Hello I know this is probably not the correct forum, but i was wondering if anyone can tell me why the bolt that connects the two handles to my large tree pruner wont cut off or unscrew off? it very old and needs sharpening but cannot be sharpened unless i can separate the two handles, there is only one bolt holding them together. i could only unscrew the bolt off part way then it wont move. i tried cutting it off with a hack saw and it does not seem to even make a dent in it. any suggestions would be appreciated. Thanks