My first Stihl,023 came with the 3/8p chain on it. When I got the 250 I just figured it made sense to go with the same size chain since the buy 2 get one free at my dealer worked for me. I do like the .325 on the 026.I run .325" pitch semi-chisel with a 7-tooth sprocket to drive my Stihl MS251C, usually with either a 16"or 18" bar. The saw loves that. That's also what I use and recommend for the Stihl 025 and 026. I thus fear that I have to disagree with Farmer Steve on this one, and we seldom disagree.