Dealing With Stihl Chains: Part 1

When it comes to sharpening, identifying Oregon chains to get the requisite filing information is a relatively simple affair - look up the model number on the drive link, check the profile and consult the filing table.

Stihl, on the other hand, isn't quite as easy... or is it? Stihl have 'relatively recently' changed how they mark their chains, so I'm thinking it might be worth spending a few posts looking at how we can identify the various Stihl chains; starting with the most complex way and arriving at the simplest in a post or two (or more!) time.

The initial problem is that Stihl do not mark their chains with a model number, although the Stihl boxes that you buy a chain in do display model number. So first off, how can we correlate the model numbers on the box, with the markings on the chain? Well, I could just tell you the quick way, but as this is designed to be an educational site, we'll consider Stihl chains in a slightly wider context first of all, and then bring all the information together to identify our chain.

Pitch. There are a number of commonly available, industry standard pitch sizes - 1/4", 0.325", 3/8", 0.404" and 1/2" (unlikely to see that last though). On Stihl chains the pitch is stamped into the depth gauge, and you'll see "1/4", "325", "3/8", "404" or "1/2" (or at least you would have done before Stihl changed their markings!). You might also see the letter "P" stamped into the depth gauge too, and that denotes a Picco™ chain.

However, this has changed and now you'll see a number from 1 to 7 instead. So, "1" relates to a 1/4"; "2" relates to 0.325"; "3" is a 3/8" chain, "4" is a 0.404" pitch chain, "5" is a 1/2", "6" is the 3/8" (Picco™) and "7" is a 1/4" (Picco™) chain.

Remember those numbers, as the first character of the model number for the Stihl chain relates to the pitch; so a model 26 chain is a 0.325" pitch chain (as the "2" denotes a 0.325" pitch).

Let's leave that sink in first, and in the next post we'll get to grips with how the second character of the model number is derived.