So I got this stuff in on a trade and I am not sure exactly what pitch or gauge it is. It is not marked. It is smaller than 3/8" so maybe it could be .325 I am not really sure. The box is marked 311 and I did find an old thread on the internet where someone was talking about .311 pitch chain but I have never delt with it. Probably more of a collectors item than anything else.. There is more than 3/4 of a roll here. It looks to be some sort of ripping or milling chain.. Please feel free to ask questions, and thank you for looking..