The first thing that struck me when I took this tool out of the box was that the chain is replaceable. It's good and that's one of the reasons I bought it. But the discs that hold it all together are surprisingly thin. And when separated from a grinder or pneumatic tool, this tool just falls apart. There are no bolts or screws holding themselves together. This makes it easy to change the blade, but unless you're absolutely sure you're putting it back together correctly and that the discs aren't bent, the blade can slip off the discs and cut you. It is very easy to misassemble this tool. Never use these tools without guards.