I have a circular saw with an overly tightened arbor bolt and a blade that spins freely> How can I get that repaired? This saw was one that I inherited from my dad and I need to use it for some up and coming projects.
If "the bolt is tight, but the blade is loose" something is not assembled correctly, (missing or improperly positioned arbor washer) or you have the wrong blade (too thin) for the saw. Or perhaps you are a repeat of putting a round-hole saw blade on a saw designed for a diamond-shaped hole.
If by "overly tightened" you mean the bolt is stripped, you'll obviously need to replace it.
If the arbor is stripped, you'll need to use a Helicoil or some other repair technique to make it so that a bolt of the original size will work again. Obviously you can't drill and re-tap the arbor to a larger size.