx-slim is a tad small in cross-section for this pitch, you may find yourself (living in a shotgun shack) wanting to size down to deepen the gullets of a vintage saw where the last sawfiler has clumsily filed a big-tooth/little-tooth pattern, and the gullets are very asymmetrical; you now seek to deepen the gullets as much as possible. Even though the ‘correct’ file size for this pitch is 6” x-slim, the 6” xx-slim is a better file to use given your asymmetrical gullets dilemma. The tradeoff is you’ll wear it out faster than the 6” x-slim.

Conversely, you may have a scenario where your toothline is completely overset, a common scenario when picking up saws off eBay. Say you have a 6 ppi handsaw where a 8” slim file will optimize the toothline, but because the teeth are overset, you want to hog off more metal so you can reduce that set. In this scenario, I’d use a 8” regular file to knock the teeth down, then re-file it with an 8” slim file, re-set the teeth appropriately, then brush it up once more with the 8” slim file. See how that works?

These deliberate file choice considerations stepping up or stepping down have a direct correlation to how much set you want to keep or reduce given the scenario with the saw you have purchased or inherited.

Jointing & Deburring: We offer Friedrich Dick's 10" mill file, and excellent choice for jointing sharpening flats along the toothline before sharpening the saw. Think of the jointing file as a long jointing plane—the long plane of the file establishes one's visual queue for sharpening by creating a fla on the tooth. Once you've sharpened off the flat (and no more!), then your tooth will be in jointing alignment with all other teeth, such that all teeth cut in unison. Friedrich Dick's chainsaw file is a useful file for deburring a sharp edge along the non-toothline perimeter of one's saw by drawing it backwards against the burr. This is common when one shears metal when shortening a saw due to a severe kink at the toe, or for widening an offset fastener through-hole in the plate when transplanting a handle.

Safety Considerations:
Always remember that sawfiling kicks up a lot of dust, and we’re not talking about your garden-variety wood dust, which can send you into sneezing fits. No, we’re talking metal dust here, and that’s some nasty stuff. Think about it: metal dust is actually metal shrapnel under the magnifying glass, and though it may seem innocuous while floating in the air, it’s not. Just consider what it can do deep in the alveoli of your lungs if you’re wearing a dust mask, or how it would interact with your corneas when you wake up in the morning unshowered after a sawfiling session and you’re knuckling the sleep out of your eyes.

So be safe. Wear a dust mask and eye protection when you’re sawfiling. I like keeping a cordless vacuum handy to suck up all the metal dust particulate before, during and after a sawfiling session. Metal filing dust is dangerous stuff, and you’ll definitely want to keep it out or your eyes, nose and mouth.

Safety when mounting handles: Saw files are brittle and pointy. Don’t get in a rush and mindlessly push a handle on to a file’s tang by leaning into it—you might well stab your hand, or your hip, depending on your body English!

You are far better served safety-wise by securing your file handle up in a vise, then tapping the handle onto the tang with a light mallet.

If you’re screwing one of our Skrooz-On handles onto the tang of a file, you’re still best served by securing it upside down in a vise, so you can bear down on the tang with the handle without putting yourself in jeopardy.

Think about it: if you’re bracing the tip of the file against an immovable object and pushing the handle into the tang, what would happen if you get too gung-ho and the file snaps? Where does that sharp metal go? Into your hand, right?

Or, depending on how you’re leaning your body into the tang, somewhere you don’t want that file to be. Exercise good sense here too.

A final note about handling a file: sometimes a handle has just a smidge too large of a bore to securely fasten the tang of your file. A couple of wraps with masking tape around the tang will make up the difference and get your handle on securely.