In my first chainsaw post I discussed saw sizes and components. No component is more important than the chain that does the work. And no aspect of a chainsaw is as controversial and creates more arguments among users than the type of chain you should use.
Chainsaw Chain Basics
A chainsaw chain consists of drive links, cutters, tie straps, guard links, and the rivets that hold them all together. Oregon has a great picture showing these parts at http://www.theoregonshop.com/userimages/ChainParts.jpg.
All the parts are also shown in the photo at left. The parts don’t matter to most users since most people don’t assemble their own chain. But understanding them helps when it comes to understanding chain sizes.
Saw chain size is defined by three parameters:
- Pitch, or the length of the links (distance between rivets).
- Gauge, or the thickness of the drive links.
- Length, or the number of drive links.
There’s a picture of this on the page at http://www.stihllibrary.com/pdfs/SawChainSelection.pdf from Stihl. Remember that chains are sized according to the bar they run on, not necessarily by the size of the powerhead, although larger powerheads tend to run larger bars, so there is some relation. In general, smaller saws with bars under 16″ run chain as small as 1/4″ pitch. Medium size saws with bars between 16″ and 20″ run .325″ or 3/8″ pitch chains. Larger saws with bars longer than 20″ may run .404″ pitch chain.
For example, my 18″ Rollomatic E bar on my Stihl MS 290 runs .325″ pitch chain, .063″ gauge, with 74 drive links. here is the information plate from the bar. I also have an older Rollomatic E bar that is the same 18″ length which I used to run on my old 032AV, which is actually a 3/8″ pitch, .050″ gauge, and takes a chain with 66 drive links.
Although it’s important to buy the correct size chain for your bar, most people don’t pay much attention to other parameters. Some people like to argue the merits of .325″ pitch chain vs. 3/8″ pitch, but most people don’t care. What people do care and argue about is the type of cutters on the chain.
Chain Cutter Types
The number one argument among chainsaw people is whether full-chisel or semi-chisel chain is better. What’s the difference? It has to do with how much of the cutter is sharpened and the geometry of the cutter on the chain itself. A simple explanation is that if you look at a full chisel chain end-on, the cutter looks like the number seven “7″. A semi-chisel chain looks like a question mark, “?”. There is also a difference in how much of a point is filed into the front profile of the cutter, with full chisel chain having a sharp point, while semi chisel is flatter.
Wikipedia says this:
Full chisel chain has a square cornered tooth, splitting wood fibers easily in the cut for fast, efficient cutting in clean softwood. Semi-chisel chain has a rounded working corner formed by a radius between the top and side plates. While slower than full chisel in softwood, it retains an acceptable cutting sharpness longer, making it the preferred choice for dirtier wood, hard or dry wood, frozen wood or stump work, all of which would rapidly degrade full chisel chain.
Bailey’s, an excellent source for chainsaw parts and chain for all brands posts this picture describing chain types. (Note that what I call full chisel they call round chisel – same stuff.) For homeowners and non-professionals the choice is really between full or semi chisel. The other stuff, especially square chisel, is used only by pros and really dedicated amateurs.
One of the best sites for chainsaw information on the Internet is Arboristsite.com. And they relish the debate over full or semi-chisel chain.
Reading through all those threads the consensus opinion is that full-chisel chain cuts faster when sharp, but loses its edge quickly, especially in “dirty” wood. Semi-chisel chain cuts a little slower, but holds its edge much better. So which is better? For homeowners and occasional users it really doesn’t matter. You see, most of the argument happens between guys that cut wood for a living. Or at least serious amateurs who spend hours in the field on any given day. So to them, the speed that a chain cuts makes a difference in how much money they make. For me it doesn’t. I simply don’t cut that much wood.
And the definition of “dirty” certainly isn’t standard. Is dirty wood a log that has been skidded on the ground through a swamp and is caked in mud? Some people in those threads argue that trees which grow on the side of dirt roads count as dirty because of the microscopic sand embedded in the bark. The point is – the posters are technically right. In my experience full-chisel chain dulls quicker than semi-chisel. But since I don’t cut ten trees a day it doesn’t matter to me if it dulls and slows down much. I’ll spend a few more minutes with the file between tanks of gas if I have to – it gives my back a rest! So read the posts and make up your own mind. But realize that for occasional use, it probably won’t make much of a difference.
What do I Run?
Mostly full-chisel chain. Currently I have four loops of Stihl RSC (Rapid Super Comfort) full-chisel hanging in my tool shed. I also have two loops of Stihl RMC (Rapid Micro Comfort) semi-chisel hanging there. Most of the time I run the RSC full-chisel. Even in hardwood (I cut mostly oak and maple here in Massachusetts, with some white pine thrown in) and even in cold weather when the wood may be frozen. But I am very careful, and after years of experience am quite adept, at keeping the bar out of the dirt. Because it doesn’t matter whether you’re cutting hardwood or softwood and whether the wood is dirty. Nothing will kill your chain faster, whether full or semi-chisel, then running your bar into the dirt and rocks under a log!
Note that I mentioned using a file. Yes – you must sharpen your saw chain. No, taking it back to the hardware store doesn’t count. Sure, all chains need to be reground periodically, but a single chain is only going to last a couple of hours, even in clean wood, before it needs to be touched up. In this area the forum consensus is also right: semi-chisel chain will go longer between filings. If you have no intention of learning how to file a chain, you need to assume that you will go through three to six chains in a full day of work and plan on buying that many. So if you only want to to take them back to the store for sharpening, buy six or eight or ten loops to get you through a full weekend’s work.
So my recommendation comes down to this:
- If you are careful with your cutting and keep your bar out of the dirt, full-chisel will work for most applications, if you’re willing to occasionally file and maintain the chain.
- If you are new to using a saw and don’t want to file your own chains, run semi-chisel.
Regular or Reduced Kickback Chain
In my previous post about guidebars I mentioned that manufacturers make both regular and reduced kickback bars. I said that there wasn’t a tremendous difference between them and I saw no reason not to run the reduced kickback versions. The same is definitely not true for chain, where there is a tremendous difference between regular and reduced kickback versions.
This is an argument that the guys on ArboristSite REALLY like to engage in. Look no farther than this 8 page thread from 2009. There is another good one from 2010 also. In their world, reduced kickback chain is called “safety chain” and all safety chain is shit. My experience tells me that the real world isn’t so cut and dried. I started cutting long before the ANSI B 175.1 chainsaw safety standard was introduced in 1985. So reduced kickback chain wasn’t readily available until I had already been cutting for close to ten years. And current reduced kickback chain has improved tremendously over the stuff that was originally available.
That said, it is generally accepted that modern reduced kickback chain cuts a little slower and less aggressively than regular chain. This varies considerably between manufacturers and even within a manufacturer’s line between chain types. Because I am familiar with Stihl, that’s what I’ll use for my comparison.
When I bought my MS290, it came from the dealer with a loop of Stihl RSC3 full-chisel reduced kickback chain (identified by a green master link). When I first started the saw and cut with it I thought it worked pretty well, though it didn’t “pull” into the cut in the way I was used to with my old saw. But it cut well enough. After a while I switched over to a loop of RSC full-chisel regular chain. And the saw instantly felt more like I was used to. It really grabbed and pulled into the cut. But this same aggressiveness is what can make the saw kick back if the operator isn’t careful.
So I’m not going to get deep into this argument. From my personal experience, modern reduced kickback chain works well. I had no real problems with the RSC3 chain that came on my saw, and I certainly have the loop sharpened and ready to go. If I ever loaned my saw to someone, this is the chain I would give them until I really trusted them. But I admit that I do use the yellow link regular RSC chain most of the time. With all the years I have behind the saw I feel I’m prepared for the increased kickback potential. Your situation may be different. On your first saw I would always recommend a modern reduced kickback chain. Read the threads I referenced above if you want to learn more.
Good luck and safe cutting.