I have learned way more about saw chains today than I thought I ever wanted to know. It all started because I began looking into better ways to sharpen my chains.
When I was a kid, I used a round file, with no guide. It was a bit time consuming, and certainly far from perfect, but it was better than having a dull chain. This was before it ever occurred to me to buy new chains.
When I got the Stihl saw, I also got the 2-in-1 filing guide. I tried it once, and it just didn’t seem to be doing much, or doing it very consistently. I probably could have gotten good at it with practice, but I’m lazy, and I consider my time to be valuable.
Instead, however, I started sending my chains out to be sharpened. $8 per chain seemed like a good deal at first, especially if it saved me a bunch of hand filing. However, the first place cut the teeth nearly square. The second place charged me more for the longer chains. The third place cost me shipping one way. None of them came back looking as nice as they had when they were new. Most importantly, the time waiting for sharpening was interfering with my plans to get back out there, which meant I had to own more chains, but I still send them out in smaller batches.
The farm store where I frequently buy supplies for my saw had some no-name saw chain grinder for about $80. However, I decided I better learn more before buying it.
I finally started looking into them today. Harbor Freight has a $30 one that many people claim is the best one available. I watched some videos, and I could see how it was a bit janky compared to the better ones. I suppose if I was a $30 Harbor Freight kind of guy, I could have been quite happy with it, but instead I am a man of means and taste. I ended up ordering an Oregon 520-120, which I’m sure I will serve my needs quite abundantly.
In the process of researching grinders, I had to learn about all the adjustments that apply to different types of chain, which got me looking more closely at saw chains.
When I bought my saw, it came with a 20″ bar and Rapid Micro 3 (RM3) chain. I knew that it didn’t cut as aggressively as other chains, but I didn’t feel like I was in a hurry, and I was happy to have the reduced kick-back inherent in this chain. For a long time, I had tried to stick with RM3, but it has been difficult, because local suppliers often didn’t have it. This is particularly true for my 25″ bar, because I have never found 84-link RM3 chains stocked locally. Whenever I have asked for it, I’ve always been told that they don’t stock it because professionals don’t want it (a nice way of telling me I’m an amateur).
The market forced me to try RM and RS chain. RM is like RM3, except that it doesn’t have the drive link hump that reduces kick-back. RM was noticeably more aggressive than RM3, and it took me a few minutes to learn how to work with it. RS (Rapid Super) is like RM, but it has a full-chisel tooth instead of the semi-chisel tooth. This is supposed to make it cut more aggressively, but I haven’t been able to tell the difference between RM and RS.
Bending to market forces, I had decided recently to standardize on RS chain for my 25″ bar. I now have several 84-link RS chains and RM3 chains (although my RM3 chains are all in need of sharpening until the grinder arrives).
However, I am beginning to reconsider. Not only is the semi-chisel tooth purported to hold an edge longer, but this especially true in “dirty” conditions. Since trail maintenance frequently involves dead, decaying trees that have been on the ground for some time, I would say that the conditions count as dirty. One of the things I noticed about RS chain is that the angle of attack is more acute (60° instead of 75°), which probably has something to do with the difference in durability.
Therefore, I’m thinking that what I really should be standardizing on is RM chain. I just ordered a few more for my 20″ bar, and I will keep my eye out for some for my 25″ bar.