Identify grind on the chain in this photo

I've never seen an example of a square ground chain. Is this one?

How do you grind at these angles without cutting into the side links? Looks like a machine grind to me.

Yes, that's a square grind. You use an angled file specifically made for that chain and you file it at about a 45* angle to the chain top plate. It's not too difficult. They seem to keep their tips for longer than round grinds do, I suspect there is more meat on them. All my 28" chains are square grinds.

http://www.madsens1.com/bnc_filing_cb.htm

That is a square ground chisel chain. It requires a special grinder, like those from Silvey. They're upwards of $1K.

BTW, this is not a chain for those with little experience sharpening chains themselves. It is difficult to keep the cutters even after a few sharpenings even when you know what you are doing. I usually go 3-4 sharpenings and then just simply have them reground to round because no nearby shop can grind square. On a work site, I bring at least 2 extra chains. Sharpening in the field is more difficult than round due to having to pass the file at such a high angle, making it hard to do with a stump vise. So many will grind from the top. I hate doing that, and find it more difficult to align it that way. So I grind em all before or after.

Thanks guys. I continue to learn but don't think I'll experiment with square grinding after reading the Madsen's article.

7oaks said:

Thanks guys. I continue to learn but don't think I'll experiment with square grinding after reading the Madsen's article.

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You can get a decent used swing-arm style square grinder for around $3-500. I've had the Silvey "Razur-Sharp" and now have the Simington 450b. Once you get used to it, square is as easy to grind as round is. I started hand filing square when I was in high school and round filed prior to that.

Someone who is really good with a file though can make a square chain that will easily outcut a ground chain.

The advantages are:

They last a LONG while in softwoods, so PNW'rs love em. They have a very strong chisel tip that wont ever go away unless it hits something hard. Once slightly dulled, you can file back the rakers and get more out of them if need be in the field. In pine it isn't bad, but in hardwoods, the chatter can be an issue. And, perhaps most importantly, nothing short of a full race chain will out cut a square grind. Nothing.

Here are mine after 2 sharpenings and maybe 2 quick touch ups. You can already see them losing some of their freshness, and the rakers need to be taken back now. I was experimenting to see how long I could cut without lowering them(which isn't very long at all). In soft wood, I would file the rakers on a square nearly every time you have to do any serious sharpening:





And this is what it does buried in big leaf Maple one a 28" bar with a stock, MM'd 372XP. That is Oregon CJ - skip tooth square grind. Notice how I lose very little revs even while buried.

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/njuHgek8R6Y" frameborder="0" allowfullscreen></iframe>

Jacob J. said:

You can get a decent used swing-arm style square grinder for around $3-500. I've had the Silvey "Razur-Sharp" and now have the Simington 450b. Once you get used to it, square is as easy to grind as round is. I started hand filing square when I was in high school and round filed prior to that.

Someone who is really good with a file though can make a square chain that will easily outcut a ground chain.

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Sure wish there was someone close to me with a sq grinder. I don't have time to practice what I already know so I don't need to learn anything more. LOL

wyk said:

The advantages are:

They last a LONG while in softwoods, so PNW'rs love em. They have a very strong chisel tip that wont ever go away unless it hits something hard. Once slightly dulled, you can file back the rakers and get more out of them if need be in the field. In pine it isn't bad, but in hardwoods, the chatter can be an issue. And, perhaps most importantly, nothing short of a full race chain will out cut a square grind. Nothing.

Here are mine after 2 sharpenings and maybe 2 quick touch ups. You can already see them losing some of their freshness, and the rakers need to be taken back now. I was experimenting to see how long I could cut without lowering them(which isn't very long at all). In soft wood, I would file the rakers on a square nearly every time you have to do any serious sharpening:


And this is what it does buried in big leaf Maple one a 28" bar with a stock, MM'd 372XP. That is Oregon CJ - skip tooth square grind. Notice how I lose very little revs even while buried.

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Thanks for the info and photos and video. That is one screaming combination.

I really don't think square is any harder to file than round -- you just have to get the hang of it. Agreed that you want it machine ground to keep the angles straight after a few hand-filings, though the same can be said of a round grind.

Here's a picture of a tooth I ground on a swing arm.

madhatte said:

I really don't think square is any harder to file than round -- you just have to get the hang of it. Agreed that you want it machine ground to keep the angles straight after a few hand-filings, though the same can be said of a round grind.

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It's not any harder once you know where the angles need to be and for me- square is easier to file out in the field than round. I can touch up a semi-skip chain on a 32" bar that's wood dull in about 3 minutes on a square filing.

Some nice upclose pics!

One can tell from this pic that the chain grinder is a quality one. The chain stop isn't a thin stamped metal. Quality all around!

I love a good hand square filed chain. Ive been square filing for about a year now. I hand file a chain until its gone. It takes a lot of practice. I am able to switch hands effectively while filing, which helps. I also run my chain very aggressive, filing my rakers 2-3 swipes lower than reccomended. Gonna try to learn to goofy file now....

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Jacob J. said:

It's not any harder once you know where the angles need to be and for me- square is easier to file out in the field than round. I can touch up a semi-skip chain on a 32" bar that's wood dull in about 3 minutes on a square filing.

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Zackly. It's one, maybe two licks per cutter with a sharp file. Pushing down on the bar means it's easier to keep the saw stable, too. I like those 4-sided files best because they last so long, and there's no pointy end to stab you when it's in your pocket.

First time i have seen square ground so i learned something too. Ive heard of it but never seen it.

Also Carl, that camera takes a great pic!! I gotta get one of those. I looked at my lenses and the camera they go on is a minolta Maxxim 5000i.........lenses fit ne thing else digital??

ryans4022 said:

lenses fit ne thing else digital??

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Yes! All of the current Sony DSLR's are re-badged Minoltas. Lookin' to get one myself as I have a lot of old Minolta gear.

madhatte said:

Yes! All of the current Sony DSLR's are re-badged Minoltas. Lookin' to get one myself as I have a lot of old Minolta gear.

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There you go Ryan! AS never ceases to amaze me in its depth of knowledge. Ask and someone on here has the answer.

ive ran some stihl square and oregon square and havent felt any seat of the pants performance over round. but i cut mainly red fir wich might be quite abit softer then you guys cutting hardwoods.

I've never run stihl square only oregon. I've got one stihl chain on the 20" b/c and it's RSK instead of RSC. The only difference I know of is the raker is thinner.