Two files marked for the same job can behave nothing alike. The mixup is usually length versus cut grade, and they are not the same spec. Buy on length alone and the file may not match your saw’s teeth per inch at all.
Saw sharpening files get labeled two ways. The first is length, like four inch or six inch. The second is cut grade, like extra slim or double extra slim.
The length is just how long the triangular file is. The cut grade is how fine the teeth are, and how narrow the file body is. That narrow body is what has to fit between two saw teeth.
Confuse length and cut grade and the results are frustrating. You either round over fine teeth, or spend ten strokes per tooth on a coarse rip saw. This guide breaks down saw sharpening files by grade, and matches them to tooth counts.
It also lays out where Nicholson, Bahco, Pferd, and Grobet actually differ in owner reports.
What actually determines the right saw sharpening files for your saw
Two variables decide the match, not one. The first is cut grade, running coarse to fine: regular, slim, extra slim, or double extra slim. The second is length.
A six inch file and a four inch file in the same cut grade are not the same width. The narrower grades are also physically thinner, not just finer toothed.
A finer cut grade means smaller teeth, packed closer together. It also means a narrower file body. That narrow body has to ride in the gullet between two teeth without rounding the points.
Our matching a file to whatever else needs sharpening in the shop piece covers the same idea. It applies to files used on other tools too.
The table below lines up common cut grades against the tooth counts they are built for. Treat the ranges as a starting point, not gospel, because sources do not fully agree with each other.
| Cut grade | Typical length | Teeth per inch | Best for |
|---|---|---|---|
| Regular | 8 to 10 inches | 3 to 5 TPI | Big rip saws, framing saws |
| Slim | 6 to 7 inches | 5 to 8 TPI | General crosscut hand saws |
| Extra slim | 5 to 6 inches | 8 to 12 TPI | Fine crosscut, dovetail saws |
| Double extra slim | 4 to 5 inches | 10 to 15 TPI | Backsaws, gents saws |
The double extra slim grade is where sources disagree the most. One retailer rates a six inch file at nine to ten TPI. Another lists eight to eleven TPI for the same size.
A third source puts it closer to ten or eleven TPI. None of them are wrong exactly. File makers simply have not published one shared standard.
Filing is only one piece of getting a saw cutting well again. Our how the whole saw sharpening job fits together guide covers the rest, including set and jointing. A file that matches your TPI will not fix a saw with the wrong set.
Quality across makers: Nicholson, Bahco, Pferd, and Grobet
Brand loyalty runs strong in this corner of the shop. Recent owner reports on saw sharpening files are messier than the reputations suggest. Nicholson is the name most people default to first.
The recurring complaint is inconsistent cutting since production shifted to Mexico. Some owners report a new file dulling within a single saw. Others report no issue at all.
Woodworking instructor Paul Sellers has been one of the more vocal critics. He reports a new Nicholson file that stopped cutting after about eight inches of filing on one saw. That is a steep drop for a brand built on consistency.
He rates Bahco files as the most durable he has used. He describes results well past thirty sharpenings from a single file. He also lists Grobet as a strong, fairly priced option in the US and Canada.
Pferd shows up less often in saw specific talk. It appears more in chainsaw file recommendations, where owner reports skew positive. Country of manufacture seems to matter more right now than the name on the handle.
None of this means one brand is safe to buy blind. It also does not mean another brand is safe to avoid outright. Treat one bad batch as a batch problem, not proof the whole line has gone downhill.
Feather edge files: a narrower use case
Feather edge files are a flatter, thinner taper file. Some sharpeners use them for finishing very fine rip teeth. Coverage of this file style is thin, and no manufacturer spec page for it turned up in research.
Treat a feather edge file as a specialty option, not a first purchase. Wait until you already know your saw needs one.
How this compares to sharpening other blades
Saw sharpening files use a triangular cross section. That shape is built for the included angle of a saw tooth. Knife edges and garden tool blades need a flat or curved face instead.
Our how sharpening tools stack up across every blade type page lays out where each tool fits. Circular saw blades and band saw blades get sharpened differently again, usually with a grinder rather than a hand file.
Our the separate process for power saw blades guide covers that side of the shop. That is worth a look if a power saw is what actually brought you here.
Mistakes to skip
The most common mistake is buying one file and expecting it to cover every saw in the shop. A single grade rarely spans a rip saw and a fine backsaw well. Plan on owning more than one grade.
Retailers often shelve these files as a generic taper saw file, with the grade printed small on the tang. Check that stamp before you buy, not after.
Another mistake is filing with a worn file past its useful life. A file that skates instead of cutting will burnish the teeth. Retire a file once it stops biting on the push stroke.
Skip stamped or cast tooth files sold online as saw files. The geometry is wrong for hand filing. Owner reports on them are consistently poor.
Our options built specifically for saw sharpening page covers powered alternatives. That route makes sense if hand filing is not the direction you want to go.
The bottom line: Match cut grade and length to your saw’s TPI, not just one. Expect to own two or three grades if you maintain more than one saw. Buy based on recent owner reports for the specific batch, since manufacturing quality has moved around more than brand names suggest.
What size saw sharpening files do I need for a 10 TPI saw?
A 10 TPI saw typically calls for an extra slim file in the five to six inch length. Check the saw’s actual tooth count with a ruler first. Stamped TPI numbers on old saws can be misleading.
Can I use one file size for every saw in the shop?
Not well. One grade might cover a narrow range of TPI, but a rip saw and a fine backsaw need different cut grades entirely. Plan on two or three files if you maintain more than one saw type.
Are Nicholson saw files still good?
Owner reports are mixed since production shifted to Mexico. Some batches perform fine and others dull fast. The recurring complaint points to inconsistency, not a total decline.
What is a feather edge file used for?
It is a narrower specialty taper file some sharpeners use for finishing very fine rip teeth. It is not a common first purchase. Most home sharpeners never need one.
How long should a saw sharpening file last?
That depends on the steel being filed and how many teeth get touched per session. Some owner reports describe thirty or more sharpenings from one file. Others report a file dulling within one saw, usually a sign of a bad batch.
Do I need a file handle?
A file handle is not required, but it protects your hand. It also gives better control on the push stroke. Our everything else in our sharpening lineup page covers other small accessories worth having around.
Sources
- Rose Hulman Institute of Technology: Taper Files Explained, faculty reference on saw file grades and sizing. https://www.rose-hulman.edu/~wollowsk/wood/taperfiles.pdf