It's fairly easy to straighten a sword blade. One simple method used by warriors of the centuries to fix a bent sword involved nothing more than taking the blade and bending in back into shape over a knee before wading back into combat.
These days of course, it is not necessary to straighten a sword blade in the heat of combat (at least if it is, you should seriously consider moving neighourhoods!) - and the most common reason to straighten a blade is because of a mishap during cutting (very common with differentially hardened Japanese blades) or because the blade did not arrive perfectly straight (extremely common on ALL levels of swords, some collectors are fussier than the sword makers).
The 'straightening over the knee method' is still a valid one - but you need to be extremely careful as one slip and you could end up in the nearest emergency ward.. So for a safer method, you might want to consider making the simple wooden tool made from two pieces of 2x4 about 12" to 14" long. (which can also be used on TWISTED blades, that are much harder to fix by hand).
Bear in mind that REPEATED bending and straightening of a sword will eventually cause the metal to become fatigued, however bending it 3 or 4 times should not be a problem.
I hope this simple tutorial on how to straighten a sword blade has been helpful. To return to Navigating the Sword Care Maze from How to Straighten a Sword Blade, click here