Too big for #25 chain. The tips just don't fit between the plates. I was able to get it working by carefully sanding the tips, including the correct radius for #25 rollers, and it's working fine now. It probably won't work for the larger chain now, but I only use it with the #25 and #35. I suspect it will be too weak for the much larger chain. When I tighten the #25 chain the knob is quite hard to turn, but for a light chain that's fine. It's hard to believe that that's enough for a chain three times the size.