I was out with my brother harvestin’ this morning.

While cutting a log I noticed a tiny vibration along the length of the bar and suddenly without warning the chain snapped and shot off the end of the bar. The chain tension was good, the chain has only been sharpened a couple of times and appeared to be in good condition. It was a good quality chain.

We were both wearing PPE and neither of us were hurt but it was sobering to see the chain ejected as such a speed.

What could have caused it to break?

Nail in the tree?

Environmentalists used to bury nails in redwoods so that the chainsaw person would be injured when the chain snapped and flew out at 200mph…

Trapped chain in a Compression cut?

I was once marking a bridge deck level on a railway bridge. The timber bridge was being replaced in sections over weekend possessions. I just walked away as a chain flew through the air and embedded itself into a column where my head was about 10 seconds earlier.

We had a check for nails in the log and found nothing. The log I was cutting was about a foot across and I was about a third of the way through it when the chain snapped.

The chain tension was good. The chain and bar were fitted new together. Wartec chain – Oregon Bar

I wasn’t stressing the saw through the cut at all. Just cutting a log in two as you would on a saw horse.

I’d suggest the chain snapped where it was joined perhaps the rivet was over tight or the head was over spun flattening it and weakening it. Or because it is actually a shite chain from China.

I’d suggest the chain snapped where it was joined perhaps the rivet was over tight or the head was over spun flattening it and weakening it. Or because it is actually a shite chain from China.

I’ve looked over all the other teeth and links on the chain and can’t see any damage, so it looks like its simply a crap chain failure. Something of a bummer as these were slightly more expensive than the chains I’ve been using in the past. 😯

Check your drive sprocket for wear. Sometimes if a slot has been worn in to the sprocket, and you tension to it, if the chain jumps to a higher point on the sprocket it can over tension.

Looks like the rivet is missing could have just snapped , a bit like new bike chains snapping on the first ride one of those things but with potentially worse consequenses

Check your drive sprocket for wear. Sometimes if a slot has been worn in to the sprocket, and you tension to it, if the chain jumps to a higher point on the sprocket it can over tension.

The drive sprocket looked ok, but I think I will order a couple of new ones just in case. I have two identical saws so I can compare the two.

Looks like the rivet is missing could have just snapped , a bit like new bike chains snapping on the first ride one of those things but with potentially worse consequenses

I try never to stand above the chain and make sure no one is ever in line with chain. It’s not the sort of thing I’d like to see happen again.

And yet people are happy to chainsaw without ppe , incidents with saws happen so fast they’re almost out of your control.

As someone who used to make up a lot of chains as part of my job I’d saw that whoever riveted that didn’t do a very good job.

As has been mentioned, it’s probably where it was joined, the remaining rivet will look slightly different to the rest (factory join vs manual spinner). Had this problem at work on chains I’d joined. Turned out the plates were getting slightly bent because the splitting block was worn causing uneven wear on the joining rivet. A change of block later and have had no snapped chains since. Er.. touch wood.

When I was using a saw regularly I ran three chains on one sprocket, changing them round every couple of fuel refills to get more use out of them. Then changing all chains and sprocket at the same time when the chain wear had got beyond use. If it’s a new chain it may be mismatched to the sprocket.

In bike terms, it’s a bit like using the chain until it’s stretched so much that the chainrings are worn too and won’t work properly with a new chain rather than changing the chain earlier to get a bit more life out of the rings. Or something like that.