Good saw files are hard to come by.
Bad Axe now offers the best.

Friedrich Dick 3-Square Needle & Saw Taper Files

Dovetail & Carcase Saw Files


Carcase and Tenon Saw Files


Tenon, Kerfing Plane & Panel Saw Files


Panel, Hand & Frame Saw Files


Jointing & Deburring Files
 

Lutz Comfort-Grip & Skrooz-On File Handles






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 one by one, and lay them out on your workbench, marveling at their crisp teeth and uniform taper, attach a handle to one, 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 indicate 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 pissed. Spent $60 bucks for a box of files that are only good for the recycling bin. Disgusted, you resolve to send your saw in to Bad Axe 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 farming the work out to to China in recent years. Those beat-up old boxes may look ugly on the outside, but there’s actually gold on the inside--because those new old stock files made in the US before NAFTA are hardened and tempered significantly better than the trash made in China today.

We’ve been sharpening saws at Bad Axe for 10 years now, and new old stock files are our lifeblood. The rule of thumb is, ‘the rattier the box, the better the file.’ It took only two experiences with the shiny new stuff to realize I needed to stop peeing on the electric fence, as Will Rogers once observed nearly a century ago. So for the past decade we snapped up every new old stock file we encountered, and grimaced as supplies dwindled and prices escalated.

But availability is always finite when something is no longer made, or made to the quality desired. First to go was 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.

I remember how over the past three years we aggressively pursued other makers who still made files in Europe, because all the US makers were no good any more, very sad to say. Grobet in Switzerland seemed promising at first, then their files went to hell. Yup—they began farming them out to China. Bahco is a Swedish company—the files are actually made in Portugal—and though quite serviceable, they still aren’t as good as new old stock from Nicholson or Simonds. We began purchasing needle files made by Vallorbe in Switzerland, and for six months, we were in heaven.

Needle files are expensive as hell, but they’ll give you a deeper gullet and longer cutting edge, and seemed to last longer for dovetail and carcase saw woek. But then came along a box of 10 no-good files—the hardness & temper disease had hit! Undeterred, we went through three more boxes of 10 and found no joy there either. We had been buying these files from a US distributor, and because it took us more than 30 days to realize the magnitude of our poor investment we had surpassed our authorization for a refund.

Our German Solution: We finally struck gold when we found Friederich Dick, a German file and knife-making company in business since the late 1700’s who offers old-world quality files at a premium but ultimately doable price. Determined to become a US distributor I brushed up on my (very) rudimentary German, contacted FD and managed to establish rapport without getting (figuratively) slapped in the face. FD sent us a batch of files representing the gamut of ppi specs for every saw we make.

We were blown away at their bite and longevity.

We also contacted the Maine Company who makes Skrooz-On file handles (always loved those handles—they literally cut into a file’s tang like a die for a secure attachment) and defined what works best for Bad Axe.

The upshot of all this? Bad Axe is now in the business of consuming and re-selling quality files and file handles! Our litmus test? Our own day-to-day consumption of files in manufacturing. After all, we wouldn’t sell something we don’t use on a daily basis ourselves.

No longer must I hang my head in shame at our saw sharpening seminars and tell our students they have to search out new old stock on eBay to find decent files with which to sharpen their saws. No more must we predicate the survival of our company on finding new old stock in the size we need.

Which brings us now to the file size table you noticed at the top of this page, which 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 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 crap, and you’ll definitely want to keep it out or your eyes, nose and mouth.

One more thing: if you’re pushing your files into your handles, such as with our comfort-grip handles made by Lutz, or with a vintage Disston handle, or any other push-in type file handle, your 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 he file snaps? Where does that sharp metal go? Into your hand, right? Of, 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.