Chain ID ? (story with pics show why I started filing my own chains)

I got these back from the sharpening shop. Then ended up getting a new bar & an LGX chain & a hand file guide.
Never went back to the semi chisel. I was amazed at the improved cutting performance of the full chisel.
These got sprayed down with oil & bagged up & on the shelf for 5 years.

If you look close, you can see the blue metal on the cutter tips on some of them. To me, they were overheated when sharpened. Some have some ugly burrs on them.
So now you know why I hand file.

20" 72 DL , .050
I think 33RM3-72 , for this one, has the humps in front of the raker to reduce nose kickback.


This one I think is an 33RM - 72


Lots of chain life left if I keep them away for the grinder guys.
How to sharpen & de-burr? I mean, I pull my finger across the cutter tip & it slides by.
Do that to the LGX or RS & the point of the chisel grabs the skin on your finger like a sharp fish hook.

Was thinking I could run them thru a few cuts , that might knock the burrs off. Then
I will hand file.

Another thing, when I sharpen a chain in the shop, I take the bar & chain off, clean up the saw & bar. Grease the bar tip & roller bearing (some one here showed me the trick on that one.) Pour some old
2 cycle gas in a tray, put the chain in there to soak then swish it around to clean it up. Looks pretty clean when I'm done.
Now you guys with grinder, do you clean the chain before sharpening ?
Do the above chains look like they were cleaned? Had to have been smoke coming off them it when the guy was (not gonna say sharpening it) grinding on it.

Any way. that's looking backward farther than needed,
Now I hand file & seem to have some serious sharp chain cutters when I'm done.
I know the LGX was 30% or more faster cutting than these chains (before the above grinding was done)
Now that may improve when I hand sharpen.

It really was impressive the difference there is when a full chisel is sharp. I do mean hang on, this free hand cutting with the face of the saw not against the wood, it pulls the saw face up tight if you aren't ready. Keep the face of the saw tight against the wood & the rounds fall off like your slicing pepperoni with a sharp knife LOL

But; it's part of the RM cutter design, it stays sharp longer & won't need touched up as often.
I know with the full chisel, I'm not spending much time cutting when I get a trailer load.
Saw time is the fast part of getting the load.

So if the 2 above are RM, I'll try to get them sharp & run them when I'm in dirtier wood.
If in clean wood, LGX this year, way to much fun to pull the trigger with a
sharp chisel & see another round falling before the the last one has hit the ground

 

I wipe chain off with a rag or blow off with air if full of junk but I don't clean them. Usually when I did chains this summer it was after cutting wood for 16+ hrs (was putting in 120-130hr weeks) so I wasn't fussy.

A bit of a burr doesn't hurt much. It gets cleared off after a cut or two.

 

Can you clarify this? I don't have direct experience with grinding saw chain, but heating hardened steel to the point of bluing typically makes it softer, not harder.

 

Excuse my ignorance, but can someone show and tell a semi and full chisel pic? I don't know the difference.
Someone owes you a chain or two, although you'll never get 'em.
Found that curious too Jon.

 

Badly blued cutter from a grind, you are correct it will not last as long. A very tiny bit likely never notice any difference I use soft wheels preferably the resinoid bonded type ( typically a brown wheel) when I can get them. They do not burn even with a heavy handed operator for the most part. Down side is they do not last as long as the Oregon or Fireball vitrified types. they generally are 50% less cost than the vitrified though. I had tried the CBN type many years ago I was not impressed, and even less so by the extreme cost which is less now but not by that much. There are some new wheels (brown type)) at one of my suppliers at $5 each. down side is they do not fit Oregon grinders but for me that is not a problem I just make an adapter. They have some others ( brown type) but the wheels are way out of balance. more than it is possible to correct by dressing them. Don't know why, maybe just a bad lot. I do hundreds of chains per year plus my own.

 

Thanks DSS.
So, the difference is the top is larger on full.
The larger cutter is faster?

 

The difference is the square corner vs round corner.

 

Thought heating made it softer if it isn't quenched ?

 

Can't I just file the safety hump down ?

 

Full chisel RS , sharp corner, super fast cutting

Semi chisel, RM, round corner


"Someone owes you a chain or two, although you'll never get 'em."
Yea
Seem to get that on a few cutter no mater who I used (paid) to sharpen them,
no oil or water cooling, that little thin edge & point are gonna get hot with a high speed grinder wheel. IMO

So I figured grinding just inherently overheats the tip of the cutter, so I
decided better for me to learn to file. Found it to be pretty easy.
No over heating, stay sharp longer IMO

 

I'm with you, filing it better, cutters last longer, stay sharp longer, IMO

You'd have to see the burrs on some of these cutters.
Camera not doing them justice for how bad some are.
A burr from a file couldn't be that bad if you tried.

 

Thanks Dave, that shows the difference quite well.
I get it now.
I hand sharpen, but when I started, the "blade" (hehe, I love that) wanted to wander and cut curves.
I've gotten a bit better with more practice, and not nearly as much curve cutting goin' on.
Only had one chain ground, by a friend. He didn't burn any cutters.

 

Cleaned them, put the on the saw & worked them over.

One was to long for the 359 , ? ? Weird

but fit the old 61 OK, left it on the 61. ? ?

Have an RM3, as a dirty wood chain. We'll see how it works.
(ground the pointed tabs in below pic, off of the humped links)


Threw the old LPX away that was on the 61 . Tough to do Might could've sharpened & got one more use out of it.

 

What I noticed when filing, a few of the raker edges were real hard, they
scratched the face of my file.
&
I could tell the file took a few passes inside some of the cutter to feel like it was cutting
the metal evenly & smooth.

Probably a waste of time but a good inside job &
helps improve my hand filing.

 

Okay, that could make sense. I know a little about tool steels, having hardened and tempered a few shop-made tools. Any part of the cutter that's actually blue won't have gotten nearly that hot, because the blue oxides burn off at those cherry-red temperatures you're talking about and leave the surface grey instead. But having blue visible on much of the cutter doesn't mean there wasn't a thin layer of much hotter metal right up against the wheel.

I also know that while tool steels used to need to be quenched suddenly in water or oil (the venerable W2 and O1 steels for example), there are now some designed to be air-quenched. I haven't gotten far enough into the metallurgy to know what manufacturing situations would typically call for air-hardening steels, or why, but it may be that saw chain is more economically made from such.