Could be the wrong bar. Length, pitch, and gauge is one thing, but the tail mount pattern, oil hole and all needs to match what a particular saw model requires. I got some bars that fit my Makita chainsaw well, but upon close inspection before even running it I noticed the oil hole on the bar did not line up where it needed to be, so I had to drill new holes. I was guessing when I got those bars, knowing I might have to modify them, but if you buy a good brand: Husqvarna or Oregon, and it says it will fit a 345 chainsaw, then there shouldn't be a problem.