Removing stuck fasteners

In theory, there should be nothing to stop you finger-tightening a bolt until it's snug, or easily loosening a bolt once it has been fastened snugly. In practise, it's often quite hard to turn some bolts or loosen other bolts, even when they are slack. The reason for this is that dirt gets stuck in the bolt threads, and it gets trapped when you start tightening the bolt, making it harder to turn. This is a warning sign -- if you can't finger tighten a bolt until it's snug then there is something wrong. If you are trying to  put a bolt in, then take it out and clean the threads.  If you are trying to loosen or remove a stuck bolt, see if you can access the end of the bolt (opposite end of the bolt head).  Put a little grease on the threads before you try again. It's a bad to get out the spanner wrench early on to try tightening a bolt that isn't turning smoothly. Even if you get it tightened, that dirt is still in the threads, and it's quite likely that it'll jam the threads when you try to next remove the bolt.