In article , Tim Williams
wrote:

After much pain and anguish forging (hot and cold), annealing, filing and
sanding a nice 12" blade blank in 1090 (former beefy nail set), I've heat
treated it (all except the tang end is file hard) and it's currently in the
oven at 350 or 400 for the next hour. But it's got two good kinks in the
previously perfect straightness. And that'll make sharpening with a flat
stone annoying ... not to mention making it look stupid overall.
Suggestions?

Tim


Reheat it and straighten it while hot.
Then, heat it up again and bury in powdered lime or vermiculite.
Leave it for at least 4 hours.

This is called Annealing and will remove any stresses in the blade from
the forging process.

Clean up the blade.
Then re-harden it, this time making sure not to have an uneven heat on
either side of the blade before you quench.

Tempering in the oven is fine.