Square filing chains

45° down
45° back
45° roll (in the hand)

 

Thanks WW -

Those pictures are EXACTLY what I needed. I went out to play yesterday to see how the chain worked and grenaded my recoil on my 572 on the first pull. Had my 450 rancher in the wings so I didn't bother pulling it apart to see what's up. I suspect the pawls broke. <sigh> Maybe next week if I can get parts.

So when you file square, you don't line up the file with the angle line that is scribed on the cutter?

Thanks again for the help guys!!

 

You likely need a new recoil pulley on your 572, it’s quite common. If you have tightened down the recoil without jiggling the pulley posts into place, it may have bent the flywheel pawls down. If that’s the case, they will grab further out on the pulley posts and destroy your new pulley in short order.

Don’t pay any attention to the top line, it means the least. Get your corner lined up. File down on an angle steep enough that your chain will stay sharp for a while, roll the file in your hand so that you have enough forward lean to make the chain pull itself into the wood with rakers at .025, and the top plate angle ends up wherever it ends up. Usually about 17–20°.

 

You can make that top plate angle what ever you want it to be but yes, for regular firewood chain I'm at the same angle as the factory witness line. When I sharpen milling chain, I shoot for 10-15 degrees on that angle, for better durability.


To be honest, not sure if I would have just tried square filing on my own. I had a "pro" offer to teach me how (the guy that started this thread). He was traveling for work and happened to be close by. Having someone there in person was all the difference. I was able to get into the sweet spot fairly quick. After cutting w/ square and feeling the difference, I never went back to round.

 

Inbred Jed (RIP) has a good video on square filing also.

 

Hey Guys -

Is it possible to square file .325 pitch chain, or would that not be a good idea? To much for a rancher 450?

 

.325 can be square filed no problem. Depending on what brand file you use it can be a tight fit. Watch you don't get into the tie strap too much. And definitely not too much for any saw. Just adjust your raker/depth gauges appropriately.


.325 Stihl chain

 

I square file the .325 on my MS250 by hand all the time and it's a chip tossing machine. I use it a lot and I bore cut Swedish candles with it all the time. Jason has it down in his pic above... I get into the straps a little with the double bevel, but I also clean the gullet out with a 5/32" (4mm) round file first to make the square filing easier. That keeps the double bevel file from having to work down the full side plate and getting into the gullet with the bottom bevel.

A sharp square filed chain with the rakers set properly for your saw will make any saw perform better and cut faster. And when you're getting the corner of the file to meet the tip of the tooth like Jason's top picture, the support it gives that tip in two dimensions makes it stay sharp longer as well.

My pictures aren't as good, but I'm trying to show that the gullet is cleaned out enough that the double bevel file only works the side plate down part ways and doesn't get into the gullet.

What you don't see in this picture is the tip of the tooth that is in my finger!!! And the little trickle of red stuff that came out of that hole!!! LOL

 

Excellent - Gonna have to try a square filed chain on my rancher. I was so impressed with it on my 572, if I can make it work on a lighter saw, I can save the 572 for the big stuff and use the rancher for the smaller stuff.

 

Crappy pictures but my filing is improving. For a while I was getting some back lean, which I corrected. I found a 5/32” round file is perfect for clearing out the gullet and blending everything afterwards.

 

Did you take that pic with a potato?

-2 pts

 

Yukon Gold to be exact. I have to walk away from this for a bit. One side of the chain came out mint, while the other is a mess. Top plate angle is all wonky. I’ll try again later and hopefully I don’t run out of chain to file before getting it right

 

The solution for me: go from the outside-in on one side, and inside-out on the other side. Weird but it works.

 

Higher resolution potato:

 

That looks rather good IMO.

 

That one looks really nice, Eric

 

Incremental improvement. I have a little forward lean to the side plate now. The angle of the top plates are a little shallow, like milling angles, but I’ll give it a go. The main thing is from one side of the chain to the other the top plate angles are consistent. Over time I’m sure I can get a little better at this. This 18” chain is kind of a beater chain for my Husqvarna. It started life as a rusty Oregon Vanguard that I thinned the rakers on, then ground the rivets down a few thousandths. Looking forward to seeing what it does in some wood soon.

 

Looks good. I'll bet it cuts just fine. I'm still a square file noob tho.


My first couple loops and usual first couple teeth now have top plate angles like that. Then i realized i really gotta point that file back more than i imagined i needed to match the wear mark.

 

Do you square file your chains in a vise or on the saw with the bar pinched in a vise? I did this one with the chain pinched to one side of the vise but I was fighting to get the angles I was after.

 

On the saw. I don't have a fancy ol vice.